qid int64 1 74.7M | question stringlengths 12 33.8k | date stringlengths 10 10 | metadata list | response_j stringlengths 0 115k | response_k stringlengths 2 98.3k |
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157,765 | For a fantasy, I need to know how a world similar to Earth would exist in a geocentric model.
1) I would assume the sun would have to be a lot smaller. I'm okay with artificial stars (hand-wave that stuff away with magic). But I would like to know if that makes an Earth-similar planet impossible. (I don't need other planets in this model.) For example, how would it effect...
* seasons and climate
* length of day, month, or year
* sunrises and sunsets
* gravity
* constellations and/or navigation
* any huge effect I don't have enough science to anticipate
2) How would I manipulate my universe's model to make it more Earth similar if those things are completely off? It doesn't have to be exact, but I need a temperate climate with pretty normal seasons and climate zones. | 2019/10/06 | [
"https://worldbuilding.stackexchange.com/questions/157765",
"https://worldbuilding.stackexchange.com",
"https://worldbuilding.stackexchange.com/users/69409/"
] | The first thing we must understand is that from a purely *kinematic* point of view, the heliocentric and geocentric models are both equally correct within the accuracy limits of astronomical instruments available before the, say, 16th century. There was no way for an astronomer who lived before [Tycho Brahe](https://en.wikipedia.org/wiki/Tycho_Brahe) to bring serious arguments in favor of one or the other. (That's why Galileo Galilei had such trouble with the astronomical establishment of the day -- he simply did not have any good arguments to bring in favor of his pet theory.)
The problem is that from a *dynamic* point of view, for a geocentric model to be correct it is necessary to abolish the law of universal gravitation: and this means, of course, that the universe in which a geocentric model is correct from a physical point of view has vastly different physics from ours. Whether *"a world similar to Earth would exist"* in an universe with vastly different physics than ours is not something that anybody but you can answer.
How would it effect...
* Seasons and climate:
We don't know. The law of universal gravity doesn't work in your world, so we have no idea how wind works, how the water cycle works, the lot. By the way, how does *fire* work in a world where the law of universal gravity does not operate?
* Length of day, month, or year:
Those are purely kinematic phenomena, and from a purely kinematic point of view the heliocentric and geocentric models are both equally correct within the accuracy limits of astronomical instruments available before the Renaissance.
* Sunrises and sunsets:
The sun will rise and the sun will set. We have no idea how the atmosphere works, or how thick it is, because the law of universal gravitation doesn't work in that world. So we don't know if, for example, the sun will appear red at sunset.
* Gravity:
*Our* kind of gravity doesn't work in an universe where the geocentric model is correct. It must be some different force which is called gravity. How it works nobody but you, the author, can say.
* Constellations and/or navigation:
No effect whatsoever. The funny thing is that *up to this day* celestial navigation, as an application of practical astronomy, is done assuming a geocentric model. See [celestial sphere](https://en.wikipedia.org/wiki/Celestial_sphere) for how this works.
Of course, satellite-based navigation systems won't work, because the law of universal gravitation doesn't work.
* Any huge effect I don't have enough science to anticipate:
The main huge effect is that only the author can say how that world works, because it most definitely it doesn't work like ours. What keeps water in the ocean, what keeps people on the ground? Does hot air rise? Why? Are there tides? Why?
Note that you *do not* have to make Sun any smaller or bigger -- whether we adopt a heliocentric or geocentric system has no impact on the distance between the Earth and the Sun.
Everything also applies for the Moon. A Moon may or may not exist; if it exists, it is not universal gravitation which makes it orbit. What is it that keeps the Moon in orbit only the author can decide. | You have to limit the solar system to the planets visible by naked eye - or else starting from neptune they would need to rotate around your fantasy earth with more than the speed of light - which is impossible. Stars even increase this dilemma.
Your true problem lies in "epi-cycles" ... the visible paths that planets take on our nightsky. Even Ptolomaeus wrote 14 books to show and explain those epi-cycles: every planet has its own set, except for the inner planets Venus and Mercury.
Seasons are a problem because the geocentrist model needs the sun to actually move "up and down" between the tropics of cancer and capricorn to give the same path over the sky as can be viewed.
And finally what forces would govern the movement of those bodies? |
157,765 | For a fantasy, I need to know how a world similar to Earth would exist in a geocentric model.
1) I would assume the sun would have to be a lot smaller. I'm okay with artificial stars (hand-wave that stuff away with magic). But I would like to know if that makes an Earth-similar planet impossible. (I don't need other planets in this model.) For example, how would it effect...
* seasons and climate
* length of day, month, or year
* sunrises and sunsets
* gravity
* constellations and/or navigation
* any huge effect I don't have enough science to anticipate
2) How would I manipulate my universe's model to make it more Earth similar if those things are completely off? It doesn't have to be exact, but I need a temperate climate with pretty normal seasons and climate zones. | 2019/10/06 | [
"https://worldbuilding.stackexchange.com/questions/157765",
"https://worldbuilding.stackexchange.com",
"https://worldbuilding.stackexchange.com/users/69409/"
] | It would be perfectly possible for an extremely advanced civilization, perhaps humans of the future, to create a geocentric solar system.
They could take a rogue Earth-sized planet in interstellar space and create a giant sun satellite orbiting the planet with gigantic fusion power generators generating power for thousands of giant lamps aimed at the planet to heat it and warm it.
If they want the sidereal day of the Earth-sized planet to be similar to that of Earth (23 hours, 56 minutes, 4.0905 seconds) they will have to select an Earth-sized planet in interstellar space that rotates with a similar period and/or slow down or spreed up the rotation of the planet. If they do that the stars at night will seem to circle with the same speed as on Earth.
The giant artificial sun satellite will have to orbit at such a distance that the solar day (the time between two successive noons or midnights at the same location) will equal 24 hours. So that means that the time it takes for the giant artificial sun satellite to make one orbit combined with the time it takes for the planet to rotate once (the sidereal day) will equal 24 hours, a solar day on Earth. I'm certain there are some users at this site who can easily calculate the distance for you.
Of course there is the problem that the "moon" should orbit the Earth-sized planet at the same distance that the Moon orbits the Earth in order to have a month of the same length and similar tides.
>
> In Aristotle's (384–322 BC) description of the universe, the Moon marked the boundary between the spheres of the mutable elements (earth, water, air and fire), and the imperishable stars of aether, an influential philosophy that would dominate for centuries.[183] However, in the 2nd century BC, Seleucus of Seleucia correctly theorized that tides were due to the attraction of the Moon, and that their height depends on the Moon's position relative to the Sun.[184] In the same century, Aristarchus computed the size and distance of the Moon from Earth, obtaining a value of about twenty times the radius of Earth for the distance. These figures were greatly improved by Ptolemy (90–168 AD): his values of a mean distance of 59 times Earth's radius and a diameter of 0.292 Earth diameters were close to the correct values of about 60 and 0.273 respectively.[185] Archimedes (287–212 BC) designed a planetarium that could calculate the motions of the Moon and other objects in the Solar System.[186]
>
>
>
<https://en.wikipedia.org/wiki/Moon#Before_spaceflight>[1](https://en.wikipedia.org/wiki/Moon#Before_spaceflight)
So the size and distance of the Moon was measured reasonably accurately about 2,000 years ago. And a fake moon orbiting a fake earth in an artificial geocentric solar system would have to orbit the fake earth at a similar distance to that of the real Moon.
Which could be a farther distance than than the proper distance for the giant artificial sun satellite to orbit. Which would be bad because on Earth eclipses are caused by the nearer Moon passing in front of the farther Sun.
There are many other things to consider when designing a possible artificial geocentric solar system. But presumably some users on this board can do it for you.
A possibly simpler way to create an artificial geocentric solar system would be to find an Earth-sized rogue planet in interstellar space and build a gigantic artificial geodesic spherical structure around it and fit the inner surface of that spherical structure with countless gazillions of lamps. The lamps would be programmed to turn on and off in patterns to simulate the movements of the Sun, the Moon, the visible planets in the Solar System, and the stars.
So if it is scientifically possible for an advanced civilization to create an artificial geocentric solar system, a possibly artificial or natural geocentric solar system might exist in a science fiction story set in some parallel universe where the laws of science are different. And of course a natural geocentric solar system might exist in a fantasy story filled with magic.
As I remember, in J.R.R. Tolkien's legendarium the world was originally not only geocentric but flat, until a great cataclysm where the God of the story changed the Earth into a sphere and made the solar system heliocentric. | Not much ...
============
The three key bodies for life on Earth are Earth, Sun, and Moon. The Moon orbits Earth. The difference between the Earth orbiting the Sun and the Sun orbiting the Earth is one of reference frames, which are somewhat arbitrary.
*The only real difference is explaining the other planets and their moons.*
* In a heliocentric view, Earth is a planet like the others, orbiting the Sun. No special cases are necessary.
* In a pure geocentric view, Earth is unlike the other other planets, and you need *complicated* explanations for their paths.
Seasons, days, months, etc. are unchanged. Celestial navigation is greatly complicated on a global scale by the *weird* apparent paths of the stars. |
157,765 | For a fantasy, I need to know how a world similar to Earth would exist in a geocentric model.
1) I would assume the sun would have to be a lot smaller. I'm okay with artificial stars (hand-wave that stuff away with magic). But I would like to know if that makes an Earth-similar planet impossible. (I don't need other planets in this model.) For example, how would it effect...
* seasons and climate
* length of day, month, or year
* sunrises and sunsets
* gravity
* constellations and/or navigation
* any huge effect I don't have enough science to anticipate
2) How would I manipulate my universe's model to make it more Earth similar if those things are completely off? It doesn't have to be exact, but I need a temperate climate with pretty normal seasons and climate zones. | 2019/10/06 | [
"https://worldbuilding.stackexchange.com/questions/157765",
"https://worldbuilding.stackexchange.com",
"https://worldbuilding.stackexchange.com/users/69409/"
] | The first thing we must understand is that from a purely *kinematic* point of view, the heliocentric and geocentric models are both equally correct within the accuracy limits of astronomical instruments available before the, say, 16th century. There was no way for an astronomer who lived before [Tycho Brahe](https://en.wikipedia.org/wiki/Tycho_Brahe) to bring serious arguments in favor of one or the other. (That's why Galileo Galilei had such trouble with the astronomical establishment of the day -- he simply did not have any good arguments to bring in favor of his pet theory.)
The problem is that from a *dynamic* point of view, for a geocentric model to be correct it is necessary to abolish the law of universal gravitation: and this means, of course, that the universe in which a geocentric model is correct from a physical point of view has vastly different physics from ours. Whether *"a world similar to Earth would exist"* in an universe with vastly different physics than ours is not something that anybody but you can answer.
How would it effect...
* Seasons and climate:
We don't know. The law of universal gravity doesn't work in your world, so we have no idea how wind works, how the water cycle works, the lot. By the way, how does *fire* work in a world where the law of universal gravity does not operate?
* Length of day, month, or year:
Those are purely kinematic phenomena, and from a purely kinematic point of view the heliocentric and geocentric models are both equally correct within the accuracy limits of astronomical instruments available before the Renaissance.
* Sunrises and sunsets:
The sun will rise and the sun will set. We have no idea how the atmosphere works, or how thick it is, because the law of universal gravitation doesn't work in that world. So we don't know if, for example, the sun will appear red at sunset.
* Gravity:
*Our* kind of gravity doesn't work in an universe where the geocentric model is correct. It must be some different force which is called gravity. How it works nobody but you, the author, can say.
* Constellations and/or navigation:
No effect whatsoever. The funny thing is that *up to this day* celestial navigation, as an application of practical astronomy, is done assuming a geocentric model. See [celestial sphere](https://en.wikipedia.org/wiki/Celestial_sphere) for how this works.
Of course, satellite-based navigation systems won't work, because the law of universal gravitation doesn't work.
* Any huge effect I don't have enough science to anticipate:
The main huge effect is that only the author can say how that world works, because it most definitely it doesn't work like ours. What keeps water in the ocean, what keeps people on the ground? Does hot air rise? Why? Are there tides? Why?
Note that you *do not* have to make Sun any smaller or bigger -- whether we adopt a heliocentric or geocentric system has no impact on the distance between the Earth and the Sun.
Everything also applies for the Moon. A Moon may or may not exist; if it exists, it is not universal gravitation which makes it orbit. What is it that keeps the Moon in orbit only the author can decide. | Assuming that Newtonian mechanics still apply the factor that determines whether the Earth goes around the Sun or the Sun around the Earth is the mass of the sun. If the sun radiates equally in all directions then its total power output must be proportional to its distance from the Earth.
Assuming that the mass of the Sun is small compared to that of the Earth, an orbital period of 30Ms (about 1 year) gives a radius of about 2Gm corresponding to a sphere with a surface area of about 5.5E19 m^2. For a power density of 1.361 W/m^2 the Sun must produce 7.4E22 W. If it burns at this rate for about one billion years then it will consume about 2.5E22 kg of matter. For comparison, the mass of the Earth is about 6E24 kg, so if you postulate a light-weight machine with a store of fuel which it converts to energy and radiates in all directions then this arrangement could be plausible.
However, if you have a machine converting fuel to sunlight then why assume that it will waste most of it? If it could focus its entire output on the Earth then it could reduce its power consumption by a factor of about 430,000 and at the same time make the mechanism more easily accessible for the maintenance crew.
Unfortunately the radiation pressure would push the Sun away from the Earth, so perhaps it should radiate an equal amount in the opposite direction. This would produce as a biproduct an interesting galactic lighthouse.
From the perspective of a fairly primitive civilisation this should be almost indistinguishable from a heliocentric system. Weather would be similar, although I am not sure what effect the absence of the Sun's magnetic field would have. If you want a moon like Earth's then you must make arrangements to illuminate it. Maybe spread the beam in the plane of the Moon's orbit, or even provide a separately focused beam. Comets would be interesting, as they would now be orbiting the Earth rather than the sun, and they would abruptly disappear as the passed out of the beam. |
157,765 | For a fantasy, I need to know how a world similar to Earth would exist in a geocentric model.
1) I would assume the sun would have to be a lot smaller. I'm okay with artificial stars (hand-wave that stuff away with magic). But I would like to know if that makes an Earth-similar planet impossible. (I don't need other planets in this model.) For example, how would it effect...
* seasons and climate
* length of day, month, or year
* sunrises and sunsets
* gravity
* constellations and/or navigation
* any huge effect I don't have enough science to anticipate
2) How would I manipulate my universe's model to make it more Earth similar if those things are completely off? It doesn't have to be exact, but I need a temperate climate with pretty normal seasons and climate zones. | 2019/10/06 | [
"https://worldbuilding.stackexchange.com/questions/157765",
"https://worldbuilding.stackexchange.com",
"https://worldbuilding.stackexchange.com/users/69409/"
] | The first thing we must understand is that from a purely *kinematic* point of view, the heliocentric and geocentric models are both equally correct within the accuracy limits of astronomical instruments available before the, say, 16th century. There was no way for an astronomer who lived before [Tycho Brahe](https://en.wikipedia.org/wiki/Tycho_Brahe) to bring serious arguments in favor of one or the other. (That's why Galileo Galilei had such trouble with the astronomical establishment of the day -- he simply did not have any good arguments to bring in favor of his pet theory.)
The problem is that from a *dynamic* point of view, for a geocentric model to be correct it is necessary to abolish the law of universal gravitation: and this means, of course, that the universe in which a geocentric model is correct from a physical point of view has vastly different physics from ours. Whether *"a world similar to Earth would exist"* in an universe with vastly different physics than ours is not something that anybody but you can answer.
How would it effect...
* Seasons and climate:
We don't know. The law of universal gravity doesn't work in your world, so we have no idea how wind works, how the water cycle works, the lot. By the way, how does *fire* work in a world where the law of universal gravity does not operate?
* Length of day, month, or year:
Those are purely kinematic phenomena, and from a purely kinematic point of view the heliocentric and geocentric models are both equally correct within the accuracy limits of astronomical instruments available before the Renaissance.
* Sunrises and sunsets:
The sun will rise and the sun will set. We have no idea how the atmosphere works, or how thick it is, because the law of universal gravitation doesn't work in that world. So we don't know if, for example, the sun will appear red at sunset.
* Gravity:
*Our* kind of gravity doesn't work in an universe where the geocentric model is correct. It must be some different force which is called gravity. How it works nobody but you, the author, can say.
* Constellations and/or navigation:
No effect whatsoever. The funny thing is that *up to this day* celestial navigation, as an application of practical astronomy, is done assuming a geocentric model. See [celestial sphere](https://en.wikipedia.org/wiki/Celestial_sphere) for how this works.
Of course, satellite-based navigation systems won't work, because the law of universal gravitation doesn't work.
* Any huge effect I don't have enough science to anticipate:
The main huge effect is that only the author can say how that world works, because it most definitely it doesn't work like ours. What keeps water in the ocean, what keeps people on the ground? Does hot air rise? Why? Are there tides? Why?
Note that you *do not* have to make Sun any smaller or bigger -- whether we adopt a heliocentric or geocentric system has no impact on the distance between the Earth and the Sun.
Everything also applies for the Moon. A Moon may or may not exist; if it exists, it is not universal gravitation which makes it orbit. What is it that keeps the Moon in orbit only the author can decide. | It would be perfectly possible for an extremely advanced civilization, perhaps humans of the future, to create a geocentric solar system.
They could take a rogue Earth-sized planet in interstellar space and create a giant sun satellite orbiting the planet with gigantic fusion power generators generating power for thousands of giant lamps aimed at the planet to heat it and warm it.
If they want the sidereal day of the Earth-sized planet to be similar to that of Earth (23 hours, 56 minutes, 4.0905 seconds) they will have to select an Earth-sized planet in interstellar space that rotates with a similar period and/or slow down or spreed up the rotation of the planet. If they do that the stars at night will seem to circle with the same speed as on Earth.
The giant artificial sun satellite will have to orbit at such a distance that the solar day (the time between two successive noons or midnights at the same location) will equal 24 hours. So that means that the time it takes for the giant artificial sun satellite to make one orbit combined with the time it takes for the planet to rotate once (the sidereal day) will equal 24 hours, a solar day on Earth. I'm certain there are some users at this site who can easily calculate the distance for you.
Of course there is the problem that the "moon" should orbit the Earth-sized planet at the same distance that the Moon orbits the Earth in order to have a month of the same length and similar tides.
>
> In Aristotle's (384–322 BC) description of the universe, the Moon marked the boundary between the spheres of the mutable elements (earth, water, air and fire), and the imperishable stars of aether, an influential philosophy that would dominate for centuries.[183] However, in the 2nd century BC, Seleucus of Seleucia correctly theorized that tides were due to the attraction of the Moon, and that their height depends on the Moon's position relative to the Sun.[184] In the same century, Aristarchus computed the size and distance of the Moon from Earth, obtaining a value of about twenty times the radius of Earth for the distance. These figures were greatly improved by Ptolemy (90–168 AD): his values of a mean distance of 59 times Earth's radius and a diameter of 0.292 Earth diameters were close to the correct values of about 60 and 0.273 respectively.[185] Archimedes (287–212 BC) designed a planetarium that could calculate the motions of the Moon and other objects in the Solar System.[186]
>
>
>
<https://en.wikipedia.org/wiki/Moon#Before_spaceflight>[1](https://en.wikipedia.org/wiki/Moon#Before_spaceflight)
So the size and distance of the Moon was measured reasonably accurately about 2,000 years ago. And a fake moon orbiting a fake earth in an artificial geocentric solar system would have to orbit the fake earth at a similar distance to that of the real Moon.
Which could be a farther distance than than the proper distance for the giant artificial sun satellite to orbit. Which would be bad because on Earth eclipses are caused by the nearer Moon passing in front of the farther Sun.
There are many other things to consider when designing a possible artificial geocentric solar system. But presumably some users on this board can do it for you.
A possibly simpler way to create an artificial geocentric solar system would be to find an Earth-sized rogue planet in interstellar space and build a gigantic artificial geodesic spherical structure around it and fit the inner surface of that spherical structure with countless gazillions of lamps. The lamps would be programmed to turn on and off in patterns to simulate the movements of the Sun, the Moon, the visible planets in the Solar System, and the stars.
So if it is scientifically possible for an advanced civilization to create an artificial geocentric solar system, a possibly artificial or natural geocentric solar system might exist in a science fiction story set in some parallel universe where the laws of science are different. And of course a natural geocentric solar system might exist in a fantasy story filled with magic.
As I remember, in J.R.R. Tolkien's legendarium the world was originally not only geocentric but flat, until a great cataclysm where the God of the story changed the Earth into a sphere and made the solar system heliocentric. |
157,765 | For a fantasy, I need to know how a world similar to Earth would exist in a geocentric model.
1) I would assume the sun would have to be a lot smaller. I'm okay with artificial stars (hand-wave that stuff away with magic). But I would like to know if that makes an Earth-similar planet impossible. (I don't need other planets in this model.) For example, how would it effect...
* seasons and climate
* length of day, month, or year
* sunrises and sunsets
* gravity
* constellations and/or navigation
* any huge effect I don't have enough science to anticipate
2) How would I manipulate my universe's model to make it more Earth similar if those things are completely off? It doesn't have to be exact, but I need a temperate climate with pretty normal seasons and climate zones. | 2019/10/06 | [
"https://worldbuilding.stackexchange.com/questions/157765",
"https://worldbuilding.stackexchange.com",
"https://worldbuilding.stackexchange.com/users/69409/"
] | Not much ...
============
The three key bodies for life on Earth are Earth, Sun, and Moon. The Moon orbits Earth. The difference between the Earth orbiting the Sun and the Sun orbiting the Earth is one of reference frames, which are somewhat arbitrary.
*The only real difference is explaining the other planets and their moons.*
* In a heliocentric view, Earth is a planet like the others, orbiting the Sun. No special cases are necessary.
* In a pure geocentric view, Earth is unlike the other other planets, and you need *complicated* explanations for their paths.
Seasons, days, months, etc. are unchanged. Celestial navigation is greatly complicated on a global scale by the *weird* apparent paths of the stars. | Assuming that Newtonian mechanics still apply the factor that determines whether the Earth goes around the Sun or the Sun around the Earth is the mass of the sun. If the sun radiates equally in all directions then its total power output must be proportional to its distance from the Earth.
Assuming that the mass of the Sun is small compared to that of the Earth, an orbital period of 30Ms (about 1 year) gives a radius of about 2Gm corresponding to a sphere with a surface area of about 5.5E19 m^2. For a power density of 1.361 W/m^2 the Sun must produce 7.4E22 W. If it burns at this rate for about one billion years then it will consume about 2.5E22 kg of matter. For comparison, the mass of the Earth is about 6E24 kg, so if you postulate a light-weight machine with a store of fuel which it converts to energy and radiates in all directions then this arrangement could be plausible.
However, if you have a machine converting fuel to sunlight then why assume that it will waste most of it? If it could focus its entire output on the Earth then it could reduce its power consumption by a factor of about 430,000 and at the same time make the mechanism more easily accessible for the maintenance crew.
Unfortunately the radiation pressure would push the Sun away from the Earth, so perhaps it should radiate an equal amount in the opposite direction. This would produce as a biproduct an interesting galactic lighthouse.
From the perspective of a fairly primitive civilisation this should be almost indistinguishable from a heliocentric system. Weather would be similar, although I am not sure what effect the absence of the Sun's magnetic field would have. If you want a moon like Earth's then you must make arrangements to illuminate it. Maybe spread the beam in the plane of the Moon's orbit, or even provide a separately focused beam. Comets would be interesting, as they would now be orbiting the Earth rather than the sun, and they would abruptly disappear as the passed out of the beam. |
157,765 | For a fantasy, I need to know how a world similar to Earth would exist in a geocentric model.
1) I would assume the sun would have to be a lot smaller. I'm okay with artificial stars (hand-wave that stuff away with magic). But I would like to know if that makes an Earth-similar planet impossible. (I don't need other planets in this model.) For example, how would it effect...
* seasons and climate
* length of day, month, or year
* sunrises and sunsets
* gravity
* constellations and/or navigation
* any huge effect I don't have enough science to anticipate
2) How would I manipulate my universe's model to make it more Earth similar if those things are completely off? It doesn't have to be exact, but I need a temperate climate with pretty normal seasons and climate zones. | 2019/10/06 | [
"https://worldbuilding.stackexchange.com/questions/157765",
"https://worldbuilding.stackexchange.com",
"https://worldbuilding.stackexchange.com/users/69409/"
] | The first thing we must understand is that from a purely *kinematic* point of view, the heliocentric and geocentric models are both equally correct within the accuracy limits of astronomical instruments available before the, say, 16th century. There was no way for an astronomer who lived before [Tycho Brahe](https://en.wikipedia.org/wiki/Tycho_Brahe) to bring serious arguments in favor of one or the other. (That's why Galileo Galilei had such trouble with the astronomical establishment of the day -- he simply did not have any good arguments to bring in favor of his pet theory.)
The problem is that from a *dynamic* point of view, for a geocentric model to be correct it is necessary to abolish the law of universal gravitation: and this means, of course, that the universe in which a geocentric model is correct from a physical point of view has vastly different physics from ours. Whether *"a world similar to Earth would exist"* in an universe with vastly different physics than ours is not something that anybody but you can answer.
How would it effect...
* Seasons and climate:
We don't know. The law of universal gravity doesn't work in your world, so we have no idea how wind works, how the water cycle works, the lot. By the way, how does *fire* work in a world where the law of universal gravity does not operate?
* Length of day, month, or year:
Those are purely kinematic phenomena, and from a purely kinematic point of view the heliocentric and geocentric models are both equally correct within the accuracy limits of astronomical instruments available before the Renaissance.
* Sunrises and sunsets:
The sun will rise and the sun will set. We have no idea how the atmosphere works, or how thick it is, because the law of universal gravitation doesn't work in that world. So we don't know if, for example, the sun will appear red at sunset.
* Gravity:
*Our* kind of gravity doesn't work in an universe where the geocentric model is correct. It must be some different force which is called gravity. How it works nobody but you, the author, can say.
* Constellations and/or navigation:
No effect whatsoever. The funny thing is that *up to this day* celestial navigation, as an application of practical astronomy, is done assuming a geocentric model. See [celestial sphere](https://en.wikipedia.org/wiki/Celestial_sphere) for how this works.
Of course, satellite-based navigation systems won't work, because the law of universal gravitation doesn't work.
* Any huge effect I don't have enough science to anticipate:
The main huge effect is that only the author can say how that world works, because it most definitely it doesn't work like ours. What keeps water in the ocean, what keeps people on the ground? Does hot air rise? Why? Are there tides? Why?
Note that you *do not* have to make Sun any smaller or bigger -- whether we adopt a heliocentric or geocentric system has no impact on the distance between the Earth and the Sun.
Everything also applies for the Moon. A Moon may or may not exist; if it exists, it is not universal gravitation which makes it orbit. What is it that keeps the Moon in orbit only the author can decide. | You don't have to change much at all, if you don't force yourself to follow Newtonian mechanics to explain planetary motions.
For one, universal gravitation was not mainstream until Newton built his system around it. Until then, it seemed possible that other heavenly bodies might not exert any kind of gravity at all. If you use this approach, then you don't have to worry about the size of these other bodies, or what they might do to your Earth (Although you might want to give the moon gravitational pull if you want tides).
People also once theorized that the other heavenly bodies moved in fixed tracks around the Earth; if you are willing to assert that some divine being fixed a track (perfect circles, for instance), then you can make them go wherever you want, as fast as you want, and you don't have to give a scientific justification for it.
If you're doing fantasy, there's no reason you should feel committed to being Newtonian about everything. Heavenly bodies were once thought to follow different laws than earthly ones; you could make that a reality in your world. This would also give you a lot of freedom to shape them as you like. |
284,763 | How can gravitational potential be negative?
Gravitation energy increases as we go higher. How is this possible when it is negative?
Please give an intuitive explanation.
Actually I'm confused by this statement: "Gravitational potential energy increases as we go higher but still remains negative."
My doubt is almost cleared by all of your explanations (thanks, btw), but there is still one thing:- Consider two points A and B and B higher than A. Gravitational potential energy is lower at A that is it's more negative or in other words potential energy at B is closer to zero or less negative. But **magnitude of the potential energy at A is greater than B**, that is the absolute value is more for A but still it's at lower potential. This is what I always end up thinking and get confused. I have not got any satisfactory answer to this question :( | 2016/10/07 | [
"https://physics.stackexchange.com/questions/284763",
"https://physics.stackexchange.com",
"https://physics.stackexchange.com/users/132249/"
] | You almost answered your own question. If you increase potential energy by going up, then you decrease by going down. Decreasing means becoming more negative. So, being in a gravity well causes an object to have less total energy than an object not in a gravity well, all else equal. If you say 0 potential energy due to gravity is at a place far far away from any gravity well, then it must be negative in a gravity well. That means you have to pay energy to climb out of a well. | OK Drop a 10 kg object from a height of 10 meters. It will gain speed as it falls, and so kinetic energy. At the bottom, catch it in such a way that you charge a battery by using the kinetic energy and bring it to stop.
Just by making the object fall for 10 meters, you were able to collect some energy. This energy comes from somewhere - and that is decrease in gravitational potential.
The decrease means negative.
As we know that same object would not fall by itself in far space, we can not collect energy in this way, or we can say we can only collect 0 energy. So, the the gravitational potential in far space is 0. If you decrease something from 0, it becomes negative. If you increase something from negative, it will reach 0.
But if your question refers to why it is negative in philosophical sense - means there is no such thing as negative energy. Then I agree, it is a "decrease", not "negative". The "decrease" itself is a real (positive) amount. negative amounts are not real even though negative numbers are real numbers. For example, there is no such thing as -5 kg mass. You can decrease mass of a 10 kg mass object by 5 kg by taking 5 kg mass away. But that 5 kg will remain a 5 kg mass wherever you take it. There is no -5 kg mass.
Therefore it is "decreased" gravitational potential of the combined (earth and object) system, which is written as negative potential.
When the object is in far space, the 0 potential refers only to the object because earth is not in the picture in that case. Only when it comes in earth's gravitational influence, we start talking about the potential of the combined system.
While saying 0 potential of the object in far space, I am ignoring the small potential of the object due to its own constituent mass.
"Point B higher than A" means you have to spend energy in moving from point A to B. This way you are adding energy to the potential of the system and so, the total potential increases. (say from -10 at A to -5 at B). -10 at A means you have to spent 10 units of energy in moving from A to far space. -5 at B means you have to spend 5 units of energy in moving from B to far space. So negative potential at a point is actually amount of positive energy you have to spend in moving from that point to far space. Conversely, when you move from far space to A, you gain 10 units of kinetic energy. B is at a higher potential (-5) than A (-10). Higher potential of B means you have to spend lesser amount of energy to move from B to far space. That is why it is -5 at B and considered higher than -10 at A. Give it few days to think multiple times and you will get it. Trying to get it in one go may not be as productive. |
284,763 | How can gravitational potential be negative?
Gravitation energy increases as we go higher. How is this possible when it is negative?
Please give an intuitive explanation.
Actually I'm confused by this statement: "Gravitational potential energy increases as we go higher but still remains negative."
My doubt is almost cleared by all of your explanations (thanks, btw), but there is still one thing:- Consider two points A and B and B higher than A. Gravitational potential energy is lower at A that is it's more negative or in other words potential energy at B is closer to zero or less negative. But **magnitude of the potential energy at A is greater than B**, that is the absolute value is more for A but still it's at lower potential. This is what I always end up thinking and get confused. I have not got any satisfactory answer to this question :( | 2016/10/07 | [
"https://physics.stackexchange.com/questions/284763",
"https://physics.stackexchange.com",
"https://physics.stackexchange.com/users/132249/"
] | Around a point-like object, the gravitational potential is singular as the distance decreases to zero, thus you can't use it as a ground potential.
The only meaningful alternative to use the infinite distance as zero potential.
But, to preserve energy, objects coming from near-infinite, they get kinetical energy, this is coming by the decrease in the gravitation well. Thus the gravitational energy should be negative.
If you revert the convention, i.e. to have a positive gravitational potential, then
1. you should revert also the kinetical energy. It is weird
2. or you have to find a different zero reference point (it also weird + occasional, you have to explain, why)
3. or you will harm energy preservation (-> give up useful physics)
Note, if you calculate some easy thing, for example you are calculating the gravitational energy of an elevator in a high school homework task, you can use the ground as zero reference without any problem. It falls to (2): you essentially selected 6636km distance as zero potential in the gravity well of the Earth. | OK Drop a 10 kg object from a height of 10 meters. It will gain speed as it falls, and so kinetic energy. At the bottom, catch it in such a way that you charge a battery by using the kinetic energy and bring it to stop.
Just by making the object fall for 10 meters, you were able to collect some energy. This energy comes from somewhere - and that is decrease in gravitational potential.
The decrease means negative.
As we know that same object would not fall by itself in far space, we can not collect energy in this way, or we can say we can only collect 0 energy. So, the the gravitational potential in far space is 0. If you decrease something from 0, it becomes negative. If you increase something from negative, it will reach 0.
But if your question refers to why it is negative in philosophical sense - means there is no such thing as negative energy. Then I agree, it is a "decrease", not "negative". The "decrease" itself is a real (positive) amount. negative amounts are not real even though negative numbers are real numbers. For example, there is no such thing as -5 kg mass. You can decrease mass of a 10 kg mass object by 5 kg by taking 5 kg mass away. But that 5 kg will remain a 5 kg mass wherever you take it. There is no -5 kg mass.
Therefore it is "decreased" gravitational potential of the combined (earth and object) system, which is written as negative potential.
When the object is in far space, the 0 potential refers only to the object because earth is not in the picture in that case. Only when it comes in earth's gravitational influence, we start talking about the potential of the combined system.
While saying 0 potential of the object in far space, I am ignoring the small potential of the object due to its own constituent mass.
"Point B higher than A" means you have to spend energy in moving from point A to B. This way you are adding energy to the potential of the system and so, the total potential increases. (say from -10 at A to -5 at B). -10 at A means you have to spent 10 units of energy in moving from A to far space. -5 at B means you have to spend 5 units of energy in moving from B to far space. So negative potential at a point is actually amount of positive energy you have to spend in moving from that point to far space. Conversely, when you move from far space to A, you gain 10 units of kinetic energy. B is at a higher potential (-5) than A (-10). Higher potential of B means you have to spend lesser amount of energy to move from B to far space. That is why it is -5 at B and considered higher than -10 at A. Give it few days to think multiple times and you will get it. Trying to get it in one go may not be as productive. |
509,481 | I see a lot of text on the internet and here telling us how to de-bounce a switch, in my case a push button. But I have tried all these circuits and I find that nothing other than a 555 monostable worked for me so far.
This is why I ask that you only answer if your knowledge is *practical*, not textbook, not hear-say, only if you have done it either recently or often enough that you have experienced the difference between theory and practice!
I have tried RC with inverter and that doesn't work except with Schmitt-trigger inverter (and I guess then Schmitt trigger buffer too), but even that not 100% reliably (I would say one extra triggering in about 100.)
My test setup is without a storage scope, just a 74LS161 counter and 4 LEDs hooked up.
My preferred solution is an S-R-latch, with 2 NAND gates (74LS00), but I had no luck whatsoever with that, regardless whether I tied the switch to high or to ground.
One thing nobody seems to mention is the darned make-before-break variety of push-button switches. Those are a total non-starter. But now that I just came home with 2 more buttons, tested and found them to be break-before-make, hooked them up to my DYI S-R-latch and I still get salves of up to more than 16 counts! Rarely, but I can't count a set of 16 without at least one double trigger.
Why am I the only one who has such bad luck? I show you my breadboard photos if you don't believe me. I put it on YouTube.
This is why I don't trust any theoretical answers, I built every circuit in the book(s) and can testify for several of them they totally and utterly fail right out the barn. I think most people who write about this don't actually have the experience.
So far RC with Schmitt-trigger is the only thing I could get working at 99% reliability, but not better, and I don't want the monostable, I really want the S-R latch (push - S, release - R).
**UPDATE:** people want to see schematics, so here is what I am now targeting. I have built all other circuits I could find. I will try the RC again from one of the answers. But for the SR-latch it's this:
[simulate this circuit](/plugins/schematics?image=http%3a%2f%2fi.stack.imgur.com%2foGuWx.png) – Schematic created using [CircuitLab](https://www.circuitlab.com/)
I have three different types of double throw buttons, all I can get my my hands on, and one is MBB, doesn't work, the other is one of those with a little lever, like a morse code switch, supposedly extra precise, but nope, it bounces back and forth. The other is a button like the first but BBM -- at least most of the time.
I find that the double throw buttons are all bad. The third one is the best, but still it has horrible bouncing around, because when I hold it just right it can even do a MBB action. So, that may be the problem I am having. I just can't get a decent switch.
This means, for me the SR-latch trick is out, a no-go.
I need to use a single throw button then and try again with RC. I will work off the other answer below and report back.
**UPDATE:** I see a lot of negative ratings, but I don't care! I am here representing the experimental truth of the matter and not text book. Yes, we are on breadboards but these things do not work.
It probably has to do with the fact that the double throw buttons are all bad, at least in micro-switch format, they bounce around like crazy, make-before-break and apparently also bouncing between the two sides. The only circuit that I can use to do an push-release action with <10% glitch rate is the one I have described here:
[Is it possible to use just a capacitor to debounce a button?](https://electronics.stackexchange.com/questions/64770/is-it-possible-to-use-just-a-capacitor-to-debounce-a-button/506498#506498) | 2020/07/08 | [
"https://electronics.stackexchange.com/questions/509481",
"https://electronics.stackexchange.com",
"https://electronics.stackexchange.com/users/235839/"
] | Your problem is not knowing input impedance chances with bias voltage on TTL.
TTL floats to a logic "1" input with Iin =0 uA at 2x Vbe drops or ~1.3V . This is unlike CMOS.
* The impedance is infinite when floating at this voltage. But at 0.4V the input impedance is 1K due the common base input bias current.
* To ensure the TTL has a safe margin or a valid "1" input > 2V the input impedance is > 100K with 20uA max at 2.7V.
* So to make it work, I biased the input towards the tipping point of input current between 1 and 0 so that the target voltage is lowered and transition time is extended during switch bounce.
* this is somewhat nonlinear Ohm's Law so I won't explain beyond this for now.
* Naturally, a Schmitt Trigger works better but still not good enough unless you use a much larger Cap.
For a 10ms bounce time and T=RC= 10ms so C=10ms/3.3k = 3uF
[simulate this circuit](/plugins/schematics?image=http%3a%2f%2fi.stack.imgur.com%2frZx7C.png) – Schematic created using [CircuitLab](https://www.circuitlab.com/)
This is one way to do it with short twisted pair wires.
Decoupling cap MUST be near IC and much larger to absorb the transient.
some Hypothetical causes for failure.
* Using TTL instead of CMOS. (requires a different solution.)
* Not using a decoupling cap
* excessive long sig/ground wires.
* Must be Break Before Make (common type) switch.
**It is much preferred to use 2 momentary switches to gnd or toggle 1 switch using TTL due to the large input current.**
So learn to use CMOS instead. Input Impedance is > 10M but beware of ESD even if protected. | You have no series resistors on your LEDs, which is naughty and eats up noise margin, especially if the LEDs are red color.
You do not show any bypass capacitors. You NEED a bypass capacitor quite near each chip, 100nF ceramic is a good value.
Quite likely your problems will go away when you fix those things. |
509,481 | I see a lot of text on the internet and here telling us how to de-bounce a switch, in my case a push button. But I have tried all these circuits and I find that nothing other than a 555 monostable worked for me so far.
This is why I ask that you only answer if your knowledge is *practical*, not textbook, not hear-say, only if you have done it either recently or often enough that you have experienced the difference between theory and practice!
I have tried RC with inverter and that doesn't work except with Schmitt-trigger inverter (and I guess then Schmitt trigger buffer too), but even that not 100% reliably (I would say one extra triggering in about 100.)
My test setup is without a storage scope, just a 74LS161 counter and 4 LEDs hooked up.
My preferred solution is an S-R-latch, with 2 NAND gates (74LS00), but I had no luck whatsoever with that, regardless whether I tied the switch to high or to ground.
One thing nobody seems to mention is the darned make-before-break variety of push-button switches. Those are a total non-starter. But now that I just came home with 2 more buttons, tested and found them to be break-before-make, hooked them up to my DYI S-R-latch and I still get salves of up to more than 16 counts! Rarely, but I can't count a set of 16 without at least one double trigger.
Why am I the only one who has such bad luck? I show you my breadboard photos if you don't believe me. I put it on YouTube.
This is why I don't trust any theoretical answers, I built every circuit in the book(s) and can testify for several of them they totally and utterly fail right out the barn. I think most people who write about this don't actually have the experience.
So far RC with Schmitt-trigger is the only thing I could get working at 99% reliability, but not better, and I don't want the monostable, I really want the S-R latch (push - S, release - R).
**UPDATE:** people want to see schematics, so here is what I am now targeting. I have built all other circuits I could find. I will try the RC again from one of the answers. But for the SR-latch it's this:
[simulate this circuit](/plugins/schematics?image=http%3a%2f%2fi.stack.imgur.com%2foGuWx.png) – Schematic created using [CircuitLab](https://www.circuitlab.com/)
I have three different types of double throw buttons, all I can get my my hands on, and one is MBB, doesn't work, the other is one of those with a little lever, like a morse code switch, supposedly extra precise, but nope, it bounces back and forth. The other is a button like the first but BBM -- at least most of the time.
I find that the double throw buttons are all bad. The third one is the best, but still it has horrible bouncing around, because when I hold it just right it can even do a MBB action. So, that may be the problem I am having. I just can't get a decent switch.
This means, for me the SR-latch trick is out, a no-go.
I need to use a single throw button then and try again with RC. I will work off the other answer below and report back.
**UPDATE:** I see a lot of negative ratings, but I don't care! I am here representing the experimental truth of the matter and not text book. Yes, we are on breadboards but these things do not work.
It probably has to do with the fact that the double throw buttons are all bad, at least in micro-switch format, they bounce around like crazy, make-before-break and apparently also bouncing between the two sides. The only circuit that I can use to do an push-release action with <10% glitch rate is the one I have described here:
[Is it possible to use just a capacitor to debounce a button?](https://electronics.stackexchange.com/questions/64770/is-it-possible-to-use-just-a-capacitor-to-debounce-a-button/506498#506498) | 2020/07/08 | [
"https://electronics.stackexchange.com/questions/509481",
"https://electronics.stackexchange.com",
"https://electronics.stackexchange.com/users/235839/"
] | Your problem is not knowing input impedance chances with bias voltage on TTL.
TTL floats to a logic "1" input with Iin =0 uA at 2x Vbe drops or ~1.3V . This is unlike CMOS.
* The impedance is infinite when floating at this voltage. But at 0.4V the input impedance is 1K due the common base input bias current.
* To ensure the TTL has a safe margin or a valid "1" input > 2V the input impedance is > 100K with 20uA max at 2.7V.
* So to make it work, I biased the input towards the tipping point of input current between 1 and 0 so that the target voltage is lowered and transition time is extended during switch bounce.
* this is somewhat nonlinear Ohm's Law so I won't explain beyond this for now.
* Naturally, a Schmitt Trigger works better but still not good enough unless you use a much larger Cap.
For a 10ms bounce time and T=RC= 10ms so C=10ms/3.3k = 3uF
[simulate this circuit](/plugins/schematics?image=http%3a%2f%2fi.stack.imgur.com%2frZx7C.png) – Schematic created using [CircuitLab](https://www.circuitlab.com/)
This is one way to do it with short twisted pair wires.
Decoupling cap MUST be near IC and much larger to absorb the transient.
some Hypothetical causes for failure.
* Using TTL instead of CMOS. (requires a different solution.)
* Not using a decoupling cap
* excessive long sig/ground wires.
* Must be Break Before Make (common type) switch.
**It is much preferred to use 2 momentary switches to gnd or toggle 1 switch using TTL due to the large input current.**
So learn to use CMOS instead. Input Impedance is > 10M but beware of ESD even if protected. | If you really have LEDs connected between logic signals and ground without current-limiting resistors, that's your problem! LSTTL does not have a lot of high-side drive to begin with, and the bare LED will completely overload it, killing your valid logic levels.
Basically, a red LED has a forward voltage drop somewhere in the vicinity of 1.7 V, and it will easily pull a high LSTTL output down to this level. However, the minimum VIH for a TTL input is 2.0 V — which means that you're operating with a **negative** noise margin. It's no wonder that the counter behaves in a flaky manner.
If you really want to monitor signal levels, buffer your LEDs with 'LS04 inverters, and connect the LED between the 'LS04 output and Vcc **with** a 330-ohm series resistor. The LED will light up when the 'LS04 input is high, as desired.
[simulate this circuit](/plugins/schematics?image=http%3a%2f%2fi.stack.imgur.com%2fWNscR.png) – Schematic created using [CircuitLab](https://www.circuitlab.com/)
---
And just to demonstrate that I do indeed have "real world experience" in this area, here are a couple of photographs of a project I did back in the mid-1970s when I was still in high school. It's a "breadboard helper" that includes (left to right):
* A variable-speed 555 oscillator (note the metal can!)
* 8 DIP switches to ground
* 8 buffered digital monitors
* 2 debounced pushbuttons
The PCB was hand-drawn with a Sharpie pen. The circuit for the debounced pushbuttons is very simple, and you can see that the switch construction is pretty much the cheapest possible. Always worked perfectly.
[simulate this circuit](/plugins/schematics?image=http%3a%2f%2fi.stack.imgur.com%2fsmM11m.png)
[](https://i.stack.imgur.com/pE3SA.jpg)
[](https://i.stack.imgur.com/xoPD9.jpg) |
509,481 | I see a lot of text on the internet and here telling us how to de-bounce a switch, in my case a push button. But I have tried all these circuits and I find that nothing other than a 555 monostable worked for me so far.
This is why I ask that you only answer if your knowledge is *practical*, not textbook, not hear-say, only if you have done it either recently or often enough that you have experienced the difference between theory and practice!
I have tried RC with inverter and that doesn't work except with Schmitt-trigger inverter (and I guess then Schmitt trigger buffer too), but even that not 100% reliably (I would say one extra triggering in about 100.)
My test setup is without a storage scope, just a 74LS161 counter and 4 LEDs hooked up.
My preferred solution is an S-R-latch, with 2 NAND gates (74LS00), but I had no luck whatsoever with that, regardless whether I tied the switch to high or to ground.
One thing nobody seems to mention is the darned make-before-break variety of push-button switches. Those are a total non-starter. But now that I just came home with 2 more buttons, tested and found them to be break-before-make, hooked them up to my DYI S-R-latch and I still get salves of up to more than 16 counts! Rarely, but I can't count a set of 16 without at least one double trigger.
Why am I the only one who has such bad luck? I show you my breadboard photos if you don't believe me. I put it on YouTube.
This is why I don't trust any theoretical answers, I built every circuit in the book(s) and can testify for several of them they totally and utterly fail right out the barn. I think most people who write about this don't actually have the experience.
So far RC with Schmitt-trigger is the only thing I could get working at 99% reliability, but not better, and I don't want the monostable, I really want the S-R latch (push - S, release - R).
**UPDATE:** people want to see schematics, so here is what I am now targeting. I have built all other circuits I could find. I will try the RC again from one of the answers. But for the SR-latch it's this:
[simulate this circuit](/plugins/schematics?image=http%3a%2f%2fi.stack.imgur.com%2foGuWx.png) – Schematic created using [CircuitLab](https://www.circuitlab.com/)
I have three different types of double throw buttons, all I can get my my hands on, and one is MBB, doesn't work, the other is one of those with a little lever, like a morse code switch, supposedly extra precise, but nope, it bounces back and forth. The other is a button like the first but BBM -- at least most of the time.
I find that the double throw buttons are all bad. The third one is the best, but still it has horrible bouncing around, because when I hold it just right it can even do a MBB action. So, that may be the problem I am having. I just can't get a decent switch.
This means, for me the SR-latch trick is out, a no-go.
I need to use a single throw button then and try again with RC. I will work off the other answer below and report back.
**UPDATE:** I see a lot of negative ratings, but I don't care! I am here representing the experimental truth of the matter and not text book. Yes, we are on breadboards but these things do not work.
It probably has to do with the fact that the double throw buttons are all bad, at least in micro-switch format, they bounce around like crazy, make-before-break and apparently also bouncing between the two sides. The only circuit that I can use to do an push-release action with <10% glitch rate is the one I have described here:
[Is it possible to use just a capacitor to debounce a button?](https://electronics.stackexchange.com/questions/64770/is-it-possible-to-use-just-a-capacitor-to-debounce-a-button/506498#506498) | 2020/07/08 | [
"https://electronics.stackexchange.com/questions/509481",
"https://electronics.stackexchange.com",
"https://electronics.stackexchange.com/users/235839/"
] | This always works.
The two push buttons can be replaced by a SPDT switch.
[simulate this circuit](/plugins/schematics?image=http%3a%2f%2fi.stack.imgur.com%2fgCp4P.png) – Schematic created using [CircuitLab](https://www.circuitlab.com/)
[Here is a simulation](https://falstad.com/circuit/circuitjs.html?cct=$+1+0.000005+10.20027730826997+50+5+43%0A151+224+160+304+160+0+2+0+5%0A151+224+288+304+288+0+2+5+5%0Aw+224+176+224+208+0%0Aw+224+208+336+208+0%0Aw+336+208+336+288+0%0Aw+304+288+336+288+0%0Aw+304+160+320+160+0%0Aw+320+160+320+240+0%0Aw+320+240+224+240+0%0Aw+224+240+224+272+0%0Aw+144+144+144+192+0%0Ag+80+272+80+304+0%0A162+320+160+432+160+2+default-led+1+0+0+0.01%0Ag+432+160+432+192+0%0AR+176+80+176+64+0+0+40+5+0+0+0.5%0AR+176+240+176+224+0+0+40+5+0+0+0.5%0Ar+176+80+176+144+0+1000%0Ar+176+240+176+304+0+1000%0Aw+144+304+176+304+0%0Aw+176+304+224+304+0%0Aw+144+144+176+144+0%0Aw+176+144+224+144+0%0As+80+256+144+256+0+1+true%0As+80+192+144+192+0+1+true%0Aw+80+272+80+256+0%0Aw+80+256+80+192+0%0Aw+144+256+144+304+0%0A) | You have no series resistors on your LEDs, which is naughty and eats up noise margin, especially if the LEDs are red color.
You do not show any bypass capacitors. You NEED a bypass capacitor quite near each chip, 100nF ceramic is a good value.
Quite likely your problems will go away when you fix those things. |
509,481 | I see a lot of text on the internet and here telling us how to de-bounce a switch, in my case a push button. But I have tried all these circuits and I find that nothing other than a 555 monostable worked for me so far.
This is why I ask that you only answer if your knowledge is *practical*, not textbook, not hear-say, only if you have done it either recently or often enough that you have experienced the difference between theory and practice!
I have tried RC with inverter and that doesn't work except with Schmitt-trigger inverter (and I guess then Schmitt trigger buffer too), but even that not 100% reliably (I would say one extra triggering in about 100.)
My test setup is without a storage scope, just a 74LS161 counter and 4 LEDs hooked up.
My preferred solution is an S-R-latch, with 2 NAND gates (74LS00), but I had no luck whatsoever with that, regardless whether I tied the switch to high or to ground.
One thing nobody seems to mention is the darned make-before-break variety of push-button switches. Those are a total non-starter. But now that I just came home with 2 more buttons, tested and found them to be break-before-make, hooked them up to my DYI S-R-latch and I still get salves of up to more than 16 counts! Rarely, but I can't count a set of 16 without at least one double trigger.
Why am I the only one who has such bad luck? I show you my breadboard photos if you don't believe me. I put it on YouTube.
This is why I don't trust any theoretical answers, I built every circuit in the book(s) and can testify for several of them they totally and utterly fail right out the barn. I think most people who write about this don't actually have the experience.
So far RC with Schmitt-trigger is the only thing I could get working at 99% reliability, but not better, and I don't want the monostable, I really want the S-R latch (push - S, release - R).
**UPDATE:** people want to see schematics, so here is what I am now targeting. I have built all other circuits I could find. I will try the RC again from one of the answers. But for the SR-latch it's this:
[simulate this circuit](/plugins/schematics?image=http%3a%2f%2fi.stack.imgur.com%2foGuWx.png) – Schematic created using [CircuitLab](https://www.circuitlab.com/)
I have three different types of double throw buttons, all I can get my my hands on, and one is MBB, doesn't work, the other is one of those with a little lever, like a morse code switch, supposedly extra precise, but nope, it bounces back and forth. The other is a button like the first but BBM -- at least most of the time.
I find that the double throw buttons are all bad. The third one is the best, but still it has horrible bouncing around, because when I hold it just right it can even do a MBB action. So, that may be the problem I am having. I just can't get a decent switch.
This means, for me the SR-latch trick is out, a no-go.
I need to use a single throw button then and try again with RC. I will work off the other answer below and report back.
**UPDATE:** I see a lot of negative ratings, but I don't care! I am here representing the experimental truth of the matter and not text book. Yes, we are on breadboards but these things do not work.
It probably has to do with the fact that the double throw buttons are all bad, at least in micro-switch format, they bounce around like crazy, make-before-break and apparently also bouncing between the two sides. The only circuit that I can use to do an push-release action with <10% glitch rate is the one I have described here:
[Is it possible to use just a capacitor to debounce a button?](https://electronics.stackexchange.com/questions/64770/is-it-possible-to-use-just-a-capacitor-to-debounce-a-button/506498#506498) | 2020/07/08 | [
"https://electronics.stackexchange.com/questions/509481",
"https://electronics.stackexchange.com",
"https://electronics.stackexchange.com/users/235839/"
] | This always works.
The two push buttons can be replaced by a SPDT switch.
[simulate this circuit](/plugins/schematics?image=http%3a%2f%2fi.stack.imgur.com%2fgCp4P.png) – Schematic created using [CircuitLab](https://www.circuitlab.com/)
[Here is a simulation](https://falstad.com/circuit/circuitjs.html?cct=$+1+0.000005+10.20027730826997+50+5+43%0A151+224+160+304+160+0+2+0+5%0A151+224+288+304+288+0+2+5+5%0Aw+224+176+224+208+0%0Aw+224+208+336+208+0%0Aw+336+208+336+288+0%0Aw+304+288+336+288+0%0Aw+304+160+320+160+0%0Aw+320+160+320+240+0%0Aw+320+240+224+240+0%0Aw+224+240+224+272+0%0Aw+144+144+144+192+0%0Ag+80+272+80+304+0%0A162+320+160+432+160+2+default-led+1+0+0+0.01%0Ag+432+160+432+192+0%0AR+176+80+176+64+0+0+40+5+0+0+0.5%0AR+176+240+176+224+0+0+40+5+0+0+0.5%0Ar+176+80+176+144+0+1000%0Ar+176+240+176+304+0+1000%0Aw+144+304+176+304+0%0Aw+176+304+224+304+0%0Aw+144+144+176+144+0%0Aw+176+144+224+144+0%0As+80+256+144+256+0+1+true%0As+80+192+144+192+0+1+true%0Aw+80+272+80+256+0%0Aw+80+256+80+192+0%0Aw+144+256+144+304+0%0A) | If you really have LEDs connected between logic signals and ground without current-limiting resistors, that's your problem! LSTTL does not have a lot of high-side drive to begin with, and the bare LED will completely overload it, killing your valid logic levels.
Basically, a red LED has a forward voltage drop somewhere in the vicinity of 1.7 V, and it will easily pull a high LSTTL output down to this level. However, the minimum VIH for a TTL input is 2.0 V — which means that you're operating with a **negative** noise margin. It's no wonder that the counter behaves in a flaky manner.
If you really want to monitor signal levels, buffer your LEDs with 'LS04 inverters, and connect the LED between the 'LS04 output and Vcc **with** a 330-ohm series resistor. The LED will light up when the 'LS04 input is high, as desired.
[simulate this circuit](/plugins/schematics?image=http%3a%2f%2fi.stack.imgur.com%2fWNscR.png) – Schematic created using [CircuitLab](https://www.circuitlab.com/)
---
And just to demonstrate that I do indeed have "real world experience" in this area, here are a couple of photographs of a project I did back in the mid-1970s when I was still in high school. It's a "breadboard helper" that includes (left to right):
* A variable-speed 555 oscillator (note the metal can!)
* 8 DIP switches to ground
* 8 buffered digital monitors
* 2 debounced pushbuttons
The PCB was hand-drawn with a Sharpie pen. The circuit for the debounced pushbuttons is very simple, and you can see that the switch construction is pretty much the cheapest possible. Always worked perfectly.
[simulate this circuit](/plugins/schematics?image=http%3a%2f%2fi.stack.imgur.com%2fsmM11m.png)
[](https://i.stack.imgur.com/pE3SA.jpg)
[](https://i.stack.imgur.com/xoPD9.jpg) |
752,456 | i Was wondering what people are using for logging in .net.
We have log4net here, but am looking to do it async and to a database
with a nice viewer.
What are the popular choices??
Regards. | 2009/04/15 | [
"https://Stackoverflow.com/questions/752456",
"https://Stackoverflow.com",
"https://Stackoverflow.com/users/32333/"
] | Log4Net delivers log messages to appenders synchronously, but the appenders can behave asynchronously [according to this](http://www.mail-archive.com/log4net-user@logging.apache.org/msg02168.html). The SqlServerAppender has a bufferSize property that controls how many log events are collected in the buffer before they are written to the database. If that doesn't meet your needs, you could write your own appender. A reply in [this post](http://www.l4ndash.com/Log4NetMailArchive/tabid/70/forumid/1/postid/15068/view/topic/Default.aspx) appears to give a working example. | We simply log to the database on error because we are a heavily used OLTP system.
If the DB goes down, then the system is down: asynch logging when the phones are red hot is redundant... |
752,456 | i Was wondering what people are using for logging in .net.
We have log4net here, but am looking to do it async and to a database
with a nice viewer.
What are the popular choices??
Regards. | 2009/04/15 | [
"https://Stackoverflow.com/questions/752456",
"https://Stackoverflow.com",
"https://Stackoverflow.com/users/32333/"
] | I would highly recommend looking into [NLOG](http://www.nlog-project.org/). It's very flexible and logs asynchronously. You can configure it to log to a specific file or DB. However, you'll need to build your own log viewer.
We use NLOG religiously and couldn't be happier with it. | We simply log to the database on error because we are a heavily used OLTP system.
If the DB goes down, then the system is down: asynch logging when the phones are red hot is redundant... |
752,456 | i Was wondering what people are using for logging in .net.
We have log4net here, but am looking to do it async and to a database
with a nice viewer.
What are the popular choices??
Regards. | 2009/04/15 | [
"https://Stackoverflow.com/questions/752456",
"https://Stackoverflow.com",
"https://Stackoverflow.com/users/32333/"
] | When we did this, we simply wrote to a simple internal queue and had a thread do the actual write. This way our code that was logging is minimally impacted, and the simple queue and thread managed keeping us up to date. | We simply log to the database on error because we are a heavily used OLTP system.
If the DB goes down, then the system is down: asynch logging when the phones are red hot is redundant... |
752,456 | i Was wondering what people are using for logging in .net.
We have log4net here, but am looking to do it async and to a database
with a nice viewer.
What are the popular choices??
Regards. | 2009/04/15 | [
"https://Stackoverflow.com/questions/752456",
"https://Stackoverflow.com",
"https://Stackoverflow.com/users/32333/"
] | Try **[logFaces](http://www.moonlit-software.com)**, it's centralized log server, aggregator and viewer, works nicely with log4net UDP appender.
**Disclosure**: I am the author of this product. | We simply log to the database on error because we are a heavily used OLTP system.
If the DB goes down, then the system is down: asynch logging when the phones are red hot is redundant... |
752,456 | i Was wondering what people are using for logging in .net.
We have log4net here, but am looking to do it async and to a database
with a nice viewer.
What are the popular choices??
Regards. | 2009/04/15 | [
"https://Stackoverflow.com/questions/752456",
"https://Stackoverflow.com",
"https://Stackoverflow.com/users/32333/"
] | Log4Net delivers log messages to appenders synchronously, but the appenders can behave asynchronously [according to this](http://www.mail-archive.com/log4net-user@logging.apache.org/msg02168.html). The SqlServerAppender has a bufferSize property that controls how many log events are collected in the buffer before they are written to the database. If that doesn't meet your needs, you could write your own appender. A reply in [this post](http://www.l4ndash.com/Log4NetMailArchive/tabid/70/forumid/1/postid/15068/view/topic/Default.aspx) appears to give a working example. | I've seen references to people having used the Microsoft Enterprise Library logging facility, in combination with MSMQ, to achieve asynchronous logging. No help on the viewer. |
752,456 | i Was wondering what people are using for logging in .net.
We have log4net here, but am looking to do it async and to a database
with a nice viewer.
What are the popular choices??
Regards. | 2009/04/15 | [
"https://Stackoverflow.com/questions/752456",
"https://Stackoverflow.com",
"https://Stackoverflow.com/users/32333/"
] | I would highly recommend looking into [NLOG](http://www.nlog-project.org/). It's very flexible and logs asynchronously. You can configure it to log to a specific file or DB. However, you'll need to build your own log viewer.
We use NLOG religiously and couldn't be happier with it. | I've seen references to people having used the Microsoft Enterprise Library logging facility, in combination with MSMQ, to achieve asynchronous logging. No help on the viewer. |
752,456 | i Was wondering what people are using for logging in .net.
We have log4net here, but am looking to do it async and to a database
with a nice viewer.
What are the popular choices??
Regards. | 2009/04/15 | [
"https://Stackoverflow.com/questions/752456",
"https://Stackoverflow.com",
"https://Stackoverflow.com/users/32333/"
] | When we did this, we simply wrote to a simple internal queue and had a thread do the actual write. This way our code that was logging is minimally impacted, and the simple queue and thread managed keeping us up to date. | I've seen references to people having used the Microsoft Enterprise Library logging facility, in combination with MSMQ, to achieve asynchronous logging. No help on the viewer. |
752,456 | i Was wondering what people are using for logging in .net.
We have log4net here, but am looking to do it async and to a database
with a nice viewer.
What are the popular choices??
Regards. | 2009/04/15 | [
"https://Stackoverflow.com/questions/752456",
"https://Stackoverflow.com",
"https://Stackoverflow.com/users/32333/"
] | Try **[logFaces](http://www.moonlit-software.com)**, it's centralized log server, aggregator and viewer, works nicely with log4net UDP appender.
**Disclosure**: I am the author of this product. | I've seen references to people having used the Microsoft Enterprise Library logging facility, in combination with MSMQ, to achieve asynchronous logging. No help on the viewer. |
51,046 | Situaltion:
* I have a windows forms application which is currently only available in german for the end user
* There is an existing userbase which gets auto updates
* The application is already translated to english in our dev branch
* The apps main window is a ribbon form
Now I want to allow the user to switch between german and english (more languages will follow) and I am thinking on how to implement the option to change the language.
I thought about a ribbon group with little flags for every language available.
The flags are greyed out except from the current selected.
The ribbon section shows up to six icons and more are shown only if you extend the section (ribbon standard)
Of course the current selected languge, the current users local are always shown
This seems to be a simple approach to me but than again I have never seen something similar in a windows forms application so I am wondering if this is a good idea or if I should use a different concept. | 2014/01/27 | [
"https://ux.stackexchange.com/questions/51046",
"https://ux.stackexchange.com",
"https://ux.stackexchange.com/users/41673/"
] | Using a dropdown of languages positioned appropriately on the form of course would be ideal. One - you can just add more languages to the dropdown in the future. Two, you can display the language in the dropdown in native script. Three, assuming you add 20 languages in the future, scroll on the dropdown won't be an issue, whereas content would scroll inside the ribbon. | It can also be done this way
A language icon could be placed somewhere on the top bar, On mouse hover (or on click) a language drop-down or a small div to place the other language flags. When the user selects a particular language flag, it replaces the previous one.This would save space on the page and is also user friendly. |
10,098 | It has become clear that I need to practice my transfer techniques; I just completed a primary-to-secondary transfer which involved what I'm guessing is a fairly significant amount of aeration. During my transfer (1-gallon basic brown beer, direct from carboy to carboy; no intermediate pot), I used an auto-siphon, and ended up pumping oxygen in. In addition, there was air in the line even while the beer was flowing (which I had to restart several times).
Ultimately, if a beer gets aerated, is it a solid bet that the beer will be oxidized and pick up that "musty, cardboard, stale odor and flavor"? Should I not get my hopes up, or might things still work out?
**Update:**
Last night, I opened one of the bottles. Much to my surprise, it was *not* awful! The carbonation was a little low, it could have had more flavor, and it was a *little* stale, but it was not the disaster that I was expecting. Hooray! | 2013/06/02 | [
"https://homebrew.stackexchange.com/questions/10098",
"https://homebrew.stackexchange.com",
"https://homebrew.stackexchange.com/users/3466/"
] | The bubbles are large so although some oxygen will have been absorbed it's not as much as say sloshing the beer around in the carboy for 60 seconds.
The beer will probably oxidize in time, say 2-4 weeks, but you can do two things to mitigate this:
1. drink the beer within a couple of weeks
2. store the beer at fridge temp. This will reduce the rate of staling considerably compared to storing at room temp.
With these measures, the beer should not oxidize much before it's been consumed. | Why would you need to restart the siphon several times? With an auto-siphon, you should have one or two strokes of the wand, and then it siphons until finished.
Also, why are you doing a transfer to secondary at all?
As for air in the line during the transfer, I find if I pinch, rotate and/or constrict the flow near that point where a bubble is present, you can usually "fill it in", and get the bubble to clear. |
10,098 | It has become clear that I need to practice my transfer techniques; I just completed a primary-to-secondary transfer which involved what I'm guessing is a fairly significant amount of aeration. During my transfer (1-gallon basic brown beer, direct from carboy to carboy; no intermediate pot), I used an auto-siphon, and ended up pumping oxygen in. In addition, there was air in the line even while the beer was flowing (which I had to restart several times).
Ultimately, if a beer gets aerated, is it a solid bet that the beer will be oxidized and pick up that "musty, cardboard, stale odor and flavor"? Should I not get my hopes up, or might things still work out?
**Update:**
Last night, I opened one of the bottles. Much to my surprise, it was *not* awful! The carbonation was a little low, it could have had more flavor, and it was a *little* stale, but it was not the disaster that I was expecting. Hooray! | 2013/06/02 | [
"https://homebrew.stackexchange.com/questions/10098",
"https://homebrew.stackexchange.com",
"https://homebrew.stackexchange.com/users/3466/"
] | I'd say keep your hopes up. Unless you pumped a ton of air through it, I don't think it will absorb as much as you think it will. The real problem comes when you slosh it around in the carboy afterwards if you are moving it to a fermentation vessel or closet somewhere, since you removed the layer of CO2 that was resting on top of the carboy and replaced it with oxygen. If this is a concern, transfer it where the secondary carboy will be sitting for secondary fermentation, and don't move it, or use a CO2 tank from a kegging system to purge out the oxygen with CO2 before capping it with an airlock and moving it around.
Try a few basic things to keep from oxidyzing during transfer:
1. Keep the "out" end of the rubber hose submerged in the beer in the secondary carboy until the very end of the transfer has completed. Also, keep it at the bottom of the carboy, so it isn't splashing when beer goes in.
2. Keep the "in" end of the siphon always submerged in your primary vessel.
3. With your auto siphon, don't ever use it to transfer hot (as in a boiling or near-boiling) liquid, as it will deform the auto siphon and may ruin the seals necessary to keep air out when transferring (personal experience on this one, my first half-assed attempt at fly-sparging).
4. Depending on the platforms you are transferring to and from (where your two carboys are at when siphoning), make sure you have more than enough tubing for your siphon. Don't cut yourself short and have to complicate your siphoning process by stacking books under carboys or moving chairs around, just keep it simple and get the right amount plus a foot or two extra, it'll save you a huge amount of hassle.
With experience you'll get better, you just need to try it a few times to get it right. The important ones are steps 1 and 2 above. As long as you keep both ends of the siphon submerged during transfer (past the beginning couple of seconds), there's no way for air to mysteriously get in until the very end, at which point you simply pull either end out and the suction will not pull further air into the wort. | Why would you need to restart the siphon several times? With an auto-siphon, you should have one or two strokes of the wand, and then it siphons until finished.
Also, why are you doing a transfer to secondary at all?
As for air in the line during the transfer, I find if I pinch, rotate and/or constrict the flow near that point where a bubble is present, you can usually "fill it in", and get the bubble to clear. |
34,829 | What plugins/techniques du you use? I make TONS of passbys in my work (space ships, cars etc), and i'm always looking to improve my sounds.
Thanks:) | 2015/03/31 | [
"https://sound.stackexchange.com/questions/34829",
"https://sound.stackexchange.com",
"https://sound.stackexchange.com/users/13258/"
] | Great question - there are SO MANY WAYS to achieve the effect you are talking about. A few of my favorites (at the moment) are:
1. Doppler plugins: Waves Doppler and GRM Doppler are the most common and yield instant results with very little effort. Unfortunately, these results can often sound pretty generic and lifeless, depending on your source material.
2. Level and EQ manipulation: This method is a throwback to the way "they used to do it". In short, by riding the fader level (amplitude) and tweaking EQ dips and curves, you can approximate the Doppler effect as it would sound in the real world. Because, if you think it through, all the Doppler effect is is "the change in frequency of a wave for an observer moving relative to its source". As a sound moves towards or away from you, not only is the amplitude changing but also the way the sound is moving through the air. Riding levels and twisting EQ knobs will deliver that same effect.
3. Flanging: This one is easily overlooked. A very slight amount of flanging can trick the brain into thinking it hears the effects of motion on a sound.
4. Stand-alone software: Programs like MetaSynth, NI Whoosh Machine and WaveWarper employ a bunch of processing/automating to achieve this effect. I've especially enjoying the WaveWarper method lately as you can manually drive layers of sounds over the Doppler point, giving you control over when the sound peaks and how the EQ will affect that peak point.
Just a few ideas, your mileage may vary... | Try worldizing. I noticed some sounds feel more natural when you play the them via a good speaker and swish your microphone against it. :) |
8,720,886 | I would like know what is the difference between the Quartz Scheduler and JMS, and in what situations is better to do the use of the tools... | 2012/01/04 | [
"https://Stackoverflow.com/questions/8720886",
"https://Stackoverflow.com",
"https://Stackoverflow.com/users/117682/"
] | They are completely different. One is an event scheduler, the other is a messaging / queuing technology. | [Quartz](http://www.quartz-scheduler.org/) is a library/product for scheduling jobs (just as you cronjobs on most UNIX systems). You can find a little turorial and example of using Quartz [here](http://www.ibm.com/developerworks/java/library/j-quartz/).
On the other hand:
>
> The Java Message Service (JMS) API is a Java Message Oriented
> Middleware (MOM) API [1](http://www.quartz-scheduler.org/) for sending messages between two or more
> clients
>
>
> |
8,720,886 | I would like know what is the difference between the Quartz Scheduler and JMS, and in what situations is better to do the use of the tools... | 2012/01/04 | [
"https://Stackoverflow.com/questions/8720886",
"https://Stackoverflow.com",
"https://Stackoverflow.com/users/117682/"
] | They are completely different. One is an event scheduler, the other is a messaging / queuing technology. | One other difference is that Quartz is a ready-to-use **product**, and JMS is only a **specification** (requires you to select an implementation to use it). |
8,720,886 | I would like know what is the difference between the Quartz Scheduler and JMS, and in what situations is better to do the use of the tools... | 2012/01/04 | [
"https://Stackoverflow.com/questions/8720886",
"https://Stackoverflow.com",
"https://Stackoverflow.com/users/117682/"
] | The Quartz scheduler is basically about running tasks in / to a schedule. For example, "do XYZ at 10 am every Friday".
JMS is about reliable sending, queueing and delivery of messages between different Java programs (clients) potentially running on different machines.
>
> ... in what situations is better to do the use of the tools.
>
>
>
As you can see they perform mostly unrelated functions. Use which ever provides the functionality that you actually need ... or both if you need both scheduling and queuing. | [Quartz](http://www.quartz-scheduler.org/) is a library/product for scheduling jobs (just as you cronjobs on most UNIX systems). You can find a little turorial and example of using Quartz [here](http://www.ibm.com/developerworks/java/library/j-quartz/).
On the other hand:
>
> The Java Message Service (JMS) API is a Java Message Oriented
> Middleware (MOM) API [1](http://www.quartz-scheduler.org/) for sending messages between two or more
> clients
>
>
> |
8,720,886 | I would like know what is the difference between the Quartz Scheduler and JMS, and in what situations is better to do the use of the tools... | 2012/01/04 | [
"https://Stackoverflow.com/questions/8720886",
"https://Stackoverflow.com",
"https://Stackoverflow.com/users/117682/"
] | The Quartz scheduler is basically about running tasks in / to a schedule. For example, "do XYZ at 10 am every Friday".
JMS is about reliable sending, queueing and delivery of messages between different Java programs (clients) potentially running on different machines.
>
> ... in what situations is better to do the use of the tools.
>
>
>
As you can see they perform mostly unrelated functions. Use which ever provides the functionality that you actually need ... or both if you need both scheduling and queuing. | One other difference is that Quartz is a ready-to-use **product**, and JMS is only a **specification** (requires you to select an implementation to use it). |
8,335 | In *Fringe*, there is the "Over Here" universe and the "Over there" universe that the characters interact with.
Why do only these two universes exist? Dr. Bishop mentioned that there were an unlimited number of universes existing at the same time.
I thought it was because it was the other universe that Walter went into that caused all the Fringe incidents, but in Walters experiments, he created a wall that only looked into the other universe, not any of the other universes.
Why are these two universes so important and not all the others? | 2011/12/30 | [
"https://scifi.stackexchange.com/questions/8335",
"https://scifi.stackexchange.com",
"https://scifi.stackexchange.com/users/1109/"
] | The universes are now connected because of the first cross over by Walter, so that's why it's possible to cross over between them in the present (although it continues not being easy for "normal people")
I think that Walter first created the window to that universe by chance, and the connection only intensified once he crossed over to save Peter. | In the Season 3 finale,
>
> Peter influenced events in the future, and altered the past. He stated in that episode that, somehow, they *are* the First People - due to a semi-stable time loop, it was the Fringe teams that put the device in the past to be found during the course of the series.
>
>
>
That event linked (or possibly split) the two universes, as the machine exist in both universes. Bolivia only stole what they couldn't find on Over There.
As of mid-season 4,
>
> Peter now believes he's in a 3rd/4th universe.
>
>
>
**EDIT:** Events in the series after this answer was posted shows us that the second spoiler is false - he was incorrect. |
8,335 | In *Fringe*, there is the "Over Here" universe and the "Over there" universe that the characters interact with.
Why do only these two universes exist? Dr. Bishop mentioned that there were an unlimited number of universes existing at the same time.
I thought it was because it was the other universe that Walter went into that caused all the Fringe incidents, but in Walters experiments, he created a wall that only looked into the other universe, not any of the other universes.
Why are these two universes so important and not all the others? | 2011/12/30 | [
"https://scifi.stackexchange.com/questions/8335",
"https://scifi.stackexchange.com",
"https://scifi.stackexchange.com/users/1109/"
] | The universes are now connected because of the first cross over by Walter, so that's why it's possible to cross over between them in the present (although it continues not being easy for "normal people")
I think that Walter first created the window to that universe by chance, and the connection only intensified once he crossed over to save Peter. | Both Nina and Bell indicate in the Second season that the two Universes are moving towards each other ever since Walter first Bridged the worlds. Hence the snow-globe collision metaphor. Since then travel between those Universes would be easier than between "Over Here" and any other Alternate Universe. Also there are no reasons to travel to another Universe other than to cause havoc. |
8,335 | In *Fringe*, there is the "Over Here" universe and the "Over there" universe that the characters interact with.
Why do only these two universes exist? Dr. Bishop mentioned that there were an unlimited number of universes existing at the same time.
I thought it was because it was the other universe that Walter went into that caused all the Fringe incidents, but in Walters experiments, he created a wall that only looked into the other universe, not any of the other universes.
Why are these two universes so important and not all the others? | 2011/12/30 | [
"https://scifi.stackexchange.com/questions/8335",
"https://scifi.stackexchange.com",
"https://scifi.stackexchange.com/users/1109/"
] | The universes are now connected because of the first cross over by Walter, so that's why it's possible to cross over between them in the present (although it continues not being easy for "normal people")
I think that Walter first created the window to that universe by chance, and the connection only intensified once he crossed over to save Peter. | To expand upon @Juan Manuel's answer a bit:
Walter originally built a device that could view other parallel universes, based on the Fringe universe's version of the many worlds theory. He used that device to watch alternate versions of himself try to solve the problem of Peter's fatal disease, something that he was unable to do in time. Walter found many such universes, none of them sucessfully curing Peter. He was focused in on one particular world where the alternate-him was close to solving the problem when things went sideways.
He just happened to see Walternate's experiment succeed, at the same moment that Observer September distracted Walternate, causing him to miss the result. Walter then decided that he needed to actually *go* to that other universe and save Peter. (Fully intending, I believe, to return Peter when he was done.) That's when Walter built the actual bridge device to travel to that universe and retrieve Peter, cure him, and return him.
When he finally went through with his plan, the end result was that Peter stayed in our world, and now there was an imbalance between the two worlds. That tied those two specific universes together in a way that other universes were not. Walter closed the bridge, but it was still "there" in some sense that the two universes were connected and "moving together".
In theory, Walter's bridge device could take someone to any other universe, assuming they were able to "find" it and calibrate the machine correctly. It's simply that our universe and the prime-universe were the easiest to bridge (having been done once), and there was little incentive for any anyone from either universe to find a third one. |
8,335 | In *Fringe*, there is the "Over Here" universe and the "Over there" universe that the characters interact with.
Why do only these two universes exist? Dr. Bishop mentioned that there were an unlimited number of universes existing at the same time.
I thought it was because it was the other universe that Walter went into that caused all the Fringe incidents, but in Walters experiments, he created a wall that only looked into the other universe, not any of the other universes.
Why are these two universes so important and not all the others? | 2011/12/30 | [
"https://scifi.stackexchange.com/questions/8335",
"https://scifi.stackexchange.com",
"https://scifi.stackexchange.com/users/1109/"
] | Both Nina and Bell indicate in the Second season that the two Universes are moving towards each other ever since Walter first Bridged the worlds. Hence the snow-globe collision metaphor. Since then travel between those Universes would be easier than between "Over Here" and any other Alternate Universe. Also there are no reasons to travel to another Universe other than to cause havoc. | In the Season 3 finale,
>
> Peter influenced events in the future, and altered the past. He stated in that episode that, somehow, they *are* the First People - due to a semi-stable time loop, it was the Fringe teams that put the device in the past to be found during the course of the series.
>
>
>
That event linked (or possibly split) the two universes, as the machine exist in both universes. Bolivia only stole what they couldn't find on Over There.
As of mid-season 4,
>
> Peter now believes he's in a 3rd/4th universe.
>
>
>
**EDIT:** Events in the series after this answer was posted shows us that the second spoiler is false - he was incorrect. |
8,335 | In *Fringe*, there is the "Over Here" universe and the "Over there" universe that the characters interact with.
Why do only these two universes exist? Dr. Bishop mentioned that there were an unlimited number of universes existing at the same time.
I thought it was because it was the other universe that Walter went into that caused all the Fringe incidents, but in Walters experiments, he created a wall that only looked into the other universe, not any of the other universes.
Why are these two universes so important and not all the others? | 2011/12/30 | [
"https://scifi.stackexchange.com/questions/8335",
"https://scifi.stackexchange.com",
"https://scifi.stackexchange.com/users/1109/"
] | Both Nina and Bell indicate in the Second season that the two Universes are moving towards each other ever since Walter first Bridged the worlds. Hence the snow-globe collision metaphor. Since then travel between those Universes would be easier than between "Over Here" and any other Alternate Universe. Also there are no reasons to travel to another Universe other than to cause havoc. | To expand upon @Juan Manuel's answer a bit:
Walter originally built a device that could view other parallel universes, based on the Fringe universe's version of the many worlds theory. He used that device to watch alternate versions of himself try to solve the problem of Peter's fatal disease, something that he was unable to do in time. Walter found many such universes, none of them sucessfully curing Peter. He was focused in on one particular world where the alternate-him was close to solving the problem when things went sideways.
He just happened to see Walternate's experiment succeed, at the same moment that Observer September distracted Walternate, causing him to miss the result. Walter then decided that he needed to actually *go* to that other universe and save Peter. (Fully intending, I believe, to return Peter when he was done.) That's when Walter built the actual bridge device to travel to that universe and retrieve Peter, cure him, and return him.
When he finally went through with his plan, the end result was that Peter stayed in our world, and now there was an imbalance between the two worlds. That tied those two specific universes together in a way that other universes were not. Walter closed the bridge, but it was still "there" in some sense that the two universes were connected and "moving together".
In theory, Walter's bridge device could take someone to any other universe, assuming they were able to "find" it and calibrate the machine correctly. It's simply that our universe and the prime-universe were the easiest to bridge (having been done once), and there was little incentive for any anyone from either universe to find a third one. |
172,074 | I am currently locked inside of the apartment that I just moved into today. I noticed that the door knob was a bit loose when I first opened the door this morning and when I turned the knob from the outside, the knob wouldn’t turn on the inside.
Eventually I tried to leave my apt and as I turned the knob and pulled, I just pulled out the knob. Anyone know how I can open this knobless door?
All other tutorials and forums on the internet seem to be for a different type of door. Any help would be appreciated. Thank you in advance. This is the best picture I could take because the opening is so small and the camera would not focus properly on any shot at all more detailed.
 | 2019/08/25 | [
"https://diy.stackexchange.com/questions/172074",
"https://diy.stackexchange.com",
"https://diy.stackexchange.com/users/105384/"
] | Stick a slotted screwdriver into the square hole and turn it counterclockwise... | I believe a kitchen knife will work, if you do not have any screwdrivers in your apt by sticking the pointed end in the square hole and turning the mechanism. |
706 | Our client has several specification sheets in pdf format for many of their products. What is the best or easiest way for them to add a downloadable PDF to each product page. (Some PDFs fit many products).
UPDATE: I found a very useful extension for this <http://amasty.com/product-attachments.html> | 2013/02/12 | [
"https://magento.stackexchange.com/questions/706",
"https://magento.stackexchange.com",
"https://magento.stackexchange.com/users/5540/"
] | A simple way to do this, without much programming, is to take advantage of magento's product attributes. It's very simple to do the following -
1. add a product attribute called "spec\_sheets" and allow that attribute to used on the front end. Then add that attribute to the appropriate product attribute sets.
2. have your client FTP the pdf files to a directory under your magento install - say media/specs.
3. edit the product(s) where the spec sheets should be shown and enter the pdf file names.
4. Update the product view template to detect if the attribute has a value by getting it's value, $\_product->getSpecSheet(). If a file exists in media/specs directory with the same name as the attribute, display a link to the PDF on the product page.
If there are more than 1 PDF per product, then you can have the admin enter the filenames in a comma separated list and then use php to parse out the individual filenames. | you can use this extension for product pdf [Pdf Extension](http://www.magentocommerce.com/magento-connect/product-attachments-extension.html)
This extension allows assigning multiple pdf file to your product, pdf can be uploaded and then assign in product is very easy |
706 | Our client has several specification sheets in pdf format for many of their products. What is the best or easiest way for them to add a downloadable PDF to each product page. (Some PDFs fit many products).
UPDATE: I found a very useful extension for this <http://amasty.com/product-attachments.html> | 2013/02/12 | [
"https://magento.stackexchange.com/questions/706",
"https://magento.stackexchange.com",
"https://magento.stackexchange.com/users/5540/"
] | A simple way to do this, without much programming, is to take advantage of magento's product attributes. It's very simple to do the following -
1. add a product attribute called "spec\_sheets" and allow that attribute to used on the front end. Then add that attribute to the appropriate product attribute sets.
2. have your client FTP the pdf files to a directory under your magento install - say media/specs.
3. edit the product(s) where the spec sheets should be shown and enter the pdf file names.
4. Update the product view template to detect if the attribute has a value by getting it's value, $\_product->getSpecSheet(). If a file exists in media/specs directory with the same name as the attribute, display a link to the PDF on the product page.
If there are more than 1 PDF per product, then you can have the admin enter the filenames in a comma separated list and then use php to parse out the individual filenames. | [Here's MagDoc Module](http://www.magentocommerce.com/magento-connect/sp-magdoc-8372.html) which helps to manage your PDF or any other types of file on Scribd and display that document on browse by adding few codes. Hope this helps. |
706 | Our client has several specification sheets in pdf format for many of their products. What is the best or easiest way for them to add a downloadable PDF to each product page. (Some PDFs fit many products).
UPDATE: I found a very useful extension for this <http://amasty.com/product-attachments.html> | 2013/02/12 | [
"https://magento.stackexchange.com/questions/706",
"https://magento.stackexchange.com",
"https://magento.stackexchange.com/users/5540/"
] | you can use this extension for product pdf [Pdf Extension](http://www.magentocommerce.com/magento-connect/product-attachments-extension.html)
This extension allows assigning multiple pdf file to your product, pdf can be uploaded and then assign in product is very easy | Another possibility is to use an extension which does exactly what you want to do.
There exists a free extension for this purpose:
<http://www.magentocommerce.com/magento-connect/pdf-for-every-product-8631.html>
Another one which is free for up to 1000 products is this one:
<http://www.magentocommerce.com/magento-connect/pdf-for-every-product-8631.html> |
706 | Our client has several specification sheets in pdf format for many of their products. What is the best or easiest way for them to add a downloadable PDF to each product page. (Some PDFs fit many products).
UPDATE: I found a very useful extension for this <http://amasty.com/product-attachments.html> | 2013/02/12 | [
"https://magento.stackexchange.com/questions/706",
"https://magento.stackexchange.com",
"https://magento.stackexchange.com/users/5540/"
] | A simple way to do this, without much programming, is to take advantage of magento's product attributes. It's very simple to do the following -
1. add a product attribute called "spec\_sheets" and allow that attribute to used on the front end. Then add that attribute to the appropriate product attribute sets.
2. have your client FTP the pdf files to a directory under your magento install - say media/specs.
3. edit the product(s) where the spec sheets should be shown and enter the pdf file names.
4. Update the product view template to detect if the attribute has a value by getting it's value, $\_product->getSpecSheet(). If a file exists in media/specs directory with the same name as the attribute, display a link to the PDF on the product page.
If there are more than 1 PDF per product, then you can have the admin enter the filenames in a comma separated list and then use php to parse out the individual filenames. | Another possibility is to use an extension which does exactly what you want to do.
There exists a free extension for this purpose:
<http://www.magentocommerce.com/magento-connect/pdf-for-every-product-8631.html>
Another one which is free for up to 1000 products is this one:
<http://www.magentocommerce.com/magento-connect/pdf-for-every-product-8631.html> |
706 | Our client has several specification sheets in pdf format for many of their products. What is the best or easiest way for them to add a downloadable PDF to each product page. (Some PDFs fit many products).
UPDATE: I found a very useful extension for this <http://amasty.com/product-attachments.html> | 2013/02/12 | [
"https://magento.stackexchange.com/questions/706",
"https://magento.stackexchange.com",
"https://magento.stackexchange.com/users/5540/"
] | you can use this extension for product pdf [Pdf Extension](http://www.magentocommerce.com/magento-connect/product-attachments-extension.html)
This extension allows assigning multiple pdf file to your product, pdf can be uploaded and then assign in product is very easy | [Here's MagDoc Module](http://www.magentocommerce.com/magento-connect/sp-magdoc-8372.html) which helps to manage your PDF or any other types of file on Scribd and display that document on browse by adding few codes. Hope this helps. |
55,463 | I have defined multiple signatures in Gmail, but want to delete some of them.
How do I do it? I have figured out how to blank them out, but want to actually delete them so that they don't get selected by accident. | 2014/02/03 | [
"https://webapps.stackexchange.com/questions/55463",
"https://webapps.stackexchange.com",
"https://webapps.stackexchange.com/users/58525/"
] | Blanking the field out is the only way and gives the result you are looking for. You can only have one signature per email address; not sure what you mean by selecting one accidently. | I tried to remove an old signature in my Gmail settings and can confirm there is no simple way to delete a signature. I think your best bet is to just clear out the old signature or select the No Signature option. Not ideal at all. |
55,463 | I have defined multiple signatures in Gmail, but want to delete some of them.
How do I do it? I have figured out how to blank them out, but want to actually delete them so that they don't get selected by accident. | 2014/02/03 | [
"https://webapps.stackexchange.com/questions/55463",
"https://webapps.stackexchange.com",
"https://webapps.stackexchange.com/users/58525/"
] | Blanking the field out is the only way and gives the result you are looking for. You can only have one signature per email address; not sure what you mean by selecting one accidently. | To remove the signature from Gmail you have to follow some steps.
1. First click on settings on the top right corner of your Gmail page.
2. Then click on the lab tab after clicking to the lab tab you find signature tweaks and enable that option by selecting the radio button.
3. Then click on the save changes buttons to save the changes made to the lab setting.
By the above process you can remove the signature from Gmail. |
55,463 | I have defined multiple signatures in Gmail, but want to delete some of them.
How do I do it? I have figured out how to blank them out, but want to actually delete them so that they don't get selected by accident. | 2014/02/03 | [
"https://webapps.stackexchange.com/questions/55463",
"https://webapps.stackexchange.com",
"https://webapps.stackexchange.com/users/58525/"
] | Blanking the field out is the only way and gives the result you are looking for. You can only have one signature per email address; not sure what you mean by selecting one accidently. | This seems to vary with different versions of Gmail. None of the answers I found were very helpful.
To delete a signature or change default do the following:
1. Click the cog on top right of mail screen and select *Settings*
2. Select the *Accounts and Import* tab
3. Alongside *Send email as:* you will find current signatures. You can delete, edit and change default here. |
252,226 | I'm trying to convert my lantern torchlight into a LED one, using a COB 10 Watts LED.
The LED look something like this, although won't be the exact one.
[](https://i.stack.imgur.com/y1Y4Q.jpg)
Is this heatsink suitable for a 10W LED? I found it in my storeroom, most probably scrapped it from my old CPU..
It's 9CM in diameter and around 1.5CM thick. If this can be used, can it be used without a cooling fan? Since the battery will be running on batteries, I'm trying to save as much power as possible.
And do you guys have any suggestions on how to mount the LED onto the heatsink? I'm thinking of drilling two holes then mount it on using bolts and nuts. It'll be great if I can just use thermal glue to glue it on, but I'm not sure whether it'll hold..
[](https://i.stack.imgur.com/93pY8.jpg)
[](https://i.stack.imgur.com/pmIBI.jpg) | 2016/08/14 | [
"https://electronics.stackexchange.com/questions/252226",
"https://electronics.stackexchange.com",
"https://electronics.stackexchange.com/users/71719/"
] | The usual source is TIA/EIA-568, which also describes the cat5e and cat6
cables used for Ethernet. I believe normal house wiring is cat3 under
that standard.
I'm not sure 'PE' (does that mean polyethylene?) is a specified insulator or sheathing material, though. There are both PVC and other (plenum-rated) sheathing materials for cat5, so the standard is unlikely to be very specific. | PE is resistant to UV, PVC isn't (or rather PE is *more* resistant to UV than PVC). Therefore PE is used outdoors.
PE, though, is more expensive than PVC, so PVC is chosen for indoors.
Yes, you can use PE indoors, but at a cost (so why would you?). You can't, though, (or shouldn't) use PVC outdoors since it degrades over time. |
25,263,388 | I am using following control to design a wizard in JQuery:
<http://techlaboratory.net/smartwizard/documentation>
By Default it shows three buttons (properties) labelNext, labelPrevious, labelFinish
As per requirement I would like to add another button So we can have buttons like
Previous, Next, Save, Save & Publish.
I see no option to add custom button
I want new button as below:
Cheers! | 2014/08/12 | [
"https://Stackoverflow.com/questions/25263388",
"https://Stackoverflow.com",
"https://Stackoverflow.com/users/2739418/"
] | Download bellow zip file and use that js and css
[Download Zip](http://www.files.com/shared/53ea0420db4fd/SmartWizard.zip) | The latest version have option to add more button to the toolbar. Here is the example [Smart Wizard: Demo](http://techlaboratory.net/smartwizard/demo/basic) and the [Smart Wizard: Documentaion](http://techlaboratory.net/smartwizard/documentation#paramdesc) |
5,949 | I am looking for a framework/solution for authentication/ user-login management/ security in java web application that can make the naive developer's job easier/faster and make the application relatively more secured against potential threats.
---
P.S. : I'm using JSF 2.0 as the front-end development framework in my web application. | 2011/08/04 | [
"https://security.stackexchange.com/questions/5949",
"https://security.stackexchange.com",
"https://security.stackexchange.com/users/10305/"
] | Check out [OWASP](https://www.owasp.org/)'s [ESAPI (Enterprise Security API)](https://www.owasp.org/index.php/Esapi).
>
> ESAPI (The OWASP Enterprise Security API) is a free, open source, web application security control library that makes it easier for programmers to write lower-risk applications. The ESAPI libraries are designed to make it easier for programmers to retrofit security into existing applications. The ESAPI libraries also serve as a solid foundation for new development.
>
>
>
While it is ported to several languages and frameworks, it started as a Java EE project. It's a very large and flexible framework, should meet most of your needs.
---
And as far as authentication and user management goes, *strongly* consider using OpenID (or something like that), so you dont have to manage it at all. Depending on your usecases and userbase, this can be a huge benefit, to you AND your users. | If you still have the freedom to choose the web application framework you are using, I can recommend web2py. It has built-in support for authentication, log-in management, and many other security needs. It was designed right from the get-go to make many security problems (e.g., XSS, SQL injection, session management attacks, etc.) nearly impossible. And, as a bonus, it is beautiful, clean, and easy-to-learn.
web2py: Give it a try. |
1,173,289 | I am attempting to get the following network to work:
BT Homehub (primary router, upstairs) <--- powerline (TP Link AV1200) -- -- powerline (TP Link AV1200) --> Sky SR102 (secondary router, DHCP off - downstairs)
I want the Sky router to broadcast wifi signal downstairs as a sort of "repeater." I have followed these steps:
* Change Sky IP to 192.168.8.10 (<https://sites.google.com/site/easylinuxtipsproject/second-router>)
* Switch DHCP off
* Connect Sky router to powerline downstairs via Ethernet
The SSIDs for both networks are not the same.The primary router's range is 192.168.1.X
Problem: Although the network connects and all powerline adapter lights are green, I am experiencing frequent drops in connection downstairs to the point where I either have to reconnect to the Sky's network or select primary router's network to connect. Speedtest shows the same connection speed as before. Changing the channels (6 and 11, 7 and 11, 11 and 11 - 1 is too crowded in my vicinity) didn't help at all. I have tried to set a constant ping to the primary router (read somewhere it could help with the drops) but it didn't change anything either.
I am also unable to reach the secondary router either by its new IP or factory IP address so I can't change its settings at all.
Also not all of my devices will connect to the secondary router network.
Any ideas??? It feels like the two networks are cancelling each other out, but I don't understand why, I have tried to google the issue but came up emptyhanded.
EDIT: The default IP range of the primary router is 192.168.1.64 - 192.168.1.253
Thanks | 2017/01/30 | [
"https://superuser.com/questions/1173289",
"https://superuser.com",
"https://superuser.com/users/691753/"
] | A lack of GPU does not make your computer an Ultrabook.
An Ultrabook is a marketing term applied to computers with a particular size, shape, and weight, mostly.
When you got your laptop wet it may have damaged components inside the laptop. If the GPU itself is exhibiting unexpected/undesired behavior the damage is actually on your entire CPU die (the "chip") because that is where the GPU lives on your computer.
Based on your description of the symptoms, I'm guessing you're experiencing software issues not hardware. I may be wrong, but the delay between the damage and this issue and the nature of the issue seems to point in this direction.
What you should do is reinstall the operating system and get the latest drivers for your device. If things work OK at that point, then the issue was indeed just software. If you're still getting these issues with the integrated graphics not working, then the issue may indeed be hardware-related, and at that point it is likely that the cost to repair (replacing CPU and mainboard, at least) is higher than the actual value of the laptop. | You rare getting graphics on the display after booting into 'Safe Mode' because safe mode loads a very basic driver and does not enable your HD graphics whether on a gpu or MB.
Sometimes something can go wrong with particular circuits in hardware devices (ie: Capacitors and voltage regulators can start to fail or some circuit paths shorted or non-functioning.) and the hardware chip or circuit can partially work. If Loading the HD graphics driver did not solve your problem, then starting over with a fresh OS install can eliminate the possibility of software related issues but if Ubuntu could not find the graphic then I would surmise a guess that a fresh Windows install would produce similar results
TL:DR version. Sounds like some kind of hardware issue and those are difficult to track down on laptops. |
131,805 | Some islands are called isle like "Isle of Man", "Isle of Tortuga" and the "British Isles". Other islands are called island, like "Island of Malta" or "Island of Cyprus".
What is the difference between the words?
How to know if a land mass confined by water is called an isle or an island? | 2013/10/16 | [
"https://english.stackexchange.com/questions/131805",
"https://english.stackexchange.com",
"https://english.stackexchange.com/users/20436/"
] | In practice there is no difference, they can be used interchangeably, but *isle* is archaic. Anything called *isle* can also be referred to as an island.
I had thought that *isle* was just an archaic version of *island*, but it turns out the words are actually not related:
>
> [island](http://www.etymonline.com/index.php?term=island&allowed_in_frame=0) (n.)
>
>
> 1590s, earlier yland (c.1300), from Old English igland "island," from ieg "island" (from Proto-Germanic \*aujo "thing on the water," from PIE \*akwa- "water;" see aqua-) + land "land." Spelling modified 15c. **by association with similar but unrelated isle**. An Old English cognate was ealand "river-land, watered place, meadow by a river." In place names, Old English ieg is often used of "slightly raised dry ground offering settlement sites in areas surrounded by marsh or subject to flooding" [Cambridge Dictionary of English Place-Names]. Related: Islander.
>
>
> [isle](http://www.etymonline.com/index.php?term=isle) (n.)
>
>
> late 13c., from Old French ile, earlier isle, from Latin insula "island," of uncertain origin, perhaps (as the Ancients guessed) from in salo "(that which is) in the sea," from ablative of salum "the open sea." The -s- was restored first in French, then in English in the late 1500s.
>
>
> | There is no difference in the words' meanings, they both denote a landmass surrounded by water.
The [definition](http://www.thefreedictionary.com/isle) from one of the dictionaries sums it up nicely about "isle", I think:
>
> Poetic except when cap. and part of place name; an island, esp a small one
>
>
>
So "isle" has the same meaning, just more poetic (it is a monosyllabic word), more often used with small islands. As for geographic names - they were named like that at some time, so someone chose "isle" over "island" while naming them. |
131,805 | Some islands are called isle like "Isle of Man", "Isle of Tortuga" and the "British Isles". Other islands are called island, like "Island of Malta" or "Island of Cyprus".
What is the difference between the words?
How to know if a land mass confined by water is called an isle or an island? | 2013/10/16 | [
"https://english.stackexchange.com/questions/131805",
"https://english.stackexchange.com",
"https://english.stackexchange.com/users/20436/"
] | In practice there is no difference, they can be used interchangeably, but *isle* is archaic. Anything called *isle* can also be referred to as an island.
I had thought that *isle* was just an archaic version of *island*, but it turns out the words are actually not related:
>
> [island](http://www.etymonline.com/index.php?term=island&allowed_in_frame=0) (n.)
>
>
> 1590s, earlier yland (c.1300), from Old English igland "island," from ieg "island" (from Proto-Germanic \*aujo "thing on the water," from PIE \*akwa- "water;" see aqua-) + land "land." Spelling modified 15c. **by association with similar but unrelated isle**. An Old English cognate was ealand "river-land, watered place, meadow by a river." In place names, Old English ieg is often used of "slightly raised dry ground offering settlement sites in areas surrounded by marsh or subject to flooding" [Cambridge Dictionary of English Place-Names]. Related: Islander.
>
>
> [isle](http://www.etymonline.com/index.php?term=isle) (n.)
>
>
> late 13c., from Old French ile, earlier isle, from Latin insula "island," of uncertain origin, perhaps (as the Ancients guessed) from in salo "(that which is) in the sea," from ablative of salum "the open sea." The -s- was restored first in French, then in English in the late 1500s.
>
>
> | In modern everyday use 'Isle' tends to be included in the name by which the place is known, such as the ones you mention plus the Isle of Skye, Isle of Mull, Isle of Wight etc. (No one says simply 'Wight' to refer to the Isle of Wight, nor 'Man' to refer to the Isle of Man.) Though you may hear the term 'island of Malta', or island of Cyprus', which are quite correct since both are islands - the word 'island' does not usually form part of the place name, by which they are called. One would normally say simply 'Malta' or 'Cyprus'. You would only use the word 'island' if you were wanting to stress the fact that they were islands. which is why I have not capitalised the i. |
131,805 | Some islands are called isle like "Isle of Man", "Isle of Tortuga" and the "British Isles". Other islands are called island, like "Island of Malta" or "Island of Cyprus".
What is the difference between the words?
How to know if a land mass confined by water is called an isle or an island? | 2013/10/16 | [
"https://english.stackexchange.com/questions/131805",
"https://english.stackexchange.com",
"https://english.stackexchange.com/users/20436/"
] | In modern everyday use 'Isle' tends to be included in the name by which the place is known, such as the ones you mention plus the Isle of Skye, Isle of Mull, Isle of Wight etc. (No one says simply 'Wight' to refer to the Isle of Wight, nor 'Man' to refer to the Isle of Man.) Though you may hear the term 'island of Malta', or island of Cyprus', which are quite correct since both are islands - the word 'island' does not usually form part of the place name, by which they are called. One would normally say simply 'Malta' or 'Cyprus'. You would only use the word 'island' if you were wanting to stress the fact that they were islands. which is why I have not capitalised the i. | There is no difference in the words' meanings, they both denote a landmass surrounded by water.
The [definition](http://www.thefreedictionary.com/isle) from one of the dictionaries sums it up nicely about "isle", I think:
>
> Poetic except when cap. and part of place name; an island, esp a small one
>
>
>
So "isle" has the same meaning, just more poetic (it is a monosyllabic word), more often used with small islands. As for geographic names - they were named like that at some time, so someone chose "isle" over "island" while naming them. |
3,961 | When I was a student (in the 1970s) I was taught linear algebra as an "adjunct" to "engineering mathematics" such as differential equations. That was during my sophomore year, which seems a bit late, but those were the days when "calculus" was all the rage.
Nowadays, the application emphasis is on information technology, which stores information in matrices, strings, and vectors. Given this emphasis should linear algebra be taught earlier, concurrently with computer science? Would that mean making it "simultaneous" with first year calculus or even pre-calculus? | 2014/07/10 | [
"https://matheducators.stackexchange.com/questions/3961",
"https://matheducators.stackexchange.com",
"https://matheducators.stackexchange.com/users/1333/"
] | My personal opinion. Anytime is a good time to teach linear algebra. I'd like to see at least two courses in the curriculum. Ok, more accurately:
1. **elementary matrix theory:** solving systems, matrix math, determinants, routine computations of all sorts. Very limited proof emphasis. Here we are merely rounding out a computational core to give better tools to later calculus and other courses. This could be taught before calculus, in parallel with precalculus if need be. I would hope to include some appreciation of spanning and linear independence here. We'd like to use these terms intelligently in other courses before they hit linear algebra. Applications abound in this course. For example, [Lay's Linear Algebra](http://rads.stackoverflow.com/amzn/click/0321385179) would be ideal.
2. **linear algebra:** focus on proofs and abstraction. Includes abstract vector spaces, subspace and basis theorems. Either this course comes after the introduction to proofs course and gets to the Jordan form, or, the topics covered are narrowed considerably and the course is used as the introduction to formal proofs course. For the non-introductory to proofs version, you might use [Insel, Spence and Friedberg](http://rads.stackoverflow.com/amzn/click/0130084514)
There are good reasons for making this demarcation in courses. The elementary matrix theory course is really worthwhile for almost every technical major and if it was earlier in the degree plans then many sections could be offered at a larger school making scheduling easy for the student. On the other hand, linear algebra proper is really just a course for math majors and it is an absolute drudgery to try to teach proofs to engineers. I speak with considerable experience. | The way "programs store data in arrays" has next to nothing in common with linear algebra. Don't mix them up, the superficial similarities are confusing enough as is.
For a nice look at what linear algebra is really about check out Treil's ["Linear Algebra done Wrong"](http://www.math.brown.edu/~treil/papers/LADW/LADW.html). |
9,472,227 | Can I programmatically create a keyboard Shortcut to my add-in's in Revit? | 2012/02/27 | [
"https://Stackoverflow.com/questions/9472227",
"https://Stackoverflow.com",
"https://Stackoverflow.com/users/228160/"
] | Manualy, you can by adding a line to KeyboardShortcuts.txt located in the Revit Program folder. Look at these posts for more explanations: <http://thebuildingcoder.typepad.com/blog/2009/04/addin-keyboard-shortcut.html> and <http://blog.rodhowarth.com/2009/04/how-to-create-keyboard-shortcuts-to.html>
But as this file is stored in Program Files, you will not be able to write to it without being logged as administrator (Windows Vista, Windows 7). And Revit can lock it also. | According to the [Building Coder](http://thebuildingcoder.typepad.com/blog/2012/03/revit-2013-and-its-api.html) you should be able to do this through the API as of Revit 2013. |
126,580 | I want to create footer links inside my master page, and I was wondering what's the best approach to achieve this, do I create a SharePoint List to store my lists and embed it as a list and change its look using `JSLink`?
What are the pros and cons about this approach? Or do I use server side code and use caching to create this section? Any recommendations? | 2015/01/05 | [
"https://sharepoint.stackexchange.com/questions/126580",
"https://sharepoint.stackexchange.com",
"https://sharepoint.stackexchange.com/users/37240/"
] | I would go for a User control with server side code. The UC can read from a list you (or the user control itself) creates and then create HTML from that result. You can then style the HTML with CSS if needed
I would use HttpCache or similar to cache the final HTML for as long time as you think is viable for your use case (note that an IISRESET will clear the cache) to get great performance and low stress on the server.
The user control can then be added to the master page directly or through a delegate control depending on wether or not you have a custom master page. | Since you are using SharePoint 2013, you can either use JSOM or REST API to read the data.
This is happening on the client side, and it will be easier to add it to respective DOM elements (or create new elements).
JSLink is a good option, but implementation will take more time. I prefer REST as it's much easier to implement and performs better. |
10,710 | Richard Dawkins has claimed many times in public speeches, especially in reference to the documentary “Expelled”, that documentary filmmakers use the expression “Lord Privy Seal” in a disparaging manner to describe the amateur’s tendency to illustrate words or sentences spoken by the narrator with a straight picture depicting said concept.
However, a Google search for the term only reveals references to the English nobility title (which the saying is supposedly derived from) and to Richard Dawkins making this claim. Even the [Wikipedia entry](http://en.wikipedia.org/wiki/Lord_Privy_Seal_%28term%29#.22Lord_Privy_Seal.22) refers to Richard Dawkins. One would think that if it’s a well-known expression in the trade, surely some documentary filmmaking fansite, glossary or handbook would define the term, and Google should be able to find such a page which predates Richard Dawkins.
Is this term real, or did Richard Dawkins (or someone he knows) make it up? | 2012/09/02 | [
"https://skeptics.stackexchange.com/questions/10710",
"https://skeptics.stackexchange.com",
"https://skeptics.stackexchange.com/users/121/"
] | No, Richard Dawkins did not invent the term.
"Lord Privy Seal" is a reference to [a parody of the practice](http://www.youtube.com/watch?v=AVlfvdH7qwY&NR=1) performed by David Frost, on The Frost Report in 1966.
Since then, the trope has been known by other terms, such as [B Roll Rebus](http://tvtropes.org/pmwiki/pmwiki.php/Main/BRollRebus).
Webster's Online Dictionary [acknowledges this usage](http://www.websters-online-dictionary.org/definitions/lord+privy+seal) and the etymology:
>
> The term "Lord Privy Seal" (as in "not bad, but it's a bit Lord Privy Seal") is used in the British television industry as shorthand for associating pictures too closely and literally with every element of the accompanying spoken script
>
>
>
Webster's seems to rely on the memoirs of BBC insider, John Sergeant, *[Give me Ten Seconds](http://www.amazon.co.uk/Give-Ten-Seconds-John-Sergeant/dp/0330484907)*, for the usage. | Oddthinking's pointer to David Frost in 1966 shows the use in film making, but the over-literal interpretation of the title of position (in fact a minister without portfolio who had historically looked after the monarch's private seal) was promoted by Edward Heath (Lord Privy Seal 1961-1963), which [he attributed to Ernest Bevin](http://www.portcullis.parliament.uk/DServe/dserve.exe?dsqIni=Dserve.ini&dsqApp=Archive&dsqDb=Persons&dsqSearch=Code==%27649%27&dsqCmd=Show.tcl) (Lord Privy Seal 1951), saying he
>
> was neither a lord, nor a privy nor a seal
>
>
>
This was repeated by the British Ambassador in Washington D.C. and reported in US local newspapers, such as the [Florence Times, Alabama on December 18 1961](http://news.google.com/newspapers?nid=1842&dat=19611218&id=Pv0rAAAAIBAJ&sjid=ssYEAAAAIBAJ&pg=6166,5955715). |
314,325 | I'm looking for a simple **but direct** way to transfer a file of any kind and any size between two people. If possible, having only a web browser, without having the file stored on a third machine meanwhile.
I wish to do it **without** requiring the end users to connect to a third server, because that way the data will flow through the machine `xyz.com`, possibly slowing down the transfer, and posing security risks.
I would like to avoid setting up a whole FTP server just for occasional file transfers. So far I have discovered [JetBytes](http://jetbytes.com/), [Click2Copy](http://click2copy.com/) and [PipeBytes](http://host03.pipebytes.com/). Those web services should make the transfer easy. However the traffic goes through their servers so they are no good to what I want.
I want the transfer to be direct between the client and me. **Encryption would be a nice additional feature.**
I know that doing so I have to open one port on my computer, and configure a bit port redirection on my router. **However, NAT traversal would be nice addition, too.**
My question is:
**Is there a simple way for one single end-to-end direct file transfer between two computer, avoiding third parties?** (if possible, with encryption and NAT traversal) | 2011/07/24 | [
"https://superuser.com/questions/314325",
"https://superuser.com",
"https://superuser.com/users/50883/"
] | If your running Linux / unix ssh is a secure way to transmit files in a client server model. port forwards needed on incoming connections if behind NAT though. | A webserver that can do [UPnP NAT traversal](http://en.wikipedia.org/wiki/NAT_traversal) would work, the receiver would only needs a web browser. As a bonus encryption is easy with a web server, just use https.
Here is one example (payware 99USD) [RaidenHTTPD](http://www.raidenhttpd.com/en/) |
314,325 | I'm looking for a simple **but direct** way to transfer a file of any kind and any size between two people. If possible, having only a web browser, without having the file stored on a third machine meanwhile.
I wish to do it **without** requiring the end users to connect to a third server, because that way the data will flow through the machine `xyz.com`, possibly slowing down the transfer, and posing security risks.
I would like to avoid setting up a whole FTP server just for occasional file transfers. So far I have discovered [JetBytes](http://jetbytes.com/), [Click2Copy](http://click2copy.com/) and [PipeBytes](http://host03.pipebytes.com/). Those web services should make the transfer easy. However the traffic goes through their servers so they are no good to what I want.
I want the transfer to be direct between the client and me. **Encryption would be a nice additional feature.**
I know that doing so I have to open one port on my computer, and configure a bit port redirection on my router. **However, NAT traversal would be nice addition, too.**
My question is:
**Is there a simple way for one single end-to-end direct file transfer between two computer, avoiding third parties?** (if possible, with encryption and NAT traversal) | 2011/07/24 | [
"https://superuser.com/questions/314325",
"https://superuser.com",
"https://superuser.com/users/50883/"
] | The dirtiest way if you use \*nix is to use netcat (`nc`) to cat the file to the remote host. But if you want encryption, you might as well use SCP/SSH.
You have to realize that if either party is behind a NAT and you don't want to setup port forwarding, then it's impossible to make a direct connection without connecting to a third-party server first. The server does not necessarily have to relay the traffic (see <http://en.wikipedia.org/wiki/UDP_hole_punching>) and most of them don't as bandwidth is costly.
For example, Skype will try to use many NAT traversal methods to establish a direct connection before falling back to relaying traffic through their super nodes. (Skype is a very P2P network.)
As for the account problem. I guess it's unavoidable. All methods will require some kind of configuration or setup which are usually harder than registering an account. | Bit torrent sync does synchronize folders over the web. Files are encrypted also.
Check it out.
<http://www.bittorrent.com/sync> |
314,325 | I'm looking for a simple **but direct** way to transfer a file of any kind and any size between two people. If possible, having only a web browser, without having the file stored on a third machine meanwhile.
I wish to do it **without** requiring the end users to connect to a third server, because that way the data will flow through the machine `xyz.com`, possibly slowing down the transfer, and posing security risks.
I would like to avoid setting up a whole FTP server just for occasional file transfers. So far I have discovered [JetBytes](http://jetbytes.com/), [Click2Copy](http://click2copy.com/) and [PipeBytes](http://host03.pipebytes.com/). Those web services should make the transfer easy. However the traffic goes through their servers so they are no good to what I want.
I want the transfer to be direct between the client and me. **Encryption would be a nice additional feature.**
I know that doing so I have to open one port on my computer, and configure a bit port redirection on my router. **However, NAT traversal would be nice addition, too.**
My question is:
**Is there a simple way for one single end-to-end direct file transfer between two computer, avoiding third parties?** (if possible, with encryption and NAT traversal) | 2011/07/24 | [
"https://superuser.com/questions/314325",
"https://superuser.com",
"https://superuser.com/users/50883/"
] | The dirtiest way if you use \*nix is to use netcat (`nc`) to cat the file to the remote host. But if you want encryption, you might as well use SCP/SSH.
You have to realize that if either party is behind a NAT and you don't want to setup port forwarding, then it's impossible to make a direct connection without connecting to a third-party server first. The server does not necessarily have to relay the traffic (see <http://en.wikipedia.org/wiki/UDP_hole_punching>) and most of them don't as bandwidth is costly.
For example, Skype will try to use many NAT traversal methods to establish a direct connection before falling back to relaying traffic through their super nodes. (Skype is a very P2P network.)
As for the account problem. I guess it's unavoidable. All methods will require some kind of configuration or setup which are usually harder than registering an account. | If your running Linux / unix ssh is a secure way to transmit files in a client server model. port forwards needed on incoming connections if behind NAT though. |
314,325 | I'm looking for a simple **but direct** way to transfer a file of any kind and any size between two people. If possible, having only a web browser, without having the file stored on a third machine meanwhile.
I wish to do it **without** requiring the end users to connect to a third server, because that way the data will flow through the machine `xyz.com`, possibly slowing down the transfer, and posing security risks.
I would like to avoid setting up a whole FTP server just for occasional file transfers. So far I have discovered [JetBytes](http://jetbytes.com/), [Click2Copy](http://click2copy.com/) and [PipeBytes](http://host03.pipebytes.com/). Those web services should make the transfer easy. However the traffic goes through their servers so they are no good to what I want.
I want the transfer to be direct between the client and me. **Encryption would be a nice additional feature.**
I know that doing so I have to open one port on my computer, and configure a bit port redirection on my router. **However, NAT traversal would be nice addition, too.**
My question is:
**Is there a simple way for one single end-to-end direct file transfer between two computer, avoiding third parties?** (if possible, with encryption and NAT traversal) | 2011/07/24 | [
"https://superuser.com/questions/314325",
"https://superuser.com",
"https://superuser.com/users/50883/"
] | The dirtiest way if you use \*nix is to use netcat (`nc`) to cat the file to the remote host. But if you want encryption, you might as well use SCP/SSH.
You have to realize that if either party is behind a NAT and you don't want to setup port forwarding, then it's impossible to make a direct connection without connecting to a third-party server first. The server does not necessarily have to relay the traffic (see <http://en.wikipedia.org/wiki/UDP_hole_punching>) and most of them don't as bandwidth is costly.
For example, Skype will try to use many NAT traversal methods to establish a direct connection before falling back to relaying traffic through their super nodes. (Skype is a very P2P network.)
As for the account problem. I guess it's unavoidable. All methods will require some kind of configuration or setup which are usually harder than registering an account. | A webserver that can do [UPnP NAT traversal](http://en.wikipedia.org/wiki/NAT_traversal) would work, the receiver would only needs a web browser. As a bonus encryption is easy with a web server, just use https.
Here is one example (payware 99USD) [RaidenHTTPD](http://www.raidenhttpd.com/en/) |
314,325 | I'm looking for a simple **but direct** way to transfer a file of any kind and any size between two people. If possible, having only a web browser, without having the file stored on a third machine meanwhile.
I wish to do it **without** requiring the end users to connect to a third server, because that way the data will flow through the machine `xyz.com`, possibly slowing down the transfer, and posing security risks.
I would like to avoid setting up a whole FTP server just for occasional file transfers. So far I have discovered [JetBytes](http://jetbytes.com/), [Click2Copy](http://click2copy.com/) and [PipeBytes](http://host03.pipebytes.com/). Those web services should make the transfer easy. However the traffic goes through their servers so they are no good to what I want.
I want the transfer to be direct between the client and me. **Encryption would be a nice additional feature.**
I know that doing so I have to open one port on my computer, and configure a bit port redirection on my router. **However, NAT traversal would be nice addition, too.**
My question is:
**Is there a simple way for one single end-to-end direct file transfer between two computer, avoiding third parties?** (if possible, with encryption and NAT traversal) | 2011/07/24 | [
"https://superuser.com/questions/314325",
"https://superuser.com",
"https://superuser.com/users/50883/"
] | WebRTC-based solutions give what you need, in perhaps the simplest form. You do connect to a third-party website but that is only for getting the peers connected and not the file transfer part.
Example services:
<https://www.justbeamit.com/>
<https://www.sharedrop.io/>
EDIT: I understand this does not meet all the requirements of the OP but there is another, very usable solution: [Firefox Send](https://send.firefox.com/). Using this, you upload your file to a third-party server in an encrypted form. The service gives you a URL, which you can share with others. The URL also contains the key to decrypt the file. They can then download the file. The file is automatically deleted after a set number of downloads or after 24 hours. The server never sees the key and so cannot decrypt the file. The advantage in using a third-party server is that the sharing party and the downloading party do not need to be online simultaneously. | You may try out Folder Transfer from <http://www.foldertransfer.com>, which can direct transfer of a file between two computers on the Internet. It can fully meet your needs. |
314,325 | I'm looking for a simple **but direct** way to transfer a file of any kind and any size between two people. If possible, having only a web browser, without having the file stored on a third machine meanwhile.
I wish to do it **without** requiring the end users to connect to a third server, because that way the data will flow through the machine `xyz.com`, possibly slowing down the transfer, and posing security risks.
I would like to avoid setting up a whole FTP server just for occasional file transfers. So far I have discovered [JetBytes](http://jetbytes.com/), [Click2Copy](http://click2copy.com/) and [PipeBytes](http://host03.pipebytes.com/). Those web services should make the transfer easy. However the traffic goes through their servers so they are no good to what I want.
I want the transfer to be direct between the client and me. **Encryption would be a nice additional feature.**
I know that doing so I have to open one port on my computer, and configure a bit port redirection on my router. **However, NAT traversal would be nice addition, too.**
My question is:
**Is there a simple way for one single end-to-end direct file transfer between two computer, avoiding third parties?** (if possible, with encryption and NAT traversal) | 2011/07/24 | [
"https://superuser.com/questions/314325",
"https://superuser.com",
"https://superuser.com/users/50883/"
] | The dirtiest way if you use \*nix is to use netcat (`nc`) to cat the file to the remote host. But if you want encryption, you might as well use SCP/SSH.
You have to realize that if either party is behind a NAT and you don't want to setup port forwarding, then it's impossible to make a direct connection without connecting to a third-party server first. The server does not necessarily have to relay the traffic (see <http://en.wikipedia.org/wiki/UDP_hole_punching>) and most of them don't as bandwidth is costly.
For example, Skype will try to use many NAT traversal methods to establish a direct connection before falling back to relaying traffic through their super nodes. (Skype is a very P2P network.)
As for the account problem. I guess it's unavoidable. All methods will require some kind of configuration or setup which are usually harder than registering an account. | You may try out Folder Transfer from <http://www.foldertransfer.com>, which can direct transfer of a file between two computers on the Internet. It can fully meet your needs. |
129,368 | I have five applications residing on server(s). Some of these applications are socket (C/C++) based, others are web based (Java, PHP). I need to give licenses to these applications on the basis of the number of users that can access, the type of functionalities and type of users. What kind of business model should I use? I have a few in mind:
1. Create a java webservice that will be mounted on a license data, and all the servers will communicate with it when a user logins to any of the above applications.
2. Do a socket based server.
3. Mount a license file on each server and make each one communicate with its file individually and act as the license rules.
If you have other solutions please shoot. | 2012/01/10 | [
"https://softwareengineering.stackexchange.com/questions/129368",
"https://softwareengineering.stackexchange.com",
"https://softwareengineering.stackexchange.com/users/44828/"
] | **Use a local digitally signed license file encoding business rules**
I've split my answer to cover generally accepted requirements, a matching business strategy and the technical aspects of the problem.
**General requirements**
Few things annoy users more than having their work interrupted as a result of a license issue. To that end you want to have a system that:
* is resilient against network and hardware failure (no single point of failure)
* scales well (new servers and more users arrive as the business grows)
* is resilient against forgery of licenses
* warns administrators when they are approaching the limits of their license
* doesn't ever present a false positive (if unsure allow access is the rule for customer-friendly licensing behaviour)
to name but a few.
**Business strategy**
Your company will want total control over the license, otherwise the customer will manipulate the values to their advantage. However, the customer will not want your company looking over their shoulder and so the system will need to be self-contained on their site.
The customer will not want their entire system to fail if a license is unable to be verified. This obvious demand rules out a networked cental authentication approach because it could fail for a multitude of reasons (network, poor coding, power outage, hardware failure etc). While the central license authenticator is being repaired (could be days to get that done) the customer is unable to do anything - totally unacceptable.
With the above in mind, the strategy to keep your customer happy is to take a bit of a hit in terms of maintenance by using a local license file containing the rules for the given server.
**Technical implementation**
To achieve that goal, and minimise the hit, I would suggest that you will need to do the following:
1. Write a license configuration tool for your company. This file defines the user limit, allowed functions, and user types for each product in the form of a digitally signed license file issued by your company using a private key.
2. The servers must load the license file and verify the digital signature using your public key which is hosted on a well-known public key site ([pgp.mit.edu](http://pgp.mit.edu/)) or embedded directly in the code on startup or after maintenance
3. Each server verifies it's current user load, type and tasks against the signed license file as traffic occurs. Loading approaching the limit of the license should trigger an email or message to the system administrators.
4. Servers can update their license file in response to a socket-based PUT request that has a suitable digital signature (again verified by the remote key site). This will allow an automated script to provide license changes when one of your guys is on site providing maintenance. | Are you sure that you want to write this?
Have you looked into existing license control applications/services?
If the cost is not prohibitive, this sounds like a classic not-worth-inventing-here application. |
129,368 | I have five applications residing on server(s). Some of these applications are socket (C/C++) based, others are web based (Java, PHP). I need to give licenses to these applications on the basis of the number of users that can access, the type of functionalities and type of users. What kind of business model should I use? I have a few in mind:
1. Create a java webservice that will be mounted on a license data, and all the servers will communicate with it when a user logins to any of the above applications.
2. Do a socket based server.
3. Mount a license file on each server and make each one communicate with its file individually and act as the license rules.
If you have other solutions please shoot. | 2012/01/10 | [
"https://softwareengineering.stackexchange.com/questions/129368",
"https://softwareengineering.stackexchange.com",
"https://softwareengineering.stackexchange.com/users/44828/"
] | **Use a local digitally signed license file encoding business rules**
I've split my answer to cover generally accepted requirements, a matching business strategy and the technical aspects of the problem.
**General requirements**
Few things annoy users more than having their work interrupted as a result of a license issue. To that end you want to have a system that:
* is resilient against network and hardware failure (no single point of failure)
* scales well (new servers and more users arrive as the business grows)
* is resilient against forgery of licenses
* warns administrators when they are approaching the limits of their license
* doesn't ever present a false positive (if unsure allow access is the rule for customer-friendly licensing behaviour)
to name but a few.
**Business strategy**
Your company will want total control over the license, otherwise the customer will manipulate the values to their advantage. However, the customer will not want your company looking over their shoulder and so the system will need to be self-contained on their site.
The customer will not want their entire system to fail if a license is unable to be verified. This obvious demand rules out a networked cental authentication approach because it could fail for a multitude of reasons (network, poor coding, power outage, hardware failure etc). While the central license authenticator is being repaired (could be days to get that done) the customer is unable to do anything - totally unacceptable.
With the above in mind, the strategy to keep your customer happy is to take a bit of a hit in terms of maintenance by using a local license file containing the rules for the given server.
**Technical implementation**
To achieve that goal, and minimise the hit, I would suggest that you will need to do the following:
1. Write a license configuration tool for your company. This file defines the user limit, allowed functions, and user types for each product in the form of a digitally signed license file issued by your company using a private key.
2. The servers must load the license file and verify the digital signature using your public key which is hosted on a well-known public key site ([pgp.mit.edu](http://pgp.mit.edu/)) or embedded directly in the code on startup or after maintenance
3. Each server verifies it's current user load, type and tasks against the signed license file as traffic occurs. Loading approaching the limit of the license should trigger an email or message to the system administrators.
4. Servers can update their license file in response to a socket-based PUT request that has a suitable digital signature (again verified by the remote key site). This will allow an automated script to provide license changes when one of your guys is on site providing maintenance. | I think you should look at the [FlexLm](http://www.flexerasoftware.com/).
For awhile SUN was using it to provide distributed licence services for their products. |
5,478,904 | Hello
I want to create a 64bit application in c# and I wan't to use in it a dll created in C++ builder (32bit). But when I try to load the dll the application crashes. When built in 32bit it works. Is there a way to use this dll in a 64bit app? | 2011/03/29 | [
"https://Stackoverflow.com/questions/5478904",
"https://Stackoverflow.com",
"https://Stackoverflow.com/users/682823/"
] | No this is not possible. A process in Windows is either 32 or 64 bit and it can only load DLL's which match. Any attempt to load a DLL which does not match will fail and produce an error.
If you need to match 32 and 64 bit code you need to use multiple processes. In this case though I would just make the application 32 bit or the DLL 64 bit | You cannot load a 32-bit DLL into a 64-bit process on Windows.
I have never tried it myself, but you might be able to create a seperate 32-bit application that can run in a different process and act as a proxy for the DLL. Your application could then run 64-bit and communicate with the DLL with remote procedure calls over WCF.
If performance is a concern, then your best bet would be to rebuild the DLL in 64-bit, if possible. |
5,478,904 | Hello
I want to create a 64bit application in c# and I wan't to use in it a dll created in C++ builder (32bit). But when I try to load the dll the application crashes. When built in 32bit it works. Is there a way to use this dll in a 64bit app? | 2011/03/29 | [
"https://Stackoverflow.com/questions/5478904",
"https://Stackoverflow.com",
"https://Stackoverflow.com/users/682823/"
] | Do you want to build a 64-bit application, or you want to build an application that will run in a 64-bit environment? Your application can run perfectly fine in a 64-bit environment even when the target platform is x86. | You cannot load a 32-bit DLL into a 64-bit process on Windows.
I have never tried it myself, but you might be able to create a seperate 32-bit application that can run in a different process and act as a proxy for the DLL. Your application could then run 64-bit and communicate with the DLL with remote procedure calls over WCF.
If performance is a concern, then your best bet would be to rebuild the DLL in 64-bit, if possible. |
5,478,904 | Hello
I want to create a 64bit application in c# and I wan't to use in it a dll created in C++ builder (32bit). But when I try to load the dll the application crashes. When built in 32bit it works. Is there a way to use this dll in a 64bit app? | 2011/03/29 | [
"https://Stackoverflow.com/questions/5478904",
"https://Stackoverflow.com",
"https://Stackoverflow.com/users/682823/"
] | No this is not possible. A process in Windows is either 32 or 64 bit and it can only load DLL's which match. Any attempt to load a DLL which does not match will fail and produce an error.
If you need to match 32 and 64 bit code you need to use multiple processes. In this case though I would just make the application 32 bit or the DLL 64 bit | Do you want to build a 64-bit application, or you want to build an application that will run in a 64-bit environment? Your application can run perfectly fine in a 64-bit environment even when the target platform is x86. |
7,916 | Are there situations in which a pilot could/has to lower the landing gear during flight for reasons not directly connected to landing? (i.e., not part of the landing checklist)
Originally I thought I had seen some around the location indicated by the pin on the map below (17° 25' 30.093" N, 78° 32' 27.4734" E), in the evening time around 4:00 and the weather was clear.
[](https://i.stack.imgur.com/78nOO.jpg) | 2014/07/28 | [
"https://aviation.stackexchange.com/questions/7916",
"https://aviation.stackexchange.com",
"https://aviation.stackexchange.com/users/3012/"
] | Yes. If you want to increase drag to lose altitude quickly. For example, mountain flying, need to descend rapidly and speed brakes + flaps just aren't cutting it.
Fun fact: The F4U Corsair used its landing gear as speed brakes. There was a special way they lowered them in this case. (I belive the hydraulic struts weren't locked ect., so landing on them would not be smart) | I cannot imagine much need to lower the gear during flight, except perhaps if there was an issue. Also doing so mid flight would required restricting speed to the lower of Vlo (landing gear operating speed) or Vle (landing gear extended speed).
The actions that one takes that involve dropping the gear are usually part of some error handling procedure. These may be documented in operational manual or be something defined during training on the specific aircraft.
The one time I dropped gear in flight it was after one of the gear lights failed to turn off (indicating gear up and stowed) after retract. I slowed up to stay within the operational limits, dropped the gear and then retracted the gear. This time the gear light stayed off. After landing I checked the gear switches for a stuck piston or loose wire. I did not find anything and the problem never repeated.
If the problem had been something like a gear motor circuit breaker popping I would have reset the breaker ONCE. If the breaker popped again I would have cranked the gear down and left it down. |
7,916 | Are there situations in which a pilot could/has to lower the landing gear during flight for reasons not directly connected to landing? (i.e., not part of the landing checklist)
Originally I thought I had seen some around the location indicated by the pin on the map below (17° 25' 30.093" N, 78° 32' 27.4734" E), in the evening time around 4:00 and the weather was clear.
[](https://i.stack.imgur.com/78nOO.jpg) | 2014/07/28 | [
"https://aviation.stackexchange.com/questions/7916",
"https://aviation.stackexchange.com",
"https://aviation.stackexchange.com/users/3012/"
] | I am on a U.S. Air flight right now. Pretty sure that the plane is an A330. About 20 minutes after take-off, the pilot said that he had to lower the landing gear to cool off the brakes. After about 3 minutes of much noise, and some chop, he raised them and said that it had worked. | Sure it's a private ***jet***? Plenty of single-engine piston powered aircraft have fixed landing gear.
Most jets cruise at high altitudes, so if you can a) see the aircraft, b) identify it as non-commercial, c) notice the landing gear is down, and d) claim that it's not near an airfield then it's more likely that it is a 4-6 seat piston single with fixed gear. Cessna, Piper, Beechcraft have made thousands.
Addendum to edited question:
You say there are no airports *near by*. Possible there's one a little further away? Planes typically raise the gear as soon as they are off the runway, but they lower it 30km out. And that's 30km flying distance, not driving diatance. |
7,916 | Are there situations in which a pilot could/has to lower the landing gear during flight for reasons not directly connected to landing? (i.e., not part of the landing checklist)
Originally I thought I had seen some around the location indicated by the pin on the map below (17° 25' 30.093" N, 78° 32' 27.4734" E), in the evening time around 4:00 and the weather was clear.
[](https://i.stack.imgur.com/78nOO.jpg) | 2014/07/28 | [
"https://aviation.stackexchange.com/questions/7916",
"https://aviation.stackexchange.com",
"https://aviation.stackexchange.com/users/3012/"
] | That's **nowhere near midflight**. You are seeing aircrafts approaching [Begumpet Airport (VOHY)](http://ourairports.com/airports/VOHY/)'s runway 27. This airport has no airline service, but it is used for some general aviation including VIP flights and as military airbase.
The point directly north (about 3 km) from the coordinates you gave ([N17° 25' 30", E78° 32' 27"](https://www.google.com/maps/place/17%C2%B025'30.0%22N+78%C2%B032'27.0%22E/@17.4532706,78.5342887,13z/data=!4m2!3m1!1s0x0:0x0)) is about 6 km, or 3.2 nm, from threshold of VOHY runway 27. Given usual 3° glide slope the aircraft would be just about 1000 ft above runway elevation, which happens to be the latest point where landing checklist should be complete. Yes, that means gear down. It also means it will be touching down in about a minute and a half. | Sure it's a private ***jet***? Plenty of single-engine piston powered aircraft have fixed landing gear.
Most jets cruise at high altitudes, so if you can a) see the aircraft, b) identify it as non-commercial, c) notice the landing gear is down, and d) claim that it's not near an airfield then it's more likely that it is a 4-6 seat piston single with fixed gear. Cessna, Piper, Beechcraft have made thousands.
Addendum to edited question:
You say there are no airports *near by*. Possible there's one a little further away? Planes typically raise the gear as soon as they are off the runway, but they lower it 30km out. And that's 30km flying distance, not driving diatance. |
7,916 | Are there situations in which a pilot could/has to lower the landing gear during flight for reasons not directly connected to landing? (i.e., not part of the landing checklist)
Originally I thought I had seen some around the location indicated by the pin on the map below (17° 25' 30.093" N, 78° 32' 27.4734" E), in the evening time around 4:00 and the weather was clear.
[](https://i.stack.imgur.com/78nOO.jpg) | 2014/07/28 | [
"https://aviation.stackexchange.com/questions/7916",
"https://aviation.stackexchange.com",
"https://aviation.stackexchange.com/users/3012/"
] | The reasons I can think of offhand for extending the gear for other than landing are:
* As has been mentioned in a previous answer, use of the landing gear as a speed brake. The Fokker F-27 had a speed brake switch on the front panel that when used lowered the main landing gear but left the nose gear retracted. At the two 747 carriers I worked for in the 1990s, we occasionally dropped the gear to get more drag for a steeper descent. As I remember the max gear extension/retraction speed was 270 knots, but once extended the max speed was 320 knots.
* To cool hot brakes or hot tires. This was the most common reason in my experience for extending the gear. The 747-100/200 was supposed to be taxied at no greater than 25 kts, which meant that braking was needed during taxi even with engines at idle. Tire flexing also produced significant heat. There was a recommendation not to taxi more than 30,000 feet as I remember because of these factors. If you were using, say, the reef runway at Honolulu, you exceeded that distance by the time you lifted off, and if you were above 800,000 lbs you were guaranteed serious heating.
* To pre-cool the brakes and tires if you had a short leg followed by a quick turn. The 747 was originally designed to stay in the air for awhile before landing. The story I most often heard was they designed for 5.5 hours of cooling in the wheel wells before the gear would be used.
* To burn extra fuel to get below landing weight. Rare, but it could happen if you were tankering fuel such to arrive at max landing weight and for whatever reason the leg burn was less than planned. Fuel burn increase with the landing gear down is quite dramatic. We were tankering fuel once from Yakota, Japan to Osan, Korea, and we couldn't get the landing gear up. Our choices were to dump fuel and return to Yakota or to proceed to Osan with the gear down. We chose the latter. We couldn't get above 25,000 and our fuel burn was twice normal. Confused the controllers; they kept wondering by we were so slow and so low. We kept having to explain. | I am on a U.S. Air flight right now. Pretty sure that the plane is an A330. About 20 minutes after take-off, the pilot said that he had to lower the landing gear to cool off the brakes. After about 3 minutes of much noise, and some chop, he raised them and said that it had worked. |
7,916 | Are there situations in which a pilot could/has to lower the landing gear during flight for reasons not directly connected to landing? (i.e., not part of the landing checklist)
Originally I thought I had seen some around the location indicated by the pin on the map below (17° 25' 30.093" N, 78° 32' 27.4734" E), in the evening time around 4:00 and the weather was clear.
[](https://i.stack.imgur.com/78nOO.jpg) | 2014/07/28 | [
"https://aviation.stackexchange.com/questions/7916",
"https://aviation.stackexchange.com",
"https://aviation.stackexchange.com/users/3012/"
] | Landing gears are generally retracted to decrease drag in flight . As the speed of
an aircraft increases, so does parasite drag. Mechanisms to retract and stow the landing gear to eliminate parasite drag add weight to the aircraft.
Private Jets generally use Tricycle-type landing gear with dual main wheels . One of the main advantages of using the Tricycle-type landing gear is that it prevents ground-looping of the aircraft. Since the aircraft center of gravity is forward of the main gear, forces acting on the center of gravity tend to keep the aircraft moving forward rather than looping, such as with a tail wheel-type landing gear.
It is not necessary to retract the landing gear . Infact there are Landing gears that are Fixed as can be seen in many small, single engine , light aircrafts .
On certain occasions Private jets as well as large aircrafts like the Boeing 777 extend their landing gear during flight **to cool the Brakes** because :
1. *The brakes may have been heated by the previous landing and not had time to cool while the airplane was at the gate*.
2. *During taxi out, they were further heated by necessary brake applications*.
3. *After takeoff, the landing gear retracted into the wheel well where there is limited cooling air*. | Sure it's a private ***jet***? Plenty of single-engine piston powered aircraft have fixed landing gear.
Most jets cruise at high altitudes, so if you can a) see the aircraft, b) identify it as non-commercial, c) notice the landing gear is down, and d) claim that it's not near an airfield then it's more likely that it is a 4-6 seat piston single with fixed gear. Cessna, Piper, Beechcraft have made thousands.
Addendum to edited question:
You say there are no airports *near by*. Possible there's one a little further away? Planes typically raise the gear as soon as they are off the runway, but they lower it 30km out. And that's 30km flying distance, not driving diatance. |
7,916 | Are there situations in which a pilot could/has to lower the landing gear during flight for reasons not directly connected to landing? (i.e., not part of the landing checklist)
Originally I thought I had seen some around the location indicated by the pin on the map below (17° 25' 30.093" N, 78° 32' 27.4734" E), in the evening time around 4:00 and the weather was clear.
[](https://i.stack.imgur.com/78nOO.jpg) | 2014/07/28 | [
"https://aviation.stackexchange.com/questions/7916",
"https://aviation.stackexchange.com",
"https://aviation.stackexchange.com/users/3012/"
] | That's **nowhere near midflight**. You are seeing aircrafts approaching [Begumpet Airport (VOHY)](http://ourairports.com/airports/VOHY/)'s runway 27. This airport has no airline service, but it is used for some general aviation including VIP flights and as military airbase.
The point directly north (about 3 km) from the coordinates you gave ([N17° 25' 30", E78° 32' 27"](https://www.google.com/maps/place/17%C2%B025'30.0%22N+78%C2%B032'27.0%22E/@17.4532706,78.5342887,13z/data=!4m2!3m1!1s0x0:0x0)) is about 6 km, or 3.2 nm, from threshold of VOHY runway 27. Given usual 3° glide slope the aircraft would be just about 1000 ft above runway elevation, which happens to be the latest point where landing checklist should be complete. Yes, that means gear down. It also means it will be touching down in about a minute and a half. | The reasons I can think of offhand for extending the gear for other than landing are:
* As has been mentioned in a previous answer, use of the landing gear as a speed brake. The Fokker F-27 had a speed brake switch on the front panel that when used lowered the main landing gear but left the nose gear retracted. At the two 747 carriers I worked for in the 1990s, we occasionally dropped the gear to get more drag for a steeper descent. As I remember the max gear extension/retraction speed was 270 knots, but once extended the max speed was 320 knots.
* To cool hot brakes or hot tires. This was the most common reason in my experience for extending the gear. The 747-100/200 was supposed to be taxied at no greater than 25 kts, which meant that braking was needed during taxi even with engines at idle. Tire flexing also produced significant heat. There was a recommendation not to taxi more than 30,000 feet as I remember because of these factors. If you were using, say, the reef runway at Honolulu, you exceeded that distance by the time you lifted off, and if you were above 800,000 lbs you were guaranteed serious heating.
* To pre-cool the brakes and tires if you had a short leg followed by a quick turn. The 747 was originally designed to stay in the air for awhile before landing. The story I most often heard was they designed for 5.5 hours of cooling in the wheel wells before the gear would be used.
* To burn extra fuel to get below landing weight. Rare, but it could happen if you were tankering fuel such to arrive at max landing weight and for whatever reason the leg burn was less than planned. Fuel burn increase with the landing gear down is quite dramatic. We were tankering fuel once from Yakota, Japan to Osan, Korea, and we couldn't get the landing gear up. Our choices were to dump fuel and return to Yakota or to proceed to Osan with the gear down. We chose the latter. We couldn't get above 25,000 and our fuel burn was twice normal. Confused the controllers; they kept wondering by we were so slow and so low. We kept having to explain. |
7,916 | Are there situations in which a pilot could/has to lower the landing gear during flight for reasons not directly connected to landing? (i.e., not part of the landing checklist)
Originally I thought I had seen some around the location indicated by the pin on the map below (17° 25' 30.093" N, 78° 32' 27.4734" E), in the evening time around 4:00 and the weather was clear.
[](https://i.stack.imgur.com/78nOO.jpg) | 2014/07/28 | [
"https://aviation.stackexchange.com/questions/7916",
"https://aviation.stackexchange.com",
"https://aviation.stackexchange.com/users/3012/"
] | I cannot imagine much need to lower the gear during flight, except perhaps if there was an issue. Also doing so mid flight would required restricting speed to the lower of Vlo (landing gear operating speed) or Vle (landing gear extended speed).
The actions that one takes that involve dropping the gear are usually part of some error handling procedure. These may be documented in operational manual or be something defined during training on the specific aircraft.
The one time I dropped gear in flight it was after one of the gear lights failed to turn off (indicating gear up and stowed) after retract. I slowed up to stay within the operational limits, dropped the gear and then retracted the gear. This time the gear light stayed off. After landing I checked the gear switches for a stuck piston or loose wire. I did not find anything and the problem never repeated.
If the problem had been something like a gear motor circuit breaker popping I would have reset the breaker ONCE. If the breaker popped again I would have cranked the gear down and left it down. | Sure it's a private ***jet***? Plenty of single-engine piston powered aircraft have fixed landing gear.
Most jets cruise at high altitudes, so if you can a) see the aircraft, b) identify it as non-commercial, c) notice the landing gear is down, and d) claim that it's not near an airfield then it's more likely that it is a 4-6 seat piston single with fixed gear. Cessna, Piper, Beechcraft have made thousands.
Addendum to edited question:
You say there are no airports *near by*. Possible there's one a little further away? Planes typically raise the gear as soon as they are off the runway, but they lower it 30km out. And that's 30km flying distance, not driving diatance. |
7,916 | Are there situations in which a pilot could/has to lower the landing gear during flight for reasons not directly connected to landing? (i.e., not part of the landing checklist)
Originally I thought I had seen some around the location indicated by the pin on the map below (17° 25' 30.093" N, 78° 32' 27.4734" E), in the evening time around 4:00 and the weather was clear.
[](https://i.stack.imgur.com/78nOO.jpg) | 2014/07/28 | [
"https://aviation.stackexchange.com/questions/7916",
"https://aviation.stackexchange.com",
"https://aviation.stackexchange.com/users/3012/"
] | That's **nowhere near midflight**. You are seeing aircrafts approaching [Begumpet Airport (VOHY)](http://ourairports.com/airports/VOHY/)'s runway 27. This airport has no airline service, but it is used for some general aviation including VIP flights and as military airbase.
The point directly north (about 3 km) from the coordinates you gave ([N17° 25' 30", E78° 32' 27"](https://www.google.com/maps/place/17%C2%B025'30.0%22N+78%C2%B032'27.0%22E/@17.4532706,78.5342887,13z/data=!4m2!3m1!1s0x0:0x0)) is about 6 km, or 3.2 nm, from threshold of VOHY runway 27. Given usual 3° glide slope the aircraft would be just about 1000 ft above runway elevation, which happens to be the latest point where landing checklist should be complete. Yes, that means gear down. It also means it will be touching down in about a minute and a half. | Yes. If you want to increase drag to lose altitude quickly. For example, mountain flying, need to descend rapidly and speed brakes + flaps just aren't cutting it.
Fun fact: The F4U Corsair used its landing gear as speed brakes. There was a special way they lowered them in this case. (I belive the hydraulic struts weren't locked ect., so landing on them would not be smart) |
7,916 | Are there situations in which a pilot could/has to lower the landing gear during flight for reasons not directly connected to landing? (i.e., not part of the landing checklist)
Originally I thought I had seen some around the location indicated by the pin on the map below (17° 25' 30.093" N, 78° 32' 27.4734" E), in the evening time around 4:00 and the weather was clear.
[](https://i.stack.imgur.com/78nOO.jpg) | 2014/07/28 | [
"https://aviation.stackexchange.com/questions/7916",
"https://aviation.stackexchange.com",
"https://aviation.stackexchange.com/users/3012/"
] | Landing gears are generally retracted to decrease drag in flight . As the speed of
an aircraft increases, so does parasite drag. Mechanisms to retract and stow the landing gear to eliminate parasite drag add weight to the aircraft.
Private Jets generally use Tricycle-type landing gear with dual main wheels . One of the main advantages of using the Tricycle-type landing gear is that it prevents ground-looping of the aircraft. Since the aircraft center of gravity is forward of the main gear, forces acting on the center of gravity tend to keep the aircraft moving forward rather than looping, such as with a tail wheel-type landing gear.
It is not necessary to retract the landing gear . Infact there are Landing gears that are Fixed as can be seen in many small, single engine , light aircrafts .
On certain occasions Private jets as well as large aircrafts like the Boeing 777 extend their landing gear during flight **to cool the Brakes** because :
1. *The brakes may have been heated by the previous landing and not had time to cool while the airplane was at the gate*.
2. *During taxi out, they were further heated by necessary brake applications*.
3. *After takeoff, the landing gear retracted into the wheel well where there is limited cooling air*. | I cannot imagine much need to lower the gear during flight, except perhaps if there was an issue. Also doing so mid flight would required restricting speed to the lower of Vlo (landing gear operating speed) or Vle (landing gear extended speed).
The actions that one takes that involve dropping the gear are usually part of some error handling procedure. These may be documented in operational manual or be something defined during training on the specific aircraft.
The one time I dropped gear in flight it was after one of the gear lights failed to turn off (indicating gear up and stowed) after retract. I slowed up to stay within the operational limits, dropped the gear and then retracted the gear. This time the gear light stayed off. After landing I checked the gear switches for a stuck piston or loose wire. I did not find anything and the problem never repeated.
If the problem had been something like a gear motor circuit breaker popping I would have reset the breaker ONCE. If the breaker popped again I would have cranked the gear down and left it down. |
7,916 | Are there situations in which a pilot could/has to lower the landing gear during flight for reasons not directly connected to landing? (i.e., not part of the landing checklist)
Originally I thought I had seen some around the location indicated by the pin on the map below (17° 25' 30.093" N, 78° 32' 27.4734" E), in the evening time around 4:00 and the weather was clear.
[](https://i.stack.imgur.com/78nOO.jpg) | 2014/07/28 | [
"https://aviation.stackexchange.com/questions/7916",
"https://aviation.stackexchange.com",
"https://aviation.stackexchange.com/users/3012/"
] | That's **nowhere near midflight**. You are seeing aircrafts approaching [Begumpet Airport (VOHY)](http://ourairports.com/airports/VOHY/)'s runway 27. This airport has no airline service, but it is used for some general aviation including VIP flights and as military airbase.
The point directly north (about 3 km) from the coordinates you gave ([N17° 25' 30", E78° 32' 27"](https://www.google.com/maps/place/17%C2%B025'30.0%22N+78%C2%B032'27.0%22E/@17.4532706,78.5342887,13z/data=!4m2!3m1!1s0x0:0x0)) is about 6 km, or 3.2 nm, from threshold of VOHY runway 27. Given usual 3° glide slope the aircraft would be just about 1000 ft above runway elevation, which happens to be the latest point where landing checklist should be complete. Yes, that means gear down. It also means it will be touching down in about a minute and a half. | I cannot imagine much need to lower the gear during flight, except perhaps if there was an issue. Also doing so mid flight would required restricting speed to the lower of Vlo (landing gear operating speed) or Vle (landing gear extended speed).
The actions that one takes that involve dropping the gear are usually part of some error handling procedure. These may be documented in operational manual or be something defined during training on the specific aircraft.
The one time I dropped gear in flight it was after one of the gear lights failed to turn off (indicating gear up and stowed) after retract. I slowed up to stay within the operational limits, dropped the gear and then retracted the gear. This time the gear light stayed off. After landing I checked the gear switches for a stuck piston or loose wire. I did not find anything and the problem never repeated.
If the problem had been something like a gear motor circuit breaker popping I would have reset the breaker ONCE. If the breaker popped again I would have cranked the gear down and left it down. |
6,092 | Currently I am finishing my masters (one year) in economics at a Canadian university and am intending to apply to Canadian universities to do a PhD.
The issue I have is that in the courses I had taken last semester the professors were closed to student contact making it near impossible to build relationships.
For my applications I intended to rely upon professors from my undergraduate university that know me quite well and who I know will write high-quality letters.
A colleague of mine mentioned that when applying for a PhD program, it is expected that my references will come from my masters university and it is generally not acceptable practice to have references from the undergraduate one.
Is this actually the case? If so, what is the best course of action? | 2013/01/09 | [
"https://academia.stackexchange.com/questions/6092",
"https://academia.stackexchange.com",
"https://academia.stackexchange.com/users/-1/"
] | A Ph.D. program is about research. Have you done research? If not, how do you know you want to study for a Ph.D.?
It is *your* responsibility to seek out opportunities for research.
Protestations that your professors were not open to communication are not likely to be viewed positively by an admissions committee.
If you've had some research experiences, have you considered asking those you worked with for a recommendation letter? If you haven't had any research experience, that will make it significantly harder to be admitted into a Ph.D. program, no matter who writes your letters.
And if you haven't been inspired to seek out opportunities to get involved in research, that would make me wonder whether you will truly enjoy a Ph.D. program. Going to a Ph.D. program "by default" or because "that's what everyone is doing" is a terrible idea; you should only join a Ph.D. program if you are passionate and excited about doing research, because that's what you are going to be spending most of your time doing in a Ph.D. program, and that is what Ph.D. programs are designed to prepare you for. So, you might also want to do a little bit of soul-searching to figure out whether a Ph.D. program truly is the right direction for you. If it's not, it's much better to find out now rather than after spending several years in a Ph.D. program.
It is acceptable to have letters of reference from a mixture of your undergraduate and your masters university. People would probably ask questions if all of your letters were from your undergraduate university and none were from your masters university. That might make the admissions committee wonder: What were you doing with your time at the M.S. program? Why didn't you seek out opportunities to get involved in research and other activities beyond coursework? Is there some hidden story? (For instance, did you completely alienate all the professors in your M.S. program? Or, do you have little self-drive to do research? Or, maybe you have little experience with research, and thus no idea whether you are good at and enjoy research, and thus little basis to judge whether a Ph.D. program is a good fit for you.)
That said, the most important thing is to have letters from people who know you well, and who know well how to evaluate candidates for Ph.D. programs. So, which professors (or other established researchers) know you well and can best comment on your research ability or research potential? | Not really. It is assumed that if you are a good student you would be able to get good reference letters from your masters courses. It would have to be from your undergraduate thesis advisor or some sort of exceptional activity you did during undergrad, not just a regular class with a good grade, if at all. |
2,433,496 | I have created a blogging system with php+postgresql.
Now I want to add a web chat ( in REAL TIME for Million of users simultaneously ) where every message is saved in database.
I am thinking to use Erlang+Mnesia on a different webserver for this issue.
Message's table will be like this:
message\_id, user\_id, message, date
user\_id should be related with users table in Postgresql database in another webserver.
How can I do that without lose performance ?
If you have any other creative solutions tell me please ;). | 2010/03/12 | [
"https://Stackoverflow.com/questions/2433496",
"https://Stackoverflow.com",
"https://Stackoverflow.com/users/244413/"
] | I'm not sure why you want to save every single message in a database, but mnesia doesn't sound like a particularly good choice for doing that. Mnesia is more of a distributed key-value store, that you can use to keep the state of your application, when you need to store "tabular data" and query it, in a simple to medium-complex fashion.
For large amounts of text, I've heard lucene is supposed to be good, it has fulltext search features etc. which are said to be efficient, you might want to look into it:
[Apache Lucene Project page](http://lucene.apache.org/java/docs/index.html)
Other than that, using erlang as chatserver, using mnesia to hold all the other state sounds like a good idea, You could write a javascript client that uses something like JSONP (to overcome the cross-domaine-issue) and mochiweb on the erlang site to do the webserver part.
Writing the rest of the core chat system should be fairly simple, the fun part, so to say :) | Mnesia can certainly do what you suggest but if you've already got postgres set up is there some reason you don't want to use that? It might be simpler than creating a whole seperate service and if you want erlang to run the chat service then it has postgres drivers. |
2,433,496 | I have created a blogging system with php+postgresql.
Now I want to add a web chat ( in REAL TIME for Million of users simultaneously ) where every message is saved in database.
I am thinking to use Erlang+Mnesia on a different webserver for this issue.
Message's table will be like this:
message\_id, user\_id, message, date
user\_id should be related with users table in Postgresql database in another webserver.
How can I do that without lose performance ?
If you have any other creative solutions tell me please ;). | 2010/03/12 | [
"https://Stackoverflow.com/questions/2433496",
"https://Stackoverflow.com",
"https://Stackoverflow.com/users/244413/"
] | I'm not sure why you want to save every single message in a database, but mnesia doesn't sound like a particularly good choice for doing that. Mnesia is more of a distributed key-value store, that you can use to keep the state of your application, when you need to store "tabular data" and query it, in a simple to medium-complex fashion.
For large amounts of text, I've heard lucene is supposed to be good, it has fulltext search features etc. which are said to be efficient, you might want to look into it:
[Apache Lucene Project page](http://lucene.apache.org/java/docs/index.html)
Other than that, using erlang as chatserver, using mnesia to hold all the other state sounds like a good idea, You could write a javascript client that uses something like JSONP (to overcome the cross-domaine-issue) and mochiweb on the erlang site to do the webserver part.
Writing the rest of the core chat system should be fairly simple, the fun part, so to say :) | This project is using postgresql with great success.
<http://zotonic.com/>
You may want to use the same code for db access to postgresql. |
4,334,206 | I have a problem in building a c thread program. Program is giving error like
"undefined reference to pthread\_creat".
I searched and found to use gcc options like
"gcc -lpthread -o ...."
But I not able to set it for eclipse. I tried to make change in makefile but every time it got replaced with default options. Please help me to set these gcc options and write about where and how to set gcc options in eclipse on fedora 10.
Thanks,
Lokesh | 2010/12/02 | [
"https://Stackoverflow.com/questions/4334206",
"https://Stackoverflow.com",
"https://Stackoverflow.com/users/527850/"
] | to add pthread library to your project flow these steps (in eclipse):
right cklick on the project in the project explorer -> properties -> c/c++ build -> Settings -> linker -> libraries -> add -> pthread -> ok -> rebuild | Check [this](http://blog.asteriosk.gr/2009/02/15/adding-pthread-to-eclipse-for-using-posix-threads/) 'tutorial' on about how to setup eclipse for developing posix threads.
Hope it helps. |
4,334,206 | I have a problem in building a c thread program. Program is giving error like
"undefined reference to pthread\_creat".
I searched and found to use gcc options like
"gcc -lpthread -o ...."
But I not able to set it for eclipse. I tried to make change in makefile but every time it got replaced with default options. Please help me to set these gcc options and write about where and how to set gcc options in eclipse on fedora 10.
Thanks,
Lokesh | 2010/12/02 | [
"https://Stackoverflow.com/questions/4334206",
"https://Stackoverflow.com",
"https://Stackoverflow.com/users/527850/"
] | to add pthread library to your project flow these steps (in eclipse):
right cklick on the project in the project explorer -> properties -> c/c++ build -> Settings -> linker -> libraries -> add -> pthread -> ok -> rebuild | To add pthread library to your non-makefile project, do following steps (in eclipse):
right click on the project in the project explorer. Select properties -> c/c++ general -> Paths and Symbols -> libraries -> add -> type 'pthread' in text box -> ok -> ok -> rebuild |
45,233 | Right after the event, I felt shocked and depressed. I've been engaging in stocks for about a year now but I've never encountered such a big jump in such a short time. What I'm planning to do is just wait for it to rise again, which I'm not sure when. (Well, who is?)
**What should my mindset be?**
---
I understand that there are already lots of questions regarding **When should I sell?** or **Should I set a stop loss?** For me, this question is not 100% about how to protect your money, but it's more of **In extreme cases like this, how should I mentally prepare myself?**
I anticipate that there will be comments/answers like "we can't give advice if we don't know the exact stock in topic" or somewhere along those lines. I want to pre-emptively tackle this and say that this question is not only for my specific current case. I'd prefer answers to be generic for everyone facing the same problem. | 2015/03/05 | [
"https://money.stackexchange.com/questions/45233",
"https://money.stackexchange.com",
"https://money.stackexchange.com/users/19483/"
] | You bought the stock at some point in the past. You must have had a reason for this purchase. Has the recent change in price changed the reason you bought the stock?
You must assume your losses are [sunk costs](http://en.wikipedia.org/wiki/Sunk_costs). No matter what action you take, you can not recover your losses. Do not attempt to hold the stock in the hopes of regaining value, or sell it to stop losses. Instead approach this event as if this very day, you were given shares of the company's stock at their current market value for free as a gift. In this hypothetical situation, would you hold the shares, or sell them? Use that to judge your options.
Not everyone, myself included, can handle the mental stress of watching share prices change. You can always consider trading index funds instead, which are much less volatile but will provide consistent, albeit, boring returns. This may or may not be you, but it's an option.
Finally, do not keep money in the market you are not prepared to lose. It seems obvious, but if you lost 40% today, you could lose 100% tomorrow. | Have the reasons you originally purchased the stock changed? Is the company still sound? Does the company have a new competitor? Has the company changed the way they operate?
If the company is the same, except for stock price, why would you change your mind on the company now?
ESPECIALLY if the company has not changed, -- but only other people's PERCEPTION of the company, then your original reasons for buying it are still valid.
In fact, if you are not a day-trader, then this COMPANY JUST WENT ON SALE and you should buy more.
If you are a day trader, then you do care about the herd's perception of value (not true value) and you should sell.
DAY TRADER = SELL
BUY AND HOLD (WITH INTELLIGENT RESEARCH) = BUY MORE |
45,233 | Right after the event, I felt shocked and depressed. I've been engaging in stocks for about a year now but I've never encountered such a big jump in such a short time. What I'm planning to do is just wait for it to rise again, which I'm not sure when. (Well, who is?)
**What should my mindset be?**
---
I understand that there are already lots of questions regarding **When should I sell?** or **Should I set a stop loss?** For me, this question is not 100% about how to protect your money, but it's more of **In extreme cases like this, how should I mentally prepare myself?**
I anticipate that there will be comments/answers like "we can't give advice if we don't know the exact stock in topic" or somewhere along those lines. I want to pre-emptively tackle this and say that this question is not only for my specific current case. I'd prefer answers to be generic for everyone facing the same problem. | 2015/03/05 | [
"https://money.stackexchange.com/questions/45233",
"https://money.stackexchange.com",
"https://money.stackexchange.com/users/19483/"
] | You bought the stock at some point in the past. You must have had a reason for this purchase. Has the recent change in price changed the reason you bought the stock?
You must assume your losses are [sunk costs](http://en.wikipedia.org/wiki/Sunk_costs). No matter what action you take, you can not recover your losses. Do not attempt to hold the stock in the hopes of regaining value, or sell it to stop losses. Instead approach this event as if this very day, you were given shares of the company's stock at their current market value for free as a gift. In this hypothetical situation, would you hold the shares, or sell them? Use that to judge your options.
Not everyone, myself included, can handle the mental stress of watching share prices change. You can always consider trading index funds instead, which are much less volatile but will provide consistent, albeit, boring returns. This may or may not be you, but it's an option.
Finally, do not keep money in the market you are not prepared to lose. It seems obvious, but if you lost 40% today, you could lose 100% tomorrow. | Did you read [Soichiro Honda](https://en.wikipedia.org/wiki/Soichiro_Honda)'s biography? He is the founder of [Honda Motor](https://en.wikipedia.org/wiki/Honda).
His plant was destroyed by an earthquake, and then he proceeded to build another factory which, as World War II broke out, was lost again with his money, and many of his friends', but **he started again**. |
45,233 | Right after the event, I felt shocked and depressed. I've been engaging in stocks for about a year now but I've never encountered such a big jump in such a short time. What I'm planning to do is just wait for it to rise again, which I'm not sure when. (Well, who is?)
**What should my mindset be?**
---
I understand that there are already lots of questions regarding **When should I sell?** or **Should I set a stop loss?** For me, this question is not 100% about how to protect your money, but it's more of **In extreme cases like this, how should I mentally prepare myself?**
I anticipate that there will be comments/answers like "we can't give advice if we don't know the exact stock in topic" or somewhere along those lines. I want to pre-emptively tackle this and say that this question is not only for my specific current case. I'd prefer answers to be generic for everyone facing the same problem. | 2015/03/05 | [
"https://money.stackexchange.com/questions/45233",
"https://money.stackexchange.com",
"https://money.stackexchange.com/users/19483/"
] | First: do you understand why it dropped? Was it overvalued before, or is this an overreaction to some piece of news about them, or about their industry, or...? Arguably, if you can't answer that, you aren't paying enough attention to have been betting on that individual stock.
Assuming you do understand why this price swing occurred -- or if you're convinced you know better than the folks who sold at that price -- do you believe the stock will recover a significant part of its value any time soon, or at least show a nice rate of growth from where it is now? If so, you might want to hold onto it, risking further losses against the chance of recovering part or all of what is -- at this moment -- only a loss on paper. Basically: if, having just seen it drop, you'd still consider buying it at the new price you should "buy it from yourself" and go on from here. That way at least you aren't doing exactly what you hope to avoid, buying high and selling low. Heck, if you *really* believe in the stock, you could see this as a buying opportunity...
On the other hand, if you do *not* believe you would buy it now at its new price, and if you see an alternative which will grow more rapidly, you should take your losses and move your money to that other stock. Or split the difference if you aren't sure which is better but can figure out approximately how unsure you are.
The question is how you move on from here, more than how you got here. What happened happened. What do you think will happen next, and how much are you willing to bet on it?
On the gripping hand: This is part of how the market operates. Risk and potential reward tend to be pretty closely tied to each other. You can reduce risk by diversifying across multiple investments so no one company/sector/market can hurt you too badly --- and almost anyone sane will tell you that you *should* diversify -- but that means giving up some of the chance for big winnings too. You probably want to be cautious with most of your money and go for the longer odds only with a small portion that you can afford to lose on.
If this is really stressing you out, you may not want to play with individual stocks. Mutual funds have some volatility too, but they're inherently diversified to a greater or lesser extent. They will rarely delight you, but they won't usually slap you this way either. | The mental approach should be that you always knew the risk of gambling and it was extra money that you had (or should have had). Now think that the 'horse' race is not over and in the near future it will pick up pace against the others and be back on track. |
45,233 | Right after the event, I felt shocked and depressed. I've been engaging in stocks for about a year now but I've never encountered such a big jump in such a short time. What I'm planning to do is just wait for it to rise again, which I'm not sure when. (Well, who is?)
**What should my mindset be?**
---
I understand that there are already lots of questions regarding **When should I sell?** or **Should I set a stop loss?** For me, this question is not 100% about how to protect your money, but it's more of **In extreme cases like this, how should I mentally prepare myself?**
I anticipate that there will be comments/answers like "we can't give advice if we don't know the exact stock in topic" or somewhere along those lines. I want to pre-emptively tackle this and say that this question is not only for my specific current case. I'd prefer answers to be generic for everyone facing the same problem. | 2015/03/05 | [
"https://money.stackexchange.com/questions/45233",
"https://money.stackexchange.com",
"https://money.stackexchange.com/users/19483/"
] | Have the reasons you originally purchased the stock changed? Is the company still sound? Does the company have a new competitor? Has the company changed the way they operate?
If the company is the same, except for stock price, why would you change your mind on the company now?
ESPECIALLY if the company has not changed, -- but only other people's PERCEPTION of the company, then your original reasons for buying it are still valid.
In fact, if you are not a day-trader, then this COMPANY JUST WENT ON SALE and you should buy more.
If you are a day trader, then you do care about the herd's perception of value (not true value) and you should sell.
DAY TRADER = SELL
BUY AND HOLD (WITH INTELLIGENT RESEARCH) = BUY MORE | Hopefully, before you invested in this stock, you evaluated the company. You looked at the financial information about the company and where the company was headed, and evaluated whether the stock was undervalued or overvalued. Hopefully, you determined that the stock was undervalued at the time you bought it.
The thing to do now is to reevaluate the stock. Do you think the stock is overvalued or undervalued right now? If you didn't own it, would you buy it today? Instead of looking at the past performance of the stock, you want to try to determine which direction the stock will go from today. If you wouldn't buy it today at it's current price, then you should sell.
If you have no idea how to do this evaluation, neither do I. For me, with the investing knowledge I have right now, investing in an individual stock would be way too risky. If you don't know how to evaluate a stock and determine if it is a good buy or not, then you should stay away from individual stocks and instead invest in stock mutual funds, which lower the risk by diversifying over lots of stocks. |
45,233 | Right after the event, I felt shocked and depressed. I've been engaging in stocks for about a year now but I've never encountered such a big jump in such a short time. What I'm planning to do is just wait for it to rise again, which I'm not sure when. (Well, who is?)
**What should my mindset be?**
---
I understand that there are already lots of questions regarding **When should I sell?** or **Should I set a stop loss?** For me, this question is not 100% about how to protect your money, but it's more of **In extreme cases like this, how should I mentally prepare myself?**
I anticipate that there will be comments/answers like "we can't give advice if we don't know the exact stock in topic" or somewhere along those lines. I want to pre-emptively tackle this and say that this question is not only for my specific current case. I'd prefer answers to be generic for everyone facing the same problem. | 2015/03/05 | [
"https://money.stackexchange.com/questions/45233",
"https://money.stackexchange.com",
"https://money.stackexchange.com/users/19483/"
] | Like @chirs, I'm of the opinion that you *might* want to buy more.
I've done this a couple of times, price dropped a bunch, and I said, heck, I bought some last week, and this week I can get twice as much stock for about the same price.
Brought down my average cost per share, and when the company was taken private, I actually didn't lose money - unlike some other people I know, who only bought at one price, watched the drop, and held on awaiting a recovery (which didn't happen in time before the big money swooped in on it).
But to do this, you need to keep cash reserves (that, like @afforess says, you can afford to lose all of) on hand, awaiting buying opportunities. This, too, is a cost - an opportunity cost. | Did you read [Soichiro Honda](https://en.wikipedia.org/wiki/Soichiro_Honda)'s biography? He is the founder of [Honda Motor](https://en.wikipedia.org/wiki/Honda).
His plant was destroyed by an earthquake, and then he proceeded to build another factory which, as World War II broke out, was lost again with his money, and many of his friends', but **he started again**. |
45,233 | Right after the event, I felt shocked and depressed. I've been engaging in stocks for about a year now but I've never encountered such a big jump in such a short time. What I'm planning to do is just wait for it to rise again, which I'm not sure when. (Well, who is?)
**What should my mindset be?**
---
I understand that there are already lots of questions regarding **When should I sell?** or **Should I set a stop loss?** For me, this question is not 100% about how to protect your money, but it's more of **In extreme cases like this, how should I mentally prepare myself?**
I anticipate that there will be comments/answers like "we can't give advice if we don't know the exact stock in topic" or somewhere along those lines. I want to pre-emptively tackle this and say that this question is not only for my specific current case. I'd prefer answers to be generic for everyone facing the same problem. | 2015/03/05 | [
"https://money.stackexchange.com/questions/45233",
"https://money.stackexchange.com",
"https://money.stackexchange.com/users/19483/"
] | You bought the stock at some point in the past. You must have had a reason for this purchase. Has the recent change in price changed the reason you bought the stock?
You must assume your losses are [sunk costs](http://en.wikipedia.org/wiki/Sunk_costs). No matter what action you take, you can not recover your losses. Do not attempt to hold the stock in the hopes of regaining value, or sell it to stop losses. Instead approach this event as if this very day, you were given shares of the company's stock at their current market value for free as a gift. In this hypothetical situation, would you hold the shares, or sell them? Use that to judge your options.
Not everyone, myself included, can handle the mental stress of watching share prices change. You can always consider trading index funds instead, which are much less volatile but will provide consistent, albeit, boring returns. This may or may not be you, but it's an option.
Finally, do not keep money in the market you are not prepared to lose. It seems obvious, but if you lost 40% today, you could lose 100% tomorrow. | I haven't seen anyone mention tax considerations and that's why I'm answering this. The rest of my answer is probably covered in the aggregate of other responses.
Here's how I would look at this in a taxable (not an IRA) account:
This could be an opportunity to harvest the tax losses to offset taxable gains this year or in future years. Unless I have compelling reasons to believe that the price will recover by at least (Loss% x ApplicableTaxRate) in the next 31 days then I would take the known - IRS tables - opportunities over the unknown.
Here's what I would consider for all accounts:
Is this the most likely place to earn a good return on my money and is it contributing to a strategy that fits my risk tolerance? You might need to get some emotional distance from the pain to make this determination objectively.
As you consider your trading and investment strategy going forward consider that when it hurts and you have to pull yourself up by the bootstraps to think clearly about your situation, you were most likely trading with too much size for you in that particular position. I'm willing to make exceptions to that rule of thumb, but it's a good way to use the painful losses as a gut check on how your strategy fits your real situation.
P.S. All traders experience individual losses that hurt and find their way to the most suitable strategies for them through these painful experiences. |
45,233 | Right after the event, I felt shocked and depressed. I've been engaging in stocks for about a year now but I've never encountered such a big jump in such a short time. What I'm planning to do is just wait for it to rise again, which I'm not sure when. (Well, who is?)
**What should my mindset be?**
---
I understand that there are already lots of questions regarding **When should I sell?** or **Should I set a stop loss?** For me, this question is not 100% about how to protect your money, but it's more of **In extreme cases like this, how should I mentally prepare myself?**
I anticipate that there will be comments/answers like "we can't give advice if we don't know the exact stock in topic" or somewhere along those lines. I want to pre-emptively tackle this and say that this question is not only for my specific current case. I'd prefer answers to be generic for everyone facing the same problem. | 2015/03/05 | [
"https://money.stackexchange.com/questions/45233",
"https://money.stackexchange.com",
"https://money.stackexchange.com/users/19483/"
] | From some of your previous questions it seems like you trade quite often, so I am assuming you are not a "Buy and Hold" person. If that is the case, then have you got a written Trading Plan? Considering you don't know what to do after a 40% drop, I assume the answer to this is that you don't have a Trading Plan.
Before you enter any trade you should have your exit point for that trade pre-determined, and this should be included in your Trading Plan. You should also include how you pick the shares you buy, do you use fundamental analysis, technical analysis, a combination of the two, a dart board or some kind of advisory service? Then finally and most importantly you should have your position sizing and risk management incorporated into your Plan.
If you are doing all this, and had automatic stop loss orders placed when you entered your buy orders, then you would have been out of the stock well before your loss got to 40%.
If you are looking to hang on and hoping for the stock to recover, remember with a 40% drop, the stock will now need to rise by 67% just for you to break even on the trade. Even if the stock did recover, how long would it take? There is the potential for opportunity loss waiting for this stock to recover, and that might take years. If the stock has fallen by 40% in a short time it is most likely that it will continue to fall in the short term, and if it falls to 50%, then the recovery would need to be 100% just for you to break even.
Leave your emotions out of your trading as much as possible, have a written Trading Plan which incorporates your risk management. A good book to read on the psychology of the markets, position sizing and risk management is "Trade your way to Financial Freedom" by Van Tharp (I actually went to see him talk tonight in Sydney, all the way over from the USA). | The mental approach should be that you always knew the risk of gambling and it was extra money that you had (or should have had). Now think that the 'horse' race is not over and in the near future it will pick up pace against the others and be back on track. |
45,233 | Right after the event, I felt shocked and depressed. I've been engaging in stocks for about a year now but I've never encountered such a big jump in such a short time. What I'm planning to do is just wait for it to rise again, which I'm not sure when. (Well, who is?)
**What should my mindset be?**
---
I understand that there are already lots of questions regarding **When should I sell?** or **Should I set a stop loss?** For me, this question is not 100% about how to protect your money, but it's more of **In extreme cases like this, how should I mentally prepare myself?**
I anticipate that there will be comments/answers like "we can't give advice if we don't know the exact stock in topic" or somewhere along those lines. I want to pre-emptively tackle this and say that this question is not only for my specific current case. I'd prefer answers to be generic for everyone facing the same problem. | 2015/03/05 | [
"https://money.stackexchange.com/questions/45233",
"https://money.stackexchange.com",
"https://money.stackexchange.com/users/19483/"
] | You shouldn't be picking stocks in the first place.
From [New York Magazine, tweeted by Ezra Klein](http://nymag.com/daily/intelligencer/2015/02/hedge-funds-discover-they-can-invest-in-apple.html):
>
> New evidence for that reality comes from Goldman Sachs, via Bloomberg News. The investment bank analyzed the holdings of 854 funds with $2.1 trillion in equity positions. It found, first of all, that all those “sophisticated investors” would have been better off stashing their money in basic, hands-off index funds or mutual funds last year — both of them had higher average returns than hedge funds did. The average hedge fund returned 3 percent last year, versus 14 percent for the Standard & Poor’s 500.
>
>
>
[Mutual funds do worse than index funds](http://gregsanders.typepad.com/blog/2009/04/mutual-funds-losing-to-the-market-index-funds.html).
>
> Tangentially-related to the question of whether Wall Street types deserve their compensation packages is the yearly phenomenon in which actively managed mutual funds underperform the market. Between 2004 and 2008, 66.21% of domestic funds did worse than the S&P Composite 1500. In 2008, 64.23% underperformed. In other words, if you had a fund manager and his employees bringing their skill and knowledge to bear on your portfolio, you probably lost money as compared to the market as a whole. That's not to say you lost money in all cases. Just in most.
>
>
>
The math is really simple on this one. Stock picking is fun, but undiversified and brings you competing with Wall Streeters with math Ph.Ds. and twenty-thousand-dollars-a-year Bloomberg terminals. What do you know about Apple's new iPhone that they don't?
You should compare your emotional reaction to losing 40% in two days to your reaction to gaining 40% in two days... then compare *both* of those to losing 6% and gaining 6%, respectively.
**Picking stocks is not financially wise. Period.** | Try to value the stock as is. If you assume it will bounce back, you're currently not thinking clearly. The new price is what it is, and it will go up or down from here.
If you're quite sure that the price will go up, buy, if you're quite sure that the price will go down, sell, as usual.
If you find that you are unable to objectively value the stock, sell it off. By closing the position you will not necessarily get the best possible price. But by removing a stressful distraction you will significantly reduce the risk of making some expensive mistakes in the near future. |
7,770 | What kind of cloth should be preferred?
What should be the thickness of the cloth?
What should be the shape and size of the cloth?
Do we have to use a polythene cover on the outer side of the diaper to prevent leakage? | 2013/04/04 | [
"https://parenting.stackexchange.com/questions/7770",
"https://parenting.stackexchange.com",
"https://parenting.stackexchange.com/users/2221/"
] | From an article by Laura Schmitt for *Mothering* magazine ("Crazy for cloth: The Benefits of Cotton Diapers." By: Schmitt, Laura, *Mothering*, 07333013, Jan/Feb2003, Issue 116):
* "If you opt for a diaper and separate cover, the diaper will not be waterproof, and its main absorbent fabric will be cotton or hemp. It is best to avoid diapers that blend in polyester or other synthetic fabrics, as they repel water and therefore don't absorb as well as a 100 percent natural-fiber diaper."
* Unbleached fabric lasts longer.
* Organic cotton hasn't "been treated with pesticides and chemicals in the growth process." Organic Egyptian cotton is known for its softness.
* Terry cloth and soft flannel are durable.
* "A blend of cotton and hemp is unmatched in absorbency and comfort."
* "Polyester fleece is often used as a top layer in a diaper for the purpose of wicking moisture away from the child's body and preventing diaper rash."
* "Twill is the standard for flat, prefold diapers. It's durable and soft, and fluffs up considerably after several washings, although it can be bulky between the legs."
* For a diaper cover, choose either wool (breathes the best and can be re-waterproofed with lanolin) or cotton with an inner waterproof layer. Other waterproof fabrics do not breathe as well, but are easier to launder.
* Prefold diapers (traditional, rectangle shape) no longer need pins when used in conjunction with velcro diaper covers.
* The author prefers fitted diapers, which velcro, tie or snap creating a snug fit and preventing leakage. These still require a diaper cover.
* All-in-ones are nice to have for outings, but they are expensive, take longer to dry, and may not fit as well.
* Consider using liners or doublers for extra aborbency at night.
I accessed this article through the Ebsco databases at my library. If you would like to read the whole article, contact your local library for easy instructions. The full article also includes a cost analysis and washing instructions. | I've cloth diapered two of my three kids. No one way, one type of diaper/cover arrangement is best. It changes with the age of he child, your child's "build" (long and lean vs chubby) and the situation (night vs day, car rides vs playing outside). Sorry, but it's not as simple as 'sposies (disposable diapers). But, it is worth the effort, both physical and mental.
My go-to resource (both for advice, and for products) is www.greenmountaindiapers.com
I guess if I had to sum up my experiences, I'd offer you this:
Stay away from synthetics of any kind for your diapers themselves. Synthetic=Stinkies (and rashes!) Cotton is the best. I wish I had never spent even 10 cents on anything other than cotton.
Wool is freakin' awesome. Super super super. I love wool. And I'm not a granola girl or anything like that. It's just easy, and effective.
Here's a secret no one will tell you: old receiving blankets (the flannel ones you got a million if at your baby shower) are super cloth diapers. They are called "flats" in the cloth diaper lingo. There are tons of videos on line that show how to fold em. I love using these when I need a "trim" fit, which is tough to get with cloth.
As for "thickness" it boils down to this: Slim fit=change every two hours. Thick & bulky = 4 hours or more. Add wool as a liner and a cover and you can go all night, no wet sheets.
Polythene (PUL) covers are the norm. You can use wool too, but either way, yes, you need a cover. Exposed PUL is good for little babies who have liquid bm's every couple of hours, because you can wipe out the liner the same way you wipe baby's bum. Otherwise you need at least 10 "lined" covers per day because you have to launder the poopie out. Did I say this already? Wool is awesome. You just wipe poop off wool too. Wool covers repel stink. You only wash them once a week AT THE MOST unless you had a "blow out". (I wash mine twice a month now that my baby is almost toilet trained! )
I'd wish you luck, but more than luck you need patience and perseverance. Happy diapering. |
7,770 | What kind of cloth should be preferred?
What should be the thickness of the cloth?
What should be the shape and size of the cloth?
Do we have to use a polythene cover on the outer side of the diaper to prevent leakage? | 2013/04/04 | [
"https://parenting.stackexchange.com/questions/7770",
"https://parenting.stackexchange.com",
"https://parenting.stackexchange.com/users/2221/"
] | From an article by Laura Schmitt for *Mothering* magazine ("Crazy for cloth: The Benefits of Cotton Diapers." By: Schmitt, Laura, *Mothering*, 07333013, Jan/Feb2003, Issue 116):
* "If you opt for a diaper and separate cover, the diaper will not be waterproof, and its main absorbent fabric will be cotton or hemp. It is best to avoid diapers that blend in polyester or other synthetic fabrics, as they repel water and therefore don't absorb as well as a 100 percent natural-fiber diaper."
* Unbleached fabric lasts longer.
* Organic cotton hasn't "been treated with pesticides and chemicals in the growth process." Organic Egyptian cotton is known for its softness.
* Terry cloth and soft flannel are durable.
* "A blend of cotton and hemp is unmatched in absorbency and comfort."
* "Polyester fleece is often used as a top layer in a diaper for the purpose of wicking moisture away from the child's body and preventing diaper rash."
* "Twill is the standard for flat, prefold diapers. It's durable and soft, and fluffs up considerably after several washings, although it can be bulky between the legs."
* For a diaper cover, choose either wool (breathes the best and can be re-waterproofed with lanolin) or cotton with an inner waterproof layer. Other waterproof fabrics do not breathe as well, but are easier to launder.
* Prefold diapers (traditional, rectangle shape) no longer need pins when used in conjunction with velcro diaper covers.
* The author prefers fitted diapers, which velcro, tie or snap creating a snug fit and preventing leakage. These still require a diaper cover.
* All-in-ones are nice to have for outings, but they are expensive, take longer to dry, and may not fit as well.
* Consider using liners or doublers for extra aborbency at night.
I accessed this article through the Ebsco databases at my library. If you would like to read the whole article, contact your local library for easy instructions. The full article also includes a cost analysis and washing instructions. | When I bought ours, I bought them lightly used (don't judge. =]). That means I tried a few brands. The ones I likeds best are the one size fits all. Our boy just turned one and we have been using bumGenius since we ran out of disposables that were given to us. And the doctor just told us he's about the size of an average two year old. If I could have, I would have bought several one size fits all of some sort (15+ for one baby) but also some wool ones to sleep in that are size specific. The pee tends to leak more often out of all in ones at night than it does for disposables. The wool ones we had when he was a newborn seemed to work well, but he quickly grew out of them. It would seem very expensive to buy anything but one size fits all given the number needed for even one day and how quickly our little guy grew. That being said, he seemed way too small for the all in ones as a newborn. |
177,539 | I know this question has probably been asked before, but I'd like some advice from everyone: I'm about to have a PIP (Professional Improvement Plan) drawn up, so is my employment over?
My boss brought up two issues:
1. I wasn't showing "confidence" in client meetings when showing the software updates. Okay, this could be fair.
But what's not fair is that the last client meeting we had was 3 weeks ago! If there was an issue, why didn't my boss bring it up after the meeting? Why did he wait 3 weeks to say something?
When I asked him about this he said I should be more excited and almost act like a salesman towards the client. Okay, this is fair feedback also.
2. On my resume, I said one of my skills is "Fortran", but my resume clearly shows I haven't used it for an employer in about 5 years. My boss complained that he gave me a Fortran issue ticket that I didn't complete in time. Yet I'm rusty on it AND this is the first time that I'm hearing that he's not happy that I'm not working as quickly as he thinks I should.
When I asked him about this, he said he expects people to be masters of everything listed on their resume, even on programming languages they haven't used in years.
The PIP is coming out of the blue with no prior verbal warnings. And I've looked through my hiring agreement and every HR documentation I can find, but nothing mentions the PIP process.
The goals in my PIP includes things like "improve your confidence when presenting at the client meeting" and "improve your Fortran skills". Obviously neither of these has a measurable goal or a specific deadline. Maybe "improve your Fortran skills to finish this ticket in 80% of the allotted time" is a measurable goal, but then why not state this on the PIP?
Some other factors:
* The company seems to be hiring college graduates every few weeks. I take this to mean they have no problem with the time and costs of interviewing and hiring people.
* A possible red flag I only discovered after I started here: the longest person working here has only been here for about 3 years. This means people don't stay long, either because they're fired or they quit.
* I'm approaching 3 months at the company, which is usually a probationary period.
So my question is: is this something I can improve on and recover from? Or is it just a matter of time before I'm fired, but now they can say I didn't meet the conditions of the PIP?
---
As a follow-up:
I had a meeting with my bosses about the PIP process and I wound up putting in my resignation the next day.
In the meeting, I told them that I've already started some classes to improve my skills, but a family emergency came up, and I wouldn't be able to study over the weekend. One boss said he was disappointed that I wasn't making better progress.
The other one pulled up my resume and started going over it, job by job, saying I used Fortran 3 years ago at a previous job and that I used it 6 years ago on a second job. He asked if I was "bigging up my resume" and did I actually know Fortran, or am I just rusty?
As my spouse said, if the boss is pulling out my resume in the middle of the meeting to basically accuse me of lying about my skills, then the business relationship is over. When I said there was a miscommunication about the required skills, the second boss tried to argue that he asked about this in the interview and I said I knew it, so (again) he expected me to be an expert at it. I took this to mean this means it's not their fault for properly vetting the candidate (me) and making sure I could do what's expected, it's my fault for inflating the skills on my resume.
So, thanks to everyone for the advice. | 2021/08/12 | [
"https://workplace.stackexchange.com/questions/177539",
"https://workplace.stackexchange.com",
"https://workplace.stackexchange.com/users/128927/"
] | **Opinions differ on whether PIPs are just "you're fired!, but I don't have the paperwork yet" or not**
Whether PIPs are survivable differs significantly by company and no consensus opinion on whether you you should try and survive a PIP exists.
Nobody here can know whether this particular PIP is survivable besides your own manager. Nor is it a general corporate standard that PIPs can be survived.
This ambiguity forces you to look at it from a risk perspective. What are the risks of investing all your effort into a job search while just waiting to be fired vs investing in the PIP and ending up being fired anyway with limited job search investment? These risks vary by location, culture, and industry.
As a software developer in Canada, I have an abundance of job opportunities and short tenure isn’t really viewed poorly. Software is in demand in Canada and my specific location of Calgary. To me, job hunting is a low risk choice.
You should also consider whether surviving a PIP is even desirable. Impressions stick. Even if you succeed, you move from person on PIP to person who was on PIP.
In your shoes I would spend all my time job searching. | >
> is this something I can improve on and recover from? Or is it just a
> matter of time before I'm fired, but now they can say I didn't meet
> the conditions of the PIP?
>
>
>
Very often a PIP is just a formality before you are released. But some folks do survive a PIP and go on to be valuable and cherished employees.
Your best bet is to make sure you completely understand specifically what is being asked of you and fulfill it to the best of your abilities, with a good attitude.
It might not work. And to be honest it usually won't. But it won't hurt to try and doing this is really your last chance to stick around.
In addition, working hard to fulfill PIP requirements might get you a decent recommendation from the employer. Just blowing them off almost certainly won't. I know that I personally gave a good recommendation for a worker who tried hard but failed. Being a bad fit for the job I had didn't make her a bad person, nor did it make her a bad fit for her next job.
While on a PIP it certainly makes sense to start up your job-hunting process. Check in with your professional network, and start to see what kinds of jobs are out there for you. |
177,539 | I know this question has probably been asked before, but I'd like some advice from everyone: I'm about to have a PIP (Professional Improvement Plan) drawn up, so is my employment over?
My boss brought up two issues:
1. I wasn't showing "confidence" in client meetings when showing the software updates. Okay, this could be fair.
But what's not fair is that the last client meeting we had was 3 weeks ago! If there was an issue, why didn't my boss bring it up after the meeting? Why did he wait 3 weeks to say something?
When I asked him about this he said I should be more excited and almost act like a salesman towards the client. Okay, this is fair feedback also.
2. On my resume, I said one of my skills is "Fortran", but my resume clearly shows I haven't used it for an employer in about 5 years. My boss complained that he gave me a Fortran issue ticket that I didn't complete in time. Yet I'm rusty on it AND this is the first time that I'm hearing that he's not happy that I'm not working as quickly as he thinks I should.
When I asked him about this, he said he expects people to be masters of everything listed on their resume, even on programming languages they haven't used in years.
The PIP is coming out of the blue with no prior verbal warnings. And I've looked through my hiring agreement and every HR documentation I can find, but nothing mentions the PIP process.
The goals in my PIP includes things like "improve your confidence when presenting at the client meeting" and "improve your Fortran skills". Obviously neither of these has a measurable goal or a specific deadline. Maybe "improve your Fortran skills to finish this ticket in 80% of the allotted time" is a measurable goal, but then why not state this on the PIP?
Some other factors:
* The company seems to be hiring college graduates every few weeks. I take this to mean they have no problem with the time and costs of interviewing and hiring people.
* A possible red flag I only discovered after I started here: the longest person working here has only been here for about 3 years. This means people don't stay long, either because they're fired or they quit.
* I'm approaching 3 months at the company, which is usually a probationary period.
So my question is: is this something I can improve on and recover from? Or is it just a matter of time before I'm fired, but now they can say I didn't meet the conditions of the PIP?
---
As a follow-up:
I had a meeting with my bosses about the PIP process and I wound up putting in my resignation the next day.
In the meeting, I told them that I've already started some classes to improve my skills, but a family emergency came up, and I wouldn't be able to study over the weekend. One boss said he was disappointed that I wasn't making better progress.
The other one pulled up my resume and started going over it, job by job, saying I used Fortran 3 years ago at a previous job and that I used it 6 years ago on a second job. He asked if I was "bigging up my resume" and did I actually know Fortran, or am I just rusty?
As my spouse said, if the boss is pulling out my resume in the middle of the meeting to basically accuse me of lying about my skills, then the business relationship is over. When I said there was a miscommunication about the required skills, the second boss tried to argue that he asked about this in the interview and I said I knew it, so (again) he expected me to be an expert at it. I took this to mean this means it's not their fault for properly vetting the candidate (me) and making sure I could do what's expected, it's my fault for inflating the skills on my resume.
So, thanks to everyone for the advice. | 2021/08/12 | [
"https://workplace.stackexchange.com/questions/177539",
"https://workplace.stackexchange.com",
"https://workplace.stackexchange.com/users/128927/"
] | >
> is this something I can improve on and recover from? Or is it just a
> matter of time before I'm fired, but now they can say I didn't meet
> the conditions of the PIP?
>
>
>
Very often a PIP is just a formality before you are released. But some folks do survive a PIP and go on to be valuable and cherished employees.
Your best bet is to make sure you completely understand specifically what is being asked of you and fulfill it to the best of your abilities, with a good attitude.
It might not work. And to be honest it usually won't. But it won't hurt to try and doing this is really your last chance to stick around.
In addition, working hard to fulfill PIP requirements might get you a decent recommendation from the employer. Just blowing them off almost certainly won't. I know that I personally gave a good recommendation for a worker who tried hard but failed. Being a bad fit for the job I had didn't make her a bad person, nor did it make her a bad fit for her next job.
While on a PIP it certainly makes sense to start up your job-hunting process. Check in with your professional network, and start to see what kinds of jobs are out there for you. | You likely did not meet their expectations
------------------------------------------
Opinions on PIP vary. Some people survive a PIP and become successful in that same company. Somewhere it's just a formality and may not have anything to do with the employee, i.e. company is having financial difficulties and they need to downsize payroll. In some companies they simply do not like the guy and then invent some reasons for PIP and later dismissal.
Now, let's assume they did not hire you in bad faith. There are some companies that actually do that - they promise people a steady job but lay them off after few months. Usually there is some government incentive to do so, and they misuse probation period. However, let's assume they did not do that . Then you gotta ask yourself these questions:
* **Is Fortran big part of your job ?** Or in simple terms, did they hire you to do Fortran ? Your Fortran skills may be a little rusty, but Fortran developers are rare in these times. Maybe they did expect from you to brush up those skills (probably in your own free time) and became full fledged Fortran developer.
* **Is client presentation big part of your job ?** Same as with Fortran. You obviously have fairly large experience (5+ years, as you mentioned). If you are hired as senior developer or even team lead, it could be implicitly expected from you to know how to handle clients. If a company hires lot of recent college grads, maybe they did expect from you to fill managerial role.
If you could honestly answer yes on any of these questions, then it maybe could be worth your while to try and survive your PIP. If the answer is no on both questions, then assume you just landed in a bad company, and start searching for a new job immediately. |
177,539 | I know this question has probably been asked before, but I'd like some advice from everyone: I'm about to have a PIP (Professional Improvement Plan) drawn up, so is my employment over?
My boss brought up two issues:
1. I wasn't showing "confidence" in client meetings when showing the software updates. Okay, this could be fair.
But what's not fair is that the last client meeting we had was 3 weeks ago! If there was an issue, why didn't my boss bring it up after the meeting? Why did he wait 3 weeks to say something?
When I asked him about this he said I should be more excited and almost act like a salesman towards the client. Okay, this is fair feedback also.
2. On my resume, I said one of my skills is "Fortran", but my resume clearly shows I haven't used it for an employer in about 5 years. My boss complained that he gave me a Fortran issue ticket that I didn't complete in time. Yet I'm rusty on it AND this is the first time that I'm hearing that he's not happy that I'm not working as quickly as he thinks I should.
When I asked him about this, he said he expects people to be masters of everything listed on their resume, even on programming languages they haven't used in years.
The PIP is coming out of the blue with no prior verbal warnings. And I've looked through my hiring agreement and every HR documentation I can find, but nothing mentions the PIP process.
The goals in my PIP includes things like "improve your confidence when presenting at the client meeting" and "improve your Fortran skills". Obviously neither of these has a measurable goal or a specific deadline. Maybe "improve your Fortran skills to finish this ticket in 80% of the allotted time" is a measurable goal, but then why not state this on the PIP?
Some other factors:
* The company seems to be hiring college graduates every few weeks. I take this to mean they have no problem with the time and costs of interviewing and hiring people.
* A possible red flag I only discovered after I started here: the longest person working here has only been here for about 3 years. This means people don't stay long, either because they're fired or they quit.
* I'm approaching 3 months at the company, which is usually a probationary period.
So my question is: is this something I can improve on and recover from? Or is it just a matter of time before I'm fired, but now they can say I didn't meet the conditions of the PIP?
---
As a follow-up:
I had a meeting with my bosses about the PIP process and I wound up putting in my resignation the next day.
In the meeting, I told them that I've already started some classes to improve my skills, but a family emergency came up, and I wouldn't be able to study over the weekend. One boss said he was disappointed that I wasn't making better progress.
The other one pulled up my resume and started going over it, job by job, saying I used Fortran 3 years ago at a previous job and that I used it 6 years ago on a second job. He asked if I was "bigging up my resume" and did I actually know Fortran, or am I just rusty?
As my spouse said, if the boss is pulling out my resume in the middle of the meeting to basically accuse me of lying about my skills, then the business relationship is over. When I said there was a miscommunication about the required skills, the second boss tried to argue that he asked about this in the interview and I said I knew it, so (again) he expected me to be an expert at it. I took this to mean this means it's not their fault for properly vetting the candidate (me) and making sure I could do what's expected, it's my fault for inflating the skills on my resume.
So, thanks to everyone for the advice. | 2021/08/12 | [
"https://workplace.stackexchange.com/questions/177539",
"https://workplace.stackexchange.com",
"https://workplace.stackexchange.com/users/128927/"
] | **Opinions differ on whether PIPs are just "you're fired!, but I don't have the paperwork yet" or not**
Whether PIPs are survivable differs significantly by company and no consensus opinion on whether you you should try and survive a PIP exists.
Nobody here can know whether this particular PIP is survivable besides your own manager. Nor is it a general corporate standard that PIPs can be survived.
This ambiguity forces you to look at it from a risk perspective. What are the risks of investing all your effort into a job search while just waiting to be fired vs investing in the PIP and ending up being fired anyway with limited job search investment? These risks vary by location, culture, and industry.
As a software developer in Canada, I have an abundance of job opportunities and short tenure isn’t really viewed poorly. Software is in demand in Canada and my specific location of Calgary. To me, job hunting is a low risk choice.
You should also consider whether surviving a PIP is even desirable. Impressions stick. Even if you succeed, you move from person on PIP to person who was on PIP.
In your shoes I would spend all my time job searching. | You likely did not meet their expectations
------------------------------------------
Opinions on PIP vary. Some people survive a PIP and become successful in that same company. Somewhere it's just a formality and may not have anything to do with the employee, i.e. company is having financial difficulties and they need to downsize payroll. In some companies they simply do not like the guy and then invent some reasons for PIP and later dismissal.
Now, let's assume they did not hire you in bad faith. There are some companies that actually do that - they promise people a steady job but lay them off after few months. Usually there is some government incentive to do so, and they misuse probation period. However, let's assume they did not do that . Then you gotta ask yourself these questions:
* **Is Fortran big part of your job ?** Or in simple terms, did they hire you to do Fortran ? Your Fortran skills may be a little rusty, but Fortran developers are rare in these times. Maybe they did expect from you to brush up those skills (probably in your own free time) and became full fledged Fortran developer.
* **Is client presentation big part of your job ?** Same as with Fortran. You obviously have fairly large experience (5+ years, as you mentioned). If you are hired as senior developer or even team lead, it could be implicitly expected from you to know how to handle clients. If a company hires lot of recent college grads, maybe they did expect from you to fill managerial role.
If you could honestly answer yes on any of these questions, then it maybe could be worth your while to try and survive your PIP. If the answer is no on both questions, then assume you just landed in a bad company, and start searching for a new job immediately. |
204,659 | In 3.5, the epic rules rules
state that no new spell slots
are obtained after level 20. But if a 20th level wizard, say, picks up a level of cleric to get to level 21 (20 Wiz 1 Clr) does that character get new cleric spells? | 2023/02/11 | [
"https://rpg.stackexchange.com/questions/204659",
"https://rpg.stackexchange.com",
"https://rpg.stackexchange.com/users/80598/"
] | The *Dungeon Master's Guide* in its section **Epic Characters** (206–10) on [**Epic Class Features**](http://dndsrd.net/epicLevels.html#class-features), in part, says that a "character’s spells per day don't increase after 20th level" (207). This clearly contradicts [**Adding a Second Class**](http://dndsrd.net/epicLevels.html#adding-a-second-class) that, in part, says
>
> **When an epic character** with levels in only one class **attains a new level**, **she may choose to** increase the level of her current class or **pick up a new class at 1st level.** The standard rules for multiclassing… still apply….
>
>
> **An epic character gains the** class skills, weapon proficiency, armor proficiency, **spells**, and other class features **of the new class**, as well as a Hit Die of the appropriate size. In addition, the character gets the usual skill points from the new class.
>
>
> Just as with standard multiclassing, adding the second class does not confer some of the benefits for a 1st-level character, including maximum hit points from the first Hit Die, quadruple the per level skill points, starting equipment, starting gold, or an animal companion.
>
>
> An epic character does not gain the base attack bonuses and base save bonuses normally gained when adding a second class. Instead, the character uses the epic attack bonus and epic save bonus progression shown on Table 6–18: Epic Save and Epic Attack Bonus. (207 and emphases mine)
>
>
>
Yes, those are on the same page. Here's the double-think: In that quotation from the Epic Class Features section, the *DMG* is discussing an epic creature that already has all of one class's nonepic spells per day; that character normally sees no increase in spells per day by advancing more in that class. (Other game elements, obviously, can increase.)
* **Example 1:** A cleric 20 who advances to cleric 21 doesn't see an increase in her spells per day solely *because* she advanced from cleric 20 to cleric 21.
* **Example 2:** A druid 20/fighter 4 who advances to druid 21 doesn't see an increase in her spells per day solely *because* she advanced from druid 20 to druid 21.
In the quotation from Adding a Second Class, the *DMG* is discussing an epic creature that opts to gain a new spellcasting class. Such a creature gets spells per day for taking that new class's first level, and that creature will see an increase in that class's spells per day as that creature advances that class's spellcasting until the creature reaches that class's maximum nonepic spells per day for that class. This is usually at class level 20 but exceptions like some prestige classes are frequent.
(This ruling, by extension, should apply to any epic creature that has less than full nonepic spellcasting in a class. For example, a cleric 30/wizard 25 who takes a level of dread necromancer gets dread necromancer spells per day as a dread necromancer 1 and can thereafter increase her dread necromancer spells per day (by advancing levels in dread necromancer or a prestige class that advances dread necromancer spellcasting) until she reaches level 20 in dread necromancer spellcasting.)
* **Example 3:** A cleric 20 who becomes a cleric 20/wizard 1 *does* get *new* wizard spells per day from being a wizard and can advance wizard spells per day until the creature advances to cleric 20/wizard 20. However, at cleric 21 or higher or wizard 21 or higher, the creature's spells per day typically don't increase.
* **Example 4:** A cleric 20/wizard 15/druid 3 who takes levels in the prestige class [**mystic theurge**](http://dndsrd.net/mysticTheurge.html#_top) (192–3) can apply the class feature **+1 level of existing arcane spellcasting class** to her wizard class, but if she does that then she has wizard spellcasting 21 or higher, and she doesn't see an increase in wizard spells per day. She can apply can apply the class feature **+1 level of existing divine spellcasting class** to her cleric or druid class, but if she picks the former she doesn't see an increase in spells per day by advancing her effective cleric spellcasting from level 20 to 21. However, she would see in an increase in her druid spells per day were she to pick the latter.
It's possible to read this in different ways, perhaps by ignoring one quotation or the other, but doing so tends to run against the game's own examples. High Lady of Silverymoon **Alustriel** (*Epic Level Handbook* 300–1), for instance, is, among other things, a Wiz20/Sor2 yet still has sorcerer spells per day, and former Chosen of Gilgeam **Shuruppak** (305) is a Ftr20/Rog3/Wiz7 yet still prepares wizard spells. While examples aren't rules and the rules could be clearer, the epic level characters the game describes follow the processes described above. | **YES** an epic character continues to earn new spells when leveling a class that is not yet level 20.
This is the section causing confusion (from [Epic Level Basics: Class Features](http://dndsrd.net/epicLevels.html#class-features)):
>
> For spellcasters, caster level continues to increase after 20th level. However, spells per day don’t increase after 20th level. The only way to gain additional spells per day (other than the bonus spells gained from a high ability score) is to select the Improved Spell Capacity epic feat.
>
>
>
However, that section is specifically regarding class, not character, progression. As stated before the bullet points:
>
> Many, but not all, class features continue to accumulate after 20th level. The following guidelines describe how the epic **class** [emphasis added] progressions.
>
>
>
The rule is stating that progressing a spell-casting *class* beyond level 20 does not garner additional spell slots. |
124,152 | I have a location in my story, the design of which needs a reality check.
**City Description:**
>
> As my ship cut across the waves a blurred grey smudge appeared in the distance, as the hours passed it became more distinct and it's true scope came into view.
>
>
> As we neared the end of our voyage a great cliff of jagged granite rose hundreds of feet from the relentlessly pounding sea and spread as far as the eye could see in either direction. The tops of the tallest buildings shining brightly in the moonlight peered down from atop the cliff. The face of the cliff, littered with windows glowed like the eyes of fey forest creatures and large towers ascended at intervals striped like a barber pole apparently carved from the face of the cliff.
>
>
> Directly before us a giant maw opened in the cliff the top jagged like the mouth of some vicious predator. On either side of the cliff massive braziers burned brightly in the night.
>
>
>
There is more to the poetic description but I think that is sufficient to set the feel for the place.
**City Details:**
* The city is built into, and on top of, a granite cliff. The cliff rises 500' (152 Meters) from the sea below.
* The granite cliff extends perhaps a mile in either direction (this can be adjusted somewhat if it matters) and should extend at least 1500' (460 M) inland.
* In the face of the cliff is a large cavern that can accommodate large two masted sailing ships. Tugs are used to tow the ships to docks within the cave.
* Inside there are stairways and elevators (both for people and cargo) that lead up to the surface.
* Inside the rock formation I am looking for enough space for approximately 1000 residents, each should be afforded 12'x 12' (.305 x .305 M) of floor space, dwellings are not all the same size.
* Living spaces are reminiscent of Bag End from The Fellowship of the Ring, though scaled for a normal human to walk without doubling over (8' ceilings) The underground portion will also require space for cargo storage.
* Atop the rock face is a city, where important structures are built from the excavated granite and lesser structures from both stone and wood from the surrounding forest.
**Points of consideration for the reality check.**
* Can this much granite exist in one place, are there real world examples?
* Does the described amount of excavation seem possible or would it cause structural problems? (Faults can be set however structurally required)
* Are there examples of dwellings carved into granite in the real world for the purpose of habitation?
* Are there concerns with this setup that I have not considered? | 2018/09/04 | [
"https://worldbuilding.stackexchange.com/questions/124152",
"https://worldbuilding.stackexchange.com",
"https://worldbuilding.stackexchange.com/users/189/"
] | Granite Massifs are common
--------------------------
A granite block of the size you ask for is totally feasible. El Capitan in California is certainly taller.
Getting the living spaces you want without explosives or magic is going to be sufficiently expensive to be impossible. Cutting stone by hand takes a long long time. From personal experience, with a hammer drill and modern drill bits, it took the better part of an hour to cut a single row of holes about 6" deep. Medieval miners with poor quality iron or steel will take days or weeks to cut the same set of holes. To excavate the amount of material described will take forever.
Making granite "caves" is usually done artificially by cutting up the rock into blocks then forming it into buildings. As most caves are found in rock types that dissolve in water and granite does not, some other mechanism will need to be used to create the voids in the rock.
Without a very secure bay to protect the cave mouth, no captain will risk their ship. The scene describes pounding surf indicating that the cliff face extends far below the water line. While the deep water will allow large ships to approach the cave mouth, and even enter, no one would dock their ship there.
Depending on the shape of the cave and without a harbor, the waves in the cave could frequently be larger than the waves outside. Big waves on the open ocean aren't too bad. Big waves are really bad when your ship can be thrown against a cliff face, even if that face is in a cave.
Compare paintings of the docking density between the Thames River in the 1800s vs Boston Harbor. The Thames is absolutely packed! Why? Because conditions on the Thames are very placid. The risk of one ship inadvertently running into another was low enough that the density of docked ships could increase. Boston harbor doesn't have those kind of conditions. Thus, to prevent accidents, boats are anchored much further away from each other.
Ignoring the waves, the tides will put a limit on the maximum height of the ships that will fit in your cave. Assuming a normal earth-moon system, tides may vary by as much as 3 meters. | Actually granite rarely form caves, and never that big. Water erode the rock by infiltrating through the faults producing sand and large blocks but no cave. Nonetheless there are huge granite cliffs in Yosemite like the Half Dome. You can't really dig into granite, may be a stairway would be possible on the face of the cliff. Building with granite is possible you even have lighthouses made of this.
On the other hand, compact lilestone suits perfectly, but it is completely white and a port in a cave is still dangerous. |
94,883 | What is a verb for *illusion*? I want to use it in a sentence like the following:
>
> The optical effect [illudes] my perception of its real shape.
>
>
>
But **illude** does not exist. But I cannot find *illude* in my Dictionary (OS X Dictionary.app). I want to find a verb that is somewhere between *deceive* and *confuse*. | 2012/12/20 | [
"https://english.stackexchange.com/questions/94883",
"https://english.stackexchange.com",
"https://english.stackexchange.com/users/9976/"
] | Um, what do you mean “*illude* does not exist”? Sure it does. It’s just a tad rare these days. From the OED:
>
> **illude** /ɪˈl(j)uːd/, *v.* Now *rare*.
>
>
> Also 6 **illud**.
>
>
> Etymology: ad. L. *illūdĕre* to make sport of, jest or mock at, ridicule, occas. to trick, impose upon, f. *il-* (**il-**1) + *lūdĕre* to play. Cf. obs. Fr. *illuder* (Godef.).
>
>
> **† 1.** *trans.* To mock, make sport of, deride. *Obs*.
>
> **2.** To trick, impose upon, deceive with false hopes.
>
>
>
There a bit more than that, but those other senses are not used any longer; only #2 is. Here are some citations to go with it:
>
> * 1670 G. H. *Hist. Cardinals* ɪɪɪ. ɪɪɪ. 293 ― Full of hypocrisie and dissimulation, to lull and illude one another.
> * 1872 M. Collins *Two Plunges for Pearl* I. iii. 64 ― They had allowed their imaginations to illude them.
>
>
>
They also mention the forms *illuded* and *illuding*; for example:
>
> * 1745 Warton *Pleas. Melanch.* 185 ― The woodman’s stroke, or distant tinkling team··alarms The illuded sense.
> * 1887 *Athenæum* 3 Dec. 745/1 ― They [women] come across unfavourable specimens of the illuding sex.
>
>
>
I’m not saying that you’re apt to skate on entirely thick ice if you were to use these, but *illude* certainly **DOES** “exist”, and means pretty much what you would think it means. | I might use the word *obscures* in that sentence:
>
> The optical effect obscures my perception of its real shape.
>
>
>
From [Oxford Dictionaries](http://oxforddictionaries.com/definition/english/obscure): "obscure (verb): Keep from being seen; conceal". |
94,883 | What is a verb for *illusion*? I want to use it in a sentence like the following:
>
> The optical effect [illudes] my perception of its real shape.
>
>
>
But **illude** does not exist. But I cannot find *illude* in my Dictionary (OS X Dictionary.app). I want to find a verb that is somewhere between *deceive* and *confuse*. | 2012/12/20 | [
"https://english.stackexchange.com/questions/94883",
"https://english.stackexchange.com",
"https://english.stackexchange.com/users/9976/"
] | Interesting question.
How about **"deceive"** or **"mislead"**? But I am not sure if you can replace "illudes" with either of these in the sentence you have given. | Perhaps too extreme, but *perverts* might work. Or better maybe, *subverts*. |
94,883 | What is a verb for *illusion*? I want to use it in a sentence like the following:
>
> The optical effect [illudes] my perception of its real shape.
>
>
>
But **illude** does not exist. But I cannot find *illude* in my Dictionary (OS X Dictionary.app). I want to find a verb that is somewhere between *deceive* and *confuse*. | 2012/12/20 | [
"https://english.stackexchange.com/questions/94883",
"https://english.stackexchange.com",
"https://english.stackexchange.com/users/9976/"
] | Um, what do you mean “*illude* does not exist”? Sure it does. It’s just a tad rare these days. From the OED:
>
> **illude** /ɪˈl(j)uːd/, *v.* Now *rare*.
>
>
> Also 6 **illud**.
>
>
> Etymology: ad. L. *illūdĕre* to make sport of, jest or mock at, ridicule, occas. to trick, impose upon, f. *il-* (**il-**1) + *lūdĕre* to play. Cf. obs. Fr. *illuder* (Godef.).
>
>
> **† 1.** *trans.* To mock, make sport of, deride. *Obs*.
>
> **2.** To trick, impose upon, deceive with false hopes.
>
>
>
There a bit more than that, but those other senses are not used any longer; only #2 is. Here are some citations to go with it:
>
> * 1670 G. H. *Hist. Cardinals* ɪɪɪ. ɪɪɪ. 293 ― Full of hypocrisie and dissimulation, to lull and illude one another.
> * 1872 M. Collins *Two Plunges for Pearl* I. iii. 64 ― They had allowed their imaginations to illude them.
>
>
>
They also mention the forms *illuded* and *illuding*; for example:
>
> * 1745 Warton *Pleas. Melanch.* 185 ― The woodman’s stroke, or distant tinkling team··alarms The illuded sense.
> * 1887 *Athenæum* 3 Dec. 745/1 ― They [women] come across unfavourable specimens of the illuding sex.
>
>
>
I’m not saying that you’re apt to skate on entirely thick ice if you were to use these, but *illude* certainly **DOES** “exist”, and means pretty much what you would think it means. | The tricks **baffle**, the performance **astonishes**, **amazes** and **astounds**. It's **magical** and **mystifying** but it includes **misdirection**. |
94,883 | What is a verb for *illusion*? I want to use it in a sentence like the following:
>
> The optical effect [illudes] my perception of its real shape.
>
>
>
But **illude** does not exist. But I cannot find *illude* in my Dictionary (OS X Dictionary.app). I want to find a verb that is somewhere between *deceive* and *confuse*. | 2012/12/20 | [
"https://english.stackexchange.com/questions/94883",
"https://english.stackexchange.com",
"https://english.stackexchange.com/users/9976/"
] | Obfuscate can work.
1. to confuse, bewilder, or stupefy.
2. to make obscure or unclear: to obfuscate a problem with extraneous information.
3. to darken. | The tricks **baffle**, the performance **astonishes**, **amazes** and **astounds**. It's **magical** and **mystifying** but it includes **misdirection**. |
94,883 | What is a verb for *illusion*? I want to use it in a sentence like the following:
>
> The optical effect [illudes] my perception of its real shape.
>
>
>
But **illude** does not exist. But I cannot find *illude* in my Dictionary (OS X Dictionary.app). I want to find a verb that is somewhere between *deceive* and *confuse*. | 2012/12/20 | [
"https://english.stackexchange.com/questions/94883",
"https://english.stackexchange.com",
"https://english.stackexchange.com/users/9976/"
] | Obfuscate can work.
1. to confuse, bewilder, or stupefy.
2. to make obscure or unclear: to obfuscate a problem with extraneous information.
3. to darken. | You could use *illusory*, which is an adverb. |
94,883 | What is a verb for *illusion*? I want to use it in a sentence like the following:
>
> The optical effect [illudes] my perception of its real shape.
>
>
>
But **illude** does not exist. But I cannot find *illude* in my Dictionary (OS X Dictionary.app). I want to find a verb that is somewhere between *deceive* and *confuse*. | 2012/12/20 | [
"https://english.stackexchange.com/questions/94883",
"https://english.stackexchange.com",
"https://english.stackexchange.com/users/9976/"
] | I think *[confounds](http://dictionary.reference.com/browse/confound?s=t)* is often used in this context.
>
> The optical effect **confounds** my perception of its real shape.
>
>
>
It has a nice feel of causing consternation without deceitfulness or the sort of blundery feel you get from "confuse." And whereas people tend to be confused, senses are confounded in [literature](http://www.google.com/search?q=confound+the+senses&btnG=Search+Books&tbm=bks&tbo=1). | >
> The optical effect **dazzles** my perception of its real shape.
>
>
>
[dazzle:](http://www.merriam-webster.com/dictionary/dazzle) to lose clear vision especially from looking at bright light |
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