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where did the idea that classical music makes infants smarter come from, and has it been proven? | There was a study that showed pretty well that listening to music made adults temporarily better at doing a spatial reasoning paper folding task.
This sort of melted into "classical music only specifically makes people smart" to "classical music makes babies smart". It's some pretty big leaps from the original study. | [
"Felix Carrasco is aware of the importance of early approach of classical music to children. This is why this project was entirely thought for them. Beautiful stories such as Peter and the Wolf (Prokofiev), Carnival of the Animals (Saint-Saëns), and The Young Person's Guide to the Orchestra (Britten) are included i... |
marvel movie rights distribution | [Infographic courtesy of The Geek Twins.](_URL_0_)
I *think* the reason Marvel are OK with using Scarlet Witch and Quicksilver is that they're both X-Men characters and members of the Avengers, but I'm not sure.
The whole arrangement is because of Marvel trying to push out into TV and film from the 70's onwards and deciding the best way to do that was to offer other companies exclusive license to film a certain character/group and their major plotlines. This way they didn't have to put a lot of money on the line themselves, while still standing to gain from movies drawing in new fans of the characters. With the creation of Marvel Studios in 1996 they've moved to actively producing movies themselves, but many of those licenses are still around. They can't use those characters or tie them into the greater Marvel cinematic universe now without the permission of their licensees (who'd likely want *a lot* of money for it). As such their universe of characters has become a bit fragmented on screen.
As you say, many of these license agreements expire if the licensees don't produce a film with them for a long enough time. [Here](_URL_1_) is a quote about prospects for that in the future from Marvel Studios head Kevin Feige:
> The contracts are all very specific, and if there is ever a time for them to revert, they will. But right now they are safely at those studios. | [
"Meanwhile, Marvel Entertainment Group, Inc. was in such dire financial straits that they sold off their characters' film rights to several major movie studios, including Universal Pictures. MCA then eventually negotiated with Marvel for the theme park rights to their characters and both companies signed an agreeme... |
what is a "startup" company and how do they work? what is the employee/department structure like? | - A startup could have been formed last week or 4 years ago.
- They could be working in a garage out of a $1000 investment from a founder, or a 5 million venture capital they painstakingly raised over several rounds of financing after showing steady improvements and meeting the targets they promised they would.
- They could have 2 people working 100 hours a week each and creating a web app, or 50 people working 100 hours a week each and creating the world's first commercial space shuttle.
- Ideally the startup is "flat" and devoid of heirarchy. The CEO can regularly cleans out the sink and loads the dishwasher. The engineer also signs for Fedex deliveries and keeps the bathroom tissue stocked. The intern spends his day helping with market research and making databases of prior patents, competition etc. Come lunch, every one lunches together and discusses their weekend, the game next month, or the concert last week.
- Dressing is usually casual - jeans, t-shirt, sneakers...sometimes even shorts.
- Focus is on getting your product launched successfully or pleasing a customer, and little importance is given to exactly how many hours you logged in a week. In the same token, startups are more flexible when it comes to employees taking time off. With more freedom comes greater accountability.
- There is a no set path, no formal document that guides you to a certain new process. You explore a lot and frequently have to create a document out of scratch so that future employees down the line may benefit from it.
- Pay usually does not match a comparable job in a Fortune 500 company. However they do make it up by offering stocks. The earlier you join a startup, the more risk you take, therefore the larger chunk of the equity you could hope to bargain for.
Hope this helps. Ask any specific questions. Will be happy to help. | [
"Internal startups are a form of corporate entrepreneurship. Large or well-established companies often try to promote innovation by setting up \"internal startups\", new business divisions that operate at arm's length from the rest of the company. Examples include Bell Labs, a research unit within Bell Corporation ... |
What sort of toys did Roman children play with? | Balls were very popular (usually inflated bladders). This example is Greek, but I believe the scene in the Odyssey in which Odysseus washes up on shore and Nausicaa is playing ball with her companions is the oldest mention of a ball game in western literature.
Children also commonly played with dolls and carved toys and rattles and dice. The Metropolitan Museum of Art has some ancient toys in their collection. Many museums with classical collections have examples of these toys. | [
"Roman children had different clothing from adults until they came of age or were married. Children’s education was normally practiced at home. When children were not being educated their play time consisted of a variety of toys such as rattles, dolls made of cloth, clay, or wax, toy weapons, letter blocks, tops, b... |
I heard that jupiter is a failed star due to not being massive enough to start a fusion reaction. If this is true, can we detonate a fusion bomb on the planet to start a chain reaction? | Nope, because Jupiter is far from being a failed star. For an object to be a star, it has to have at least 75 jupiter masses, because only then it could have a permanent hydrogen fusion. Objects with lower mass may have deuterium/lithium fusion and are called brown dwarfs. They are in the range of about 13 - 75 jupiter masses. Everything below is a planet or a planetary mass object, if it has no home star. They don't support any kind of fusion and won't ignite even with the help of a nuke. | [
"In massive stars, fusion continues until the iron core has grown so large (more than 1.4 ) that it can no longer support its own mass. This core will suddenly collapse as its electrons are driven into its protons, forming neutrons, neutrinos, and gamma rays in a burst of electron capture and inverse beta decay. Th... |
What pre-modern examples are there of movements for racial equality? (more generally, political/legal economy of ethnic groups) | During the era of the Roman Republic, citizen rights were only granted to people of Roman birth and heritage. Even Rome's closest allies - the other Italian cities - were not granted citizenship.
There was a lot of discontent people as those cities had been allied with Rome for hundreds of years, and were instrumental in it's rise to power. Yet they were not treated as equals.
This culminated in the [Social War](_URL_0_), which was a war with Rome fighting a dozen other Italian city states. This can be considered a move for racial equality because of two main reasons:
Italy at this time was not a homogeneous culture. Most Italic cities still had their own regional language/dialects and tradition, notably the Marsics and the Samnites who were the main belligerents of this war.
The city states were fighting a war of secession, but it wasn't exactly one of independence. The cities wanted to form a confederation that operated almost exactly the same as the Roman Republic - they even borrowed many parts of their constitution.
Basically, they decided that if the Romans wouldn't let them be equal citizens of their republic, they would form their own republic which would operate exactly the same as the Roman one, with the key difference that they were citizens and accorded the rights and laws that were denied to them under while under Roman rule.
The war ended with a Roman military victory, but Rome was forced to concede rights to the Italian client cities in order to end the war quickly so their legions were freed up to fight rebellions in the East. | [
"Over time, it has changed in fundamental ways the manner in which blacks and whites interact with and relate to one another. The movement resulted in the removal of codified, \"de jure\" racial segregation and discrimination from American life and law, and heavily influenced other groups and movements in struggles... |
When you connect a voltage to a wire, how long will it take for it to be observable on the other end of the wire? Does the voltage propgate via electrons at the speed of light? Or is it slower? | Practically, it is slower than the speed of light, because of the capacitance of the wire (which is very roughly about 10pF a foot, depending on the wire). With long, fine/high resistance wires, this can make for a significant filter. But in a theoretical, frictionless, vacuum world, one often says it happens at the speed of light.
But it's worth mentioning that the delay cause by these so called parasitic capacitance are real and significant in computing. Indeed, it is my understanding that the delay even if there was zero capacitance, i.e. just the speed of light is an important and relevant limit in the designs of CPUs. That is to say, it would take about 30 picoseconds for light to travel from one end of a CPU to the other. That limits the speed of a CPU to 30 gigahertz. While that is a way away from modern CPU limits, it's not really THAT far at all.
P.S. just for the pedants. Yes, I know the gate capacitance of the transistors is far far more important, but still, the point was to illustrate that the speed of light, while fast, is actually getting kinda slow for modern computing. | [
"The interesting consequence of this behavior is that, while a single 2 mm length of wire has a delay of 4 µs, two separate 1 mm wires only have a delay of 1 µs each. The two separate wires cover the same distance in half the time! By cutting the wire in half, we can double its speed.\n",
"The time it takes for a... |
how come even though imgur's servers are over capicated quite a few times a day, we are still able to view them on reddit? | Rendering the PHP code and performing the SQL queries to dynamically render the Imgur site takes a lot of processing power. Their service provider will redirect to the Over Capacity page automatically if they are exceeding their allocated processor utilization. With a direct image URL, none of that needs to happen, it's just simply replying and transmitting some data. | [
"Imgur used to have a policy to keep images unless they went three months without receiving any views, at which point (unless they were Pro account images) they might be removed in response to space needs. In early 2015 it was announced all images will be kept forever (even if not added from a Pro account) and only... |
why hasn't the catholic church reported all of the priests with alleged child abuse charges to their local authorities? | So hopefully mine or someone else's level headed comment will get through the typical reddit bullshit.
So forget about the bad press. The bad press has already happened. They aren't saving an image as much as they straight up don't know what to do.
What would you do? A massive chunk of your organization starts doing sick things to children and its all really coming to light within a matter of 100 years or so.
I can't think of a similar instance in human history, where a group of people suddenly have something so crazy on their hands. I'd be dumbstruck.
**Now here is another big part of it**
They are running out of priests. If you don't have a priest at the Parish, then who says Mass, who works in the community, who blesses the sacrament?! They already have Priests here in the states who are not only the "head" Pastor for their church but the head pastor for 3 or more! They have several hour long commutes throughout the week.
Priest numbers keep going down, if they let this huge chunk of pedophiles go, then they see churches and the faithful go to.
Nobody has any real numbers on this stuff from the Vatican's point of view. There was never a book with a tally or a directory of the pedophiles. So there already fucked when it comes to fixing the problem. They have no way of knowing ALL of the pedophiles and rapists.
So I guess there are 3 reasons:
**They don't have the resources or knowledge to combat such an epidemic**
**They are hemorrhaging Priests, anything negative to being a priest (i.e. a good amount have been doing sick stuff) isn't exactly a good method of gaining more.**
**Where do they even begin? There are so many different countries laws and different cases. This is so far beyond the scale of "turn everyone in Pope!" it is now more like "Pope you have a real issue in the clergy, not only do we need action now but you have to cut this off at the source."** | [
"Several priests who abused children in the United States were Irish National, notably Patrick Colleary, Anthony O'Connell and Oliver O'Grady. In August 2018, a list was published which revealed that over 1,300 Catholic clergy in Ireland had been accused of sexual abuse, with 82 of them getting convicted.\n",
"On... |
At what stage do people typically "feel" cancer? How is it possible for someone to just get diagnosed at stage 4, at that point of metastasization shouldn't the person be in massive pain at stage 3 already? | There's no answer to this as it is vastly vastly different between any of the 200+ types of cancer, and even within a type it can depend on where exactly the tumor is.
For example, the most common subtype of Non-Hodgkin Lymphoma shows up as a very rapidly growing lymph node in the neck or chest (over a few weeks). It can grow so quickly that you end up with serious problems from the size of the tumor, and if you're not treated you die in less than a year. The second most-common subtype of Non-Hodgkin lymphoma grows so slowly you might not experience any symptoms for years, and it's only noticed when a doctor feels that you have a small lump somewhere. People can survive for 10+ years. That's two subtypes of the "same" cancer!
Pancreatic cancer is a really nasty one because there are usually no symptoms--or very nonspecific ones--until it's grown large enough that treatment has become just about impossible. A colonoscopy does **not** detect pancreatic cancer. In order to "see" the tumor, you have to get an ultrasound, abdominal CT scan, or MRI--none of which are recommended to get routinely. | [
"People who have finished cancer treatment often have psychological and physical medical challenges. These effects can vary from person to person, change over time, and range in intensity from mild and intermittent to fully disabling. They commonly include fatigue, pain, sleep problems, physical side effects like l... |
What was it like to run a family restaurant in south in 1960 if you were not a racist and wanted to serve everyone who walks in through the door as best you can? | Don't forget that before the Civil Rights Act of 1964, Southern cities such as Atlanta and New Orleans segregated their restaurants by law. For example, Section 369 of the Birmingham, Alabama Racial Segregation Ordinances contained the following clause:
> It shall be unlawful to conduct a restaurant or other place for the serving of food in the city, at which white and colored people are served in the same room, unless such white and colored persons are effectually separated by a solid partition extending from the floor upward to a distance of seven feet or higher, and unless a separate entrance from the street is provided for each compartment.
So, far from being a matter of economic pressure, serving a black person in a white restaurant put you in violation of the law.
Of course, most jurisdictions in the South did not have formal Jim Crow laws related to restaurants, but in those cases segregation was enforced through custom, and backed by violence. Before the Civil Rights Movement, few blacks would have had the courage - or recklessness - to test these rules. The few examples I'm aware of involve black soldiers during World War II, most of whom were beaten - several veterans recalled being chased out of restaurants with a baseball bat - or manhandled by Military Police.
So in many ways your question is moot, since the regime of terror that existed in the segregated South made this kind of behavior unthinkable.
Note as well that most of these rules also applied to the North - [most restaurants in New York City in the early 1960s discriminated against black customers](_URL_1_) - and black travellers required the assistance [the Green Book](_URL_0_) to find the very few restaurants and hotels that would offer them service, regardless of which part of the US they found themselves.
| [
"Integrating lunch counters in the Southern United States through the use of sit-in political protests in the 1960s was a major accomplishment of the Civil Rights Movement. These involved African Americans and their supporters sitting at the lunch counter in areas designated for \"whites only\", insisting that they... |
why is there a certain smell to really cold freezers? | The refrigerant is odorless ( _URL_0_ ). You're most likely smelling something resulting from the accumulation of moisture, the food, packaging, etc. | [
"The experience of eating favored foods with a cold often disappoints. This is because congestion blocks nasal passageways through which air and flavor molecules enter and exit, thus temporarily reducing retronasal smell capacity.\n",
"A cold chill (also known as chills, the chills or simply thrills) is described... |
Would a pool of water protect you from the pressure wave and fiery heat of a bomb's explosion? | The water may offer some protection from an explosion occurring above it since part of the pressure wave is reflected as it hits the surface. It would also quench fires and keep you cool, preventing fatal burns.
In addition, most of the fatalities from explosions tend to be due to shrapnel flying away from it and tearing through your body. Since water is much denser than air, this shrapnel tends to slow down much quicker in water. In fact just a meter or two of water would stop the bullets from almost all light firearms, even though such projectiles can easily be fatal at several hundred meters in air. | [
"BULLET::::- Mass and incompressibility (all explosions) – water has a much higher density than air, which makes water harder to move (higher inertia). It is also relatively hard to compress (increase density) when under pressure in a low range, say up to 100 atmospheres. These two together make water an excellent ... |
what determines the cc of an engine? what makes a bike 250cc vs. 500cc also why is a higher cc faster(typically)? | It's a measure of volume in **c**ubic **c**entimeters that the pistons in the engine can displace. Very simply put, bigger engines are more powerful. | [
"The categories based on engine size frequently use the following thresholds of engine capacity: 0-50cc, 66-85cc, 85-100cc, 124cc-200cc, 201-250cc, and larger than 250cc. Accordingly, a beginning rider on a 200cc motorcycle would likely compete in the 200C class, which denotes both the capacity of his or her motorc... |
why is it that the nations of the commonwealth (canada, uk, australia, etc.) do not have the same traveling protocol as, say, the eu? why can't citizens of commonwealth nations travel into other commonwealth nations without showing passports, etc? | Simply because there is no agreement between the commonwealth countries that would allow that. Despite being linked by history and a queen, they are still different countries and a travel agreement would require lots of negotiating and back and forth and so on. | [
"Like the TWOV rules of other countries, travelers must be in transit to a different country other than the country of departure, hence passengers who travel between the U.S. territories and contiguous United States, Alaska or Hawaii are ineligible for TWOV, unless one of their flights has a stop in another country... |
why are 'geniuses' always good at math? | It honestly depends how you view geniuses.
If like a lot of people you think geniuses dont simply have to be very smart and have a high IQ. For example if you think people can be lyrical geniuses or comedic geniuses etc. Than they likely wont be good at math.
If you are only talking about smart people they are likely good at math because its just numbers and formulaes etc. You can learn the basics from a young age and perfect it while your brain is still very fresh and open this is why high IQ is usually born instead of made. As well as this its a fundamental part of life, you will always need math in life but other school stuff is less important
| [
"A view associated with Francis Galton author of \"Hereditary Genius\" (1869). suggests that \"when asked to explain why some children do better in math than others, Asian children, their teachers, and their parents point to hard work, their American counterparts to ability.\"\n",
"Genius (also known as the Geniu... |
Is the gravitational pull of an object the same as the sum of the gravitational pull of the atoms that make up that object? | Practically speaking, yes. If you look at the Newtonian theory of gravity, that is exactly what happens, and the Newtonian theory is close enough to the truth on the level you are describing. If you look at really massive objects (like neutron stars) then the Newtonian theory is no longer accurate and you need General Relativity. I'm not sure what the answer is in that case. | [
"In this way, it can be shown that an object with a spherically-symmetric distribution of mass exerts the same gravitational attraction on external bodies as if all the object's mass were concentrated at a point at its center. (This is not generally true for non-spherically-symmetrical bodies.)\n",
"The strength ... |
At the end of WWII in Europe, when Germany was being defeated in April, 1945, and the Allied forces were closing in from the east and the west, were there any incidents where the Russians and Americans/British accidentally fired on each other not realizing that they were fighting their ally? | Well, searching through the LINKS provided, this seems to be the best example provided so far:
> It was Nov. 7, 1944 when a flight of American P-38s on a routine mission over Kosovo noticed an inviting ground target: a column of enemy infantry and armour out in the open and rolling towards a nearby town. Within moments the Allied fighter bombers peeled off and streaked down towards the formation, guns blazing. The enemy troops dove for cover as the planes finished their first pass and came around for another run. As the attack continued and the casualties mounted, the ground troops radioed for help. A nearby wing of nine fighter interceptors heard the distress call and sped into the area to drive off the attacking American planes. The P-38s broke off the attack and formed up to meet the new threat. A fierce dogfight ensued with both sides losing aircraft. After five minutes, the opposing squadron leaders ordered their planes to withdraw and the brief skirmish was over. This seemingly unremarkable incident, one of hundreds of encounters that took place in the skies above Europe that year, does stand out though, even 70 years later. That’s because those ground troops the Americans attacked weren’t Germans at all – they were part of the Red Army. And it wasn’t Luftwaffe planes that flew to their rescue – it was Soviet Yak-3 fighters. Worse, the Americans weren’t even flying over German-controlled Kosovo at all. Due to a navigation error, the P-38s were actually 400 kms away near Nis, Serbia, an area that had already been liberated by the Russians. [1] The U.S. hastily apologized to their offended allies and the entire event was promptly swept under the rug — just another inconvenient case of friendly fire.
As the moderator said, it would be great if you could write out exactly what historical event answers the question. This helps everyone who is interested and saves them time from all having to go searching through the links for an answer.
I guess I'm satisfied with these links, but really when I was asking the question, in my mind I was picturing infantry troops exchanging gunfire, or a tank battle, or maybe an artillery duel. Are there any examples of that happening? | [
"Following the lull in fighting, known as the \"Phoney War\", Germany invaded western Europe in May 1940. Six weeks later, France, in the mean time attacked by Italy as well, surrendered to Germany, which then tried unsuccessfully to conquer Britain. On September 27, Germany, Italy, and Japan signed a mutual defens... |
How can I estimate the size of clouds I see in the sky? | I am not a meteorologist, but can offer some geometrical perspective.
If you know the altitude, you can get the rest. From the angular position above the horizon and the altitude, you can get the distance by right triangle trigonometry. Alternatively, from the distance and the angle above the horizon, you can get the height.
Once you know the distance, you can use the angular size (how many arc minutes or degrees across it is) to determine the absolute size.
Now if you have two observers, you can get the height from parallax. For simplicity, imagine you see the cloud overhead, while your friend who is a distance *d* from you on the ground sees the cloud at an angle *phi* above the horizon. Then you know the height *h* satisfies h = d tan(*phi*). If neither you nor your friend is directly below the cloud, you can still do this to find the distance to the cloud. And now that you have the distance, you can get the rest. | [
"Cloud top height can be estimated from the ground by triangulation. However, this is often inconvenient as this is practically feasible only for isolated clouds in full view of (and some horizontal distance away from) the observers. Ground-based radars can be used to derive this cloud property (see this paper for ... |
how do audio wires work? how does a unit send something through metal wires that comes out of a speaker as a song/voice/etc? | Ever shaken a large sheet of paper back and forth and listened to the wobbling sound it makes? It's from the air being pushed back and forth. In other words a very primitive speaker.
Next, take 2 magnets, in one position, the attract each other, in a different position they repel each other. Now what if we can turn one of those magnets on and off? Such as sending current through an bit of coiled wire, and making an electromagnet. Now we can make the magnets repel or attract with out having to turn the magnet around. Now we've got a very primitive voice coil.
If we attach this primitive voice coil to a diaphragm, we can make the voice coil move back and forth, which moves the diaphragm back and forth several hundred - thousand times a second. That movement of the diaphragm moves the air, which transmits those vibrations to our ear, which we hear as sound.
Put your fingers on your throat, and making a hummm sound, you'll feel those same vibrations. The more complex the range of vibrations, the more complex the sounds.
| [
"Speaker wire is used to make the electrical connection between loudspeakers and audio amplifiers. Modern speaker wire consists of two or more electrical conductors individually insulated by plastic (such as PVC, PE or Teflon) or, less commonly, rubber. The two wires are electrically identical, but are marked to id... |
What's the smallest object that can become a black hole(due to plank length)? | The limit is around the Planck mass. When approaching this limit from above quantum gravity effects become important. | [
"A small mass has an extremely small Schwarzschild radius. A mass similar to Mount Everest has a Schwarzschild radius much smaller than a nanometre. Its average density at that size would be so high that no known mechanism could form such extremely compact objects. Such black holes might possibly be formed in an ea... |
i really don't want to sound racist, but why do so many indian people smell? | If you cook a lot with spices (rather than store bought jars) then it tends to get in your clothes and hair. Also I find I tend to sweat a curry smell when I've been eating a lot. | [
"BULLET::::- gālí rén (咖喱人) - A much more common contemporary term used to refer to Indians, derived from the use of curry in Indian cuisine and the perception that Indians eat food to some Chinese find to have a strong smell, and which Indians eat with their hands, a practice that many Chinese find to be dirty and... |
How is an ICBM, used to carry warheads thousands of miles over a presumably high altitude, different than a rocket used to deliver objects into space? Specifically, why does weather affect a space launch window and not affect a potential ICBM launch? | Many ICBMs have been repurposed to launch payloads to space and many rocket designs are based on ICBMs.
The difference is simply the expected reliability. If you lose a satellite worth $1B that is bad, better wait a day with the launch. If you lose a few nuclear weapons when both countries launch hundreds against each other: Whatever, and waiting a day is not an option anyway. | [
"To counter air defenses en route to the target, remaining at a low altitude for as long as possible allows the bomber to avoid radar and visual tracking and the launch envelope of older missile systems designed to be fired at targets overflying the missile site. However, a level pass at the target at low altitude ... |
As one of the effects of MDMA on the human brain, what is the exact mechanism by which MDMA affects the (left) amygdala? | MDMA causes release of massive amounts (well, "massive" in a relative sense) of serotonin and dopamine. Activation of seritonergic neurons in the amygdala is linked to a decrease in anxiety...thus, this is suggested to be part of the mechanism by which MDMA could be useful for PTSD and severe anxiety disorders. MDMA also does a lot of other things with other neurotransmitters (oxytocin, noradrenaline, etc.), but those appear to be in other places the brain/body than the amygdala.
But, the massive neurotransmitter release caused by MDMA is capable of actually permanently destroying seritonergic neurons in this part of the brain, leading to all SORTS of bad things...hence, why so much more research into proper dosing would be required to make this a viable long-term treatment for...well...anything.
Anyone: please feel free to add. My neuropharmacology may be a bit rusty.
Sources: [1](_URL_1_), [2](_URL_0_), [3](_URL_2_) | [
"At high doses, MDMA induces a neuroimmune response which, through several mechanisms, increases the permeability of the blood-brain barrier, thereby making the brain more susceptible to environmental toxins and pathogens. In addition, MDMA has immunosuppressive effects in the peripheral nervous system and pro-infl... |
How is it that (kinetic) energy appears or disappears based on your frame of reference? | Kinetic energy is only conserved within one particular reference frame. | [
"This equation states that the kinetic energy (\"E\") is equal to the integral of the dot product of the velocity (v) of a body and the infinitesimal change of the body's momentum (p). It is assumed that the body starts with no kinetic energy when it is at rest (motionless).\n",
"Correspondingly the kinetic energ... |
Is there such a thing as a non-reflective liquid? | There are actually metamaterials that have [Negative Indices of Refraction](_URL_0_). They were only discovered recently, but are interesting nonetheless. These substances will not reflect any light, no matter what angle you look through them at. | [
"BULLET::::- Reflected Color - Uncoated glass reflects light uniformly and does not cause reflected light to be distorted (a white light source reflected in a non-coated glass pane will still appear white). However, anti-reflective coatings typically cause some wavelengths of light to be reflected more than others,... |
if grapes become raisins when dried, why does mango when dried, remain as dried mango. | Well with plums to prunes it’s even weirder!!
Grapes dry into raisins. When juiced we say grape juice! No such thing as raisin juice!
Plums dry into prunes. However, there is such a thing a prune juice! How does prune JUICE exist if it’s dry plums? How can you juice something that’s been dried?? | [
"Raisins are produced commercially by drying harvested grape berries. For a grape berry to dry, water inside the grape must be removed completely from the interior of the cells onto the surface of the grape where the water droplets can evaporate. However, this diffusion process is very difficult because the grape s... |
why do animals shed fur all their lives, but when you make a fur coat, it doesn't shed? | Because fur on an animal works like hair on a person - it grows and sheadding is a built in way to keep it clean and maintained. Along with grooming habits like licking.
A fur coats fur does not grow, as a fur coat is not alive. And the skin has been treated to retain the fur as much as possible. | [
"Their long, coarse fur also protects them from sun and rain. Their fur, unlike other mammals, flows from belly to top, not top to belly, allowing rainwater to slide off the fur while the animal is hanging upside down.\n",
"Conservation efforts must take into account the properties of both the fur and skin. The o... |
how do car doors freeze shut? | There's one main thing that causes this and it is the rubber gasket that lines your entire door.
Over time, that gasket gets moisture in it. Since it's a rubbery porous material, it holds onto it. When it starts to get cold, that moisture freezes and sticks to the door frame. The only reason it does this when you leave the car sitting is because normally any "freezing" (to the frame at least) is intercepted due to regular opening and closing of the door. | [
"A lockout system is armed when the driver turns the ignition key to the \"on\" position and carries out a specified action, usually flicking a hidden switch or depressing the brake pedal twice. It is activated when the vehicle drops below a certain speed or becomes stationary, and will cause all of the vehicles do... |
Why is the moon's density lower than Earth's density? | You're correct about the formation theory. By that time, many of the heavier elements had already settled to Earth's core, and the Moon was formed from outer layers of Earth and possibly the impacting body which were thrown into orbit by the impact. So the Moon's formational material was a less-dense sample of the Earth.
Also, more massive bodies will simply compress their cores more than less-massive bodies. | [
"The fact that the Moon is less dense than the Earth is advanced as support for it to be hollow. The moon's mean density is 3.3 g/cm whereas the Earth's is 5.5 g/cm. One explanation of this discrepancy is that the moon may have been formed by a giant impact which ejected some of the early Earth's upper crust into i... |
why are so many resolutions considered 2k? | Because '2K' is a marketing term with no formal definition. Basically what the people selling the screens are trying to say is that the resolution is better than 1080p. | [
"5K resolution refers to display formats with a horizontal resolution of around 5,000 pixels. The most common 5K resolution is 51202880, which has an aspect ratio of 16:9 with around 14.7 million pixels (just over seven times as many pixels as 1080p Full HD), with four times the linear resolution of 720p. This reso... |
why is it that the word allegedly is used even though there is video evidence that the act was in fact committed? | If there's a video of a person who looks almost exactly like, say, "Mike Jones" robbing a bank and then smashing a kitten, say, with a brick or something, and the news says, "Mike Jones smashed a kitten with a brick after robbing a bank," and it turns out to be that one person in a million who looks like Mike Jones, then the actual Mike Jones can sue the pants off the news folks for defamation of character.
If a sleazy editor digitally alters a video of some unknown person biting the head off a rabbit into a perfect dupe of Mike Jones biting the head off a rabbit, and sells it to a news company, and the news company is all, "Holy Crap! Look at this video of Mike Jones biting the head off a rabbit!" again, Mike can sue them enough to buy his yacht, pay off his student loans, and maybe get a nice condo in Aspen and a jet to go with it.
"Allegedly" saves the network from very costly lawsuits.
EDIT: Once, when I was on an Alaskan cruise, I ran into a guy on the ship who looked just like me. We were both incredibly freaked out.
| [
"Suppression of evidence is a term used in the United States legal system to describe the lawful or unlawful act of preventing evidence from being shown in a trial. This could happen for several reasons. For example, if a judge believes that the evidence in question was obtained illegally, the judge can rule that i... |
why remove the downvote/upvote counter? | > Why remove the downvote/upvote counter?
Because it's never been accurate in the first place. Their "fuzzing" algorithm adds fake votes to comments and submissions to prevent bot networks from being able to know if they're accurately able to game the voting system. | [
"An option of casting a downvote is another feature of the proposed method, which allows voters an even wider scope to express their preferences by letting them designate a candidate they do not want to see elected. It is important to note that the idea of a downvote is not a novel concept. It is important to note ... |
breast implants | Silicone is placed in the required area. Procedure is similiar to plastic surgery. It feels good when you touch it. | [
"A breast implant is a prosthesis used to change the size, shape, and contour of a person's breast. In reconstructive plastic surgery, breast implants can be placed to restore a natural looking breast mound for post–mastectomy breast reconstruction patients or to correct congenital defects and deformities of the ch... |
Is there a limit to how many times you can gravity assist a space craft with one planet before it stops increasing its velocity? | There's an upper limit to the amount of times you can use gravity assists to accelerate without having to burn a lot of fuel to get another one. If you hit the escape velocity out of the solar system, you'd have to slow down at some point to loop back and get another encounter with anything in that solar system. The amount of fuel you'd need to slow down to get another encounter could be better used to burn during the gravity assist that slingshots you into an escape trajectory to get a faster escape trajectory in the first place. | [
"Similarly, while the orbital speed of an outer planet is less than that of the Earth, a spacecraft leaving the Earth at the minimum speed needed to travel to some outer planet is slowed by the Sun's gravity to a speed far less than the orbital speed of that outer planet. Thus, there must be some way to accelerate ... |
Could a musket actually be tap-loaded effectively and regularly, or is that just a myth? | Yes, you can tap-load a musket for a couple of shots, IF, as was typical, the ball is a loose fit in the bore. The tricky thing is that as the bore fouls ( and black powder creates a good bit of fouling) the ball will be tighter and tighter, and the fouling could also accumulate a little heavier at the breech end- meaning, you might think the ball is still a loose fit, but it only drops halfway before it stops. Now, if you were calm and everything was quiet, you might be able to tell if the ball had gone all the way down, it might make a satisfying "klonk" when it hit the breech end. But this would not be possible all the time, especially in a battle.
If the ball doesn't go all the way down, upon firing the barrel may swell up at the point just behind the ball ( more common) or the gun might actually blow up. Either would put the gun out of action.
There's also the problem of a loose ball simply rolling back out of the barrel, if the gun isn't kept inclined, or upright. Or, if it rolls halfway out, the barrel could swell on firing.
The loading drill with wad and ramrod would ensure that the solider would continue to have an effective musket. | [
"Musketoons had a brass or iron barrel, and used a wheellock, flintlock or caplock mechanism firing mechanism, like the typical musket of the period. They were fired from the shoulder like the musket, but the shorter length (barrels were as short as a foot (30 cm) long) made them easier to handle for those in restr... |
broadband pricing tiers — business vs. home | One reason that business is more than home is because it usually comes with higher uptime guarantees, different (better) technical support and issue response times, and less restrictions (generally you're not supposed run a webserver on a home connection, although you can certainly do it from a technical standpoint)
In regards to the difference between 8x1 and 10x2 you're not just paying for increased download speed, you're also getting double the upload speed. If you're running a service at your office that people need to pull data from (you host your own webservice, or something similar) the increase upload speed can help. However I find it absurd that 10x2 would be 3.3 times as expensive as 8x1 for similar plans. I'm assuming the 10x2 includes something else thrown in there, either a higher tier of service, better SLA or similar. | [
"Middle-mile provision is a major issue in reducing the price of broadband Internet provision by non-incumbent operators. Internet bandwidth is relatively inexpensive to purchase in bulk at the major Internet peering points, and access to end-customer ports in the incumbent operator's local distribution plant (typi... |
Were there differences in the quality of metalworking between the Roman Empire and medieval Europe? | The quality of iron objects improved immensely after the collapse of the Roman iron industry.
Archaeometallurgists (people who study the metallurgy of archaeological artifacts) use a method called metallography to evaluate the quality and composition of metal artifacts. You cut a cross-section from an artifact, polish it, etch it with acid to reveal the crystalline structure of the material, and examine it under magnification. This shows things like whether the artifact was made from iron or steel, how it was heat treated, whether the starting material was a course or fine alloy, etc. It also lets us reconstruct the steps of the process by which the artifact was assembled.
A few hundred iron artifacts from Roman and early medieval Britain have been analyzed over the past four decades, so we have a good sense of how these artifacts' materials, manufacture, and quality improved over time. What we see is that Roman iron artifacts were almost always very poor quality. They rarely used steel or harder phosphoric alloys, were rarely heat treated or hardened, and were typically made from a very course material. These knives would have blunted quickly--you would have needed to constantly resharpen them as they wore dull.
In the fifth century, the quality starts to improve. Smiths still aren't consistently heat-treating iron blades, but they're more likely to add a harder material to the edge. These knives were still not great quality, but they were on average significantly better (hardness values increase from about 100HV to about 150HV, ie knives were 50% harder--which means they held their edges longer).
By the seventh century, more knife blades are being made using steel as well as iron, and many are being heat treated. These knives were often as hard as modern knife blades (400HV+), and some were clearly made by specialized smiths who produced very consistent products.
You can find a lot of this material summarized in [this book](_URL_1_), and there have been many more studies in the past 30 years that confirm these initial findings.
So what's going on?
The Romans made a *lot* of iron, so much that you can track the pollution from their smelting furnaces in ice core samples from Greenland. Quantity doesn't mean quality, though, and Roman iron tools were on the whole not especially well made. The Roman Empire was, after all, merely a very large and well-networked collection of typical iron age communities; their achievement was scale, not innovation.
When the Roman empire collapsed, [its wide trade networks collapsed and individual regions were left to fend for themselves](_URL_0_). That meant fewer luxury goods circulating across the Mediterranean, and less surplus available for exchange. That put some limits on people's lives--fine imported pottery, for example, disappeared from Britain because it couldn't get there from the distant North African workshops (which, slowly, fell into obscurity as their markets collapsed). But local blacksmiths still had access to plenty of iron. In fact, in many parts of the empire, the collapsing high-status economy meant that more iron was available than before, because [smiths could scavenge raw materials from abandoned buildings that fell into disrepair](_URL_2_) as the empire's elite moved east or dwindled into poverty. With careful processing, [that scavenged recycled iron could be manufactured into very fine quality tools](_URL_3_)--which seems to have been what blacksmiths began to do starting in the late fifth century.
There's an old stereotype that technological knowledge was forgotten in the West after the collapse of the Western Roman Empire. This is at best only a half truth. High-status / elite architecture was largely abandoned in parts of the west where people stopped building in stone, and writing and education became less common--if you were a wealthy Roman, you might feel like the world you knew was coming to an end (some, certainly, did because we have letters they wrote describing their anxiety). Many less glamorous technologies improved once the empire had fractured into smaller regional economies, however. The Roman Empire was a parasitic structure that extracted significant amounts of wealth from its provinces as taxation in coin and kind, and its subjects spent much of their lives toiling, in poverty, to produce the wealth needed to feed the state. [As the empire broke up, ordinary people's lives improved in parts of the empire like Britain](_URL_4_), peasants had more time to diversify the kinds of crops they grew and the crafts they produced, and this sparked innovations in mundane agricultural technologies like plows, field management, crop diversification, and the quality of iron tools. | [
"By the height of the Roman Empire, metals in use included: Gold, Silver, Copper, Tin, Lead, Zinc, Iron, Mercury, Arsenic, Antimony (Healy 1978). As in the Bronze Age, metals were used based on many physical properties: aesthetics, hardness, colour, taste/smell (for cooking wares), timbre (instruments), aversion to... |
To what extent is Ibn Rush (AKA Averroes) regarded as the "founding father of secular thought in Western Europe"? | "Secular thought" is a tough thing to quantify here. Lots of people tend to look at him as secular simply because he opposed the orthodox Ash'ari ideas of Imam al-Ghazali, but he was by no means secular in the modern European sense. His greatest work was "The Distinguished Jurists Primer" a comparison study of the four schools of Islamic law. Hardly secular. | [
"Ibn Rushd, often Latinized as Averroes, was a medieval Andalusian polymath. Being described as \"founding father of secular thought in Western Europe\", he was known by the nickname \"the Commentator\" for his precious commentaries on Aristotle's works. His main work was \"The Incoherence of the Incoherence\" in w... |
Why are we so dependent on bees to pollinate our crops? | Bees don't eat the pollen, they just spread it. That being said, bees are primary pollinators for a great many plants, and in some cases the exclusive pollinator. Some plants just plain aren't attractive to anything *but* a specific species, such as a certain bee. In cases of these exlusive pollinators, they is simply no simple alternative. Just need to hope *something* pops up befor the plant dies out. In the plants with multiple pollinators, there are other insects, birds, or mammals. But even in these cases, these might not be enough to sustain the population. The results of a species to mating or reproducing at a significantly rate could be catastrophic to that species. | [
"Some crops, especially when planted in a monoculture situation, require a very high level of pollinators to produce economically viable crops, especially if depending on the more generalized honeybee. This may be because of lack of attractiveness of the blossoms, or from trying to pollinate with an alternative whe... |
Why do Russian military aircraft have a teal interior paint scheme? | > easy on the eyes
That's part of the reason. It's meant to keep pilots calm in combat and allow for easier transitions when looking inside and outside. The VVS started using it in WW2 but it's been kept around with some interesting innovations; for example, Fulcrums and Flankers have instruments that glow under UV light rather than conventional night lighting, which is supposed to reduce eye strain when combined with the blue cockpit color. I'm not sure how scientifically grounded the VVS's ideas about this are, though. The calming effect might be total bullshit, so you'll need someone with a background in psychology to answer that (I'm just a plane nerd). | [
"Tasma – in Russian Cyrillic characters is a Russian GOST and ISO certified manufacturer of black and white photographic, x-ray, aerial, holographic, industrial radiographic testing, anti-fog, thermal, micrographic, and graphic arts films. It also manufactures adhesive tape, and demineralized water. Located in Kaza... |
cardinality, what is it, and how does it work? | "Cardinality" pretty much just means size. The cardinality of a set is its size.
Commonly, instead of formalizing the cardinality of a set as a particular thing, we formalize the idea of one set being bigger than another, or two sets being the same size. So if A and B are sets and |A| and |B| are their cardinalities, |A| < = |B| means that the cardinality of A is less than or equal to the cardinality of B. This happens when there's an [injection](_URL_2_) from A to B. But |A| and |B| by themselves don't really have meaning here.
This way of thinking about cardinality is usually good enough, but, another way of formalizing cardinality is with [cardinal numbers](_URL_0_), where we assign |A| to a particular object (a carinal number). This method of defining cardinality is basically the same as the first way, except we just pick certain sets to be the "standard" ones that we always compare against.
Blog post I wrote on cardinal numbers, if you care: _URL_1_ | [
"Cardinality is studied for its own sake as part of set theory. It is also a tool used in branches of mathematics including model theory, combinatorics, abstract algebra, and mathematical analysis. In category theory, the cardinal numbers form a skeleton of the category of sets.\n",
"In mathematics, the cardinali... |
How are Particle collisions imaged? | > do the detectors use Xrays?
No, all our particle detectors for particle physics are actually passive devices. They often get described in public lectures as being large digital cameras...and I think that is a reasonable (albeit simplified) way of looking at things.
So what a lot of these particle collisions you are looking at in your link are actually just the trajectories of particles that are produced in particle accelerator collisions (the colliding particles could have been, proton, electron, heavy ions, or a combination of any of the previous). The way we measure the trajectory varies from experiment to experiment. However, the basics are always the same. A particle leaving the collision point will radiate out and hit some of the "tracking" material (can be a gas, like xenon, or a solid, like silicon). This collision will liberate electrons from the struck material. If an electric field is being applied to this tracking medium, the electrons can be attracted to some specialized electronics that can register a current/voltage. If we have lots of these readouts placed all around the interaction point (nowadays we have *millions* of different readouts for trackers at the LHC), then we can tell which readouts were "hit" by the flying particle and reconstruct the path the particle must have taken (this is actually a fairly complex fitting procedure...I believe Shavera is a tracking expert, hopefully he'll come along...).
So really, when we are looking at these photos, we are looking at the digital reconstruction of a particle smacking into our electronics. And as such, there really is no "original" as you put it. We are not able to see these subatomic particles (we can't see an electron, but we can see the photons being scattered by it).
I hope that helped a bit! | [
"Each particle-target collision is called an \"event\". An elaborate data acquisition system records each event measured by the particle detectors, up to several thousand events per second on average. This data is then transferred to a \"farm\" of computing processors. Teams of physicists analyze the events, lookin... |
Help in understanding the geography of Greece at the time of the Peloponnesian war. | > Is Attica the name of the main body of land in southern Greece?
[Attica](_URL_3_) is the general area around Athens.
> Was the main body of the Pelopennes the northern landmass of Greece?
The [Peloponnesus](_URL_0_) is the big southern peninsula (Though it looks almost like an island on maps) where Sparta was.
> I've found reference to the Corinth canal; what is the name of the water passage that connected the Adriatic and Aegean seas?
I don't recall reading anything about a Corinthian Canal in Thucydides (Though it's been a while). [The canal there is a relatively recent thing.](_URL_2_)
Good luck with Thucydides. It can be a difficult text. If you are interested, the best version to read is [The Landmark Thucydides](_URL_1_) by Robert Strassler. There is a lot of good commentary, useful maps, and timelines. It's really helpful for deciphering what can be a very dense work. It's also not very expensive!
| [
"The Peloponnesian War was a radical turning point for the Greek world. Before 403 BC, the situation was more defined, with Athens and its allies (a zone of domination and stability, with a number of island cities benefiting from Athens' maritime protection), and other states outside this Athenian Empire. The sourc... |
how can stores sell things on sale while still making a profit? | There are two things to consider:
1. Stores have a larger markup on items than you might imagine. But they're not "ripping you off". They have to sell things at a high markup to be able to pay for the building, and pay their employees.
2. Many sale items are called "loss leaders". They sell these items to you at a loss in order to get you into the store, because they know that, on average, customers will buy enough other stuff to make up for the loss. | [
"In reality, Pottery Barn—a chain of upscale home furnishing stores in the United States—does not have a \"you break it, you bought it\" policy, but instead writes off broken merchandise as a loss, as do most large American retailers. Legal doctrine also holds that a retailer incurs the risk that merchandise will b... |
Where does the energy to keep Europa's ocean liquid come from? Conservation of energy question. | [I would explain it, but wikipedia does a good enough job](_URL_0_) | [
"The energy provided by tidal forces drives active geological processes within Europa's interior, just as they do to a far more obvious degree on its sister moon Io. Although Europa, like the Earth, may possess an internal energy source from radioactive decay, the energy generated by tidal flexing would be several ... |
I found this painting cleaning out my grandfather's house- anyone know who it is (probably German)? (X post from /r/AskHistory) _URL_0_ | It is [Józef Piłsudski](_URL_0_). | [
"The house was opened to the public as a museum in 1948. A major attraction of the museum is the portrait that the artist Elizabeth Shoumatoff was painting of him when he died, now known as the \"Unfinished Portrait\". It hangs near a finished portrait that Shoumatoff completed later from sketches and memory.\n",
... |
I recently found a knife handle from a US Army mess kit and I want to know a bit more about it. | A Model 1917. Most military surplus stores have them in bins for small change. Staple of campers and Boy Scouts everywhere. | [
"Ontario Knife Company is most well known as a supplier of military knives. Throughout the years they have supplied the U.S. military with products such as the M7 bayonet, the USAF Survival Knife, the M1942 Machete, the Navy MK3 MOD 0 diving/survival knife, the M9 bayonet, and most recently, the USMC OKC-3S Bayonet... |
Until Clinton's presidency in the 90s, California voted mainly Republican senators and governors and Texas voted mainly Democrat ones. During and since Clinton, California has voted mainly Democrat and Texas has voted Republican. What caused this drastic switch? | Concerning Texas and the South (can't speak for California). I'll attempt a brief summary of many events, some of them bloody. It was a drastic switch and a drastic time.
The Democratic party began to lose the south with the passage of the Civil Rights Act of 1964 and the Voting Rights Act of 1965. (50+ years ago) This was the beginning of the move to the Republicans.
The 1960's had experienced major race riots in several cities, people were killed, National Guard deployed in the streets and property burned to the ground. The Democratic party was divided over civil rights and opposition to the Vietnam War. Conservatives supported the Vietnam War and liberals wanted to withdraw.
Lyndon B. Johnson (LBJ) was president and wished to enacted major legislation he called "The Great Society". Conservatives opposed LBJ's legislation and as the Democratic party became more liberal conservatives moved to the Republican party. LBJ continued to press forward with the war contributing to a divided Democratic party. (LBJ and Vietnam too complex for this narrative.)
The 1968 Democratic National Convention in Chicago saw riots in the street and heated debates on the convention floor. Conservative Democratics saw this as an erosion of law and order and felt the Democratic party was weak on law and order.
1968 was a very tumultuous year. In April 1968, Martin Luther King Jr. was shot dead. In June 1968, Robert F. Kennedy (RFK) was shot dead. Kennedy was running for president and seeking the Democratic party nomination. Kennedy was viewed as a liberal and conservative Democrats opposed Kennedy. RFK was a brother of John Kennedy, president and was assassinated in Dallas, TX in 1963.
Richard M. Nixon, Republican, was elected president in 1968.
With the Voting Rights Act, the percentage of African Americans registered to vote in Mississippi increased from less than 10% to over 60%. Mississippi was the most dramatic state increase but all the southern states saw increased registration by African Americans. (I don't have numbers for Texas.) White southern conservative Democrats supported the Vietnam War and disliked the civil rights acts and they switched to Republican.
Lyndon B. Johnson (LBJ), president and a Democrat from Texas, was instrumental in turning Texas Republican. LBJ pushed civil rights laws thru Congress knowing the Democratic party lost the southern vote perhaps for a generation or longer.
In 1964 LBJ had been elected with 486 electoral votes. Barry Goldwater, Republican senator from Arizona, ran against LBJ and received 52 electoral votes. Voters liked LBJ.
In four years LBJ became so unpopular he didn't run for a second term and in a nationally televised speech famously said, "I shall not seek and I will not accept the nomination of my party as your President".
_URL_3_
_URL_2_
article/we-have-lost-the-south-for-a-generation-what-lyndon-johnson-said-or-would-have-said-if-only-he-had-said-it/
_URL_0_
_URL_1_ | [
"California was a Republican stronghold in presidential elections from 1952 until 1992. During this period, the Republicans won California in every election except the election of 1964. In these years, the GOP regularly nominated Californians as presidential candidates: Richard Nixon in 1960 and 1972, and Ronald Re... |
how can cats cover themselves in saliva daily and not stink? | Cat saliva contains a natural antiseptic which keeps their fur clean.
According to wiki "Nitrates that are naturally found in saliva break down into nitric oxide on contact with skin, which inhibit bacterial growth". | [
"Regularly bathing the cat may remove significant amounts of allergens from the fur. Furthermore, regularly brushing the cat will reduce the amount of loose fur (and its attached saliva) in the air. Feeding the cat a high quality diet with plenty of omega-3 fatty acids will help keep the coat healthy and minimize d... |
how culturally and technologically advanced were natives of australia compared to native american civilizations? | Well, that rather depends how you define "culturally advanced", doesn't it?
But by the usual metrics of technological advancement, mesolithic. | [
"The indigenous Australians, far from being a primitive people, have a highly sophisticated society and worldview which, in Turner's view, is in many ways more advanced than those of modern Western civilization. According to Turner, the Aborigines have developed several social mechanisms for ensuring social and env... |
why aren't you supposed to pour boiling water on honey? | If you believe that honey has healing properties, boiling water supposedly breaks down the enzymes or whatever responsible for those attributes. Like a lot of "natural medicine", it's not really based on any science.
If you just like something sweet in your tea, it doesn't make a lick of difference. | [
"The reason for making syrup with the honey is that otherwise it might be too thick to mix well with other ingredients, especially in an ice-filled cocktail shaker (as opposed to, say, a hot tea). An advantage of honey over sugar, for making cocktails, is that it can impart floral notes and also pair well with spir... |
How reliable was pilot kill counts during WW2? What kept pilots from inflating their scores for personal gain, or countries from doing the same for propaganda purposes? | In WWII, fighter pilot kill claims were generally exaggerated ~~by about a factor or 5 to 10~~(Edit: to a degree ranging from very substantial to very extreme), when compared against enemy loss numbers in records available after the war. This is true for all countries participating in the war. Even with gun camera footage, a group of pilots tended to double, triple and quadruple count planes that did go down. Plus many planes that were shot at and hit did not suffer serious damage and recovered after diving out of the combat area.
Most countries had fairly strict rules designed to prevent overclaiming. However these rules were frequently flouted and basically ineffective at combatting the problem. WWII Pilots under the pressure of combat were either unwilling or unable to prioritize getting the counts right for intelligence officers in charge of tracking enemy losses. The Air staff officers were aware of overclaiming as a problem, and discounted claims to some degree, however they had little information to go on. Sometimes the exaggerated claims were believed by the staff officers and they made incorrect decisions as a result. Undiscounted claims were sometimes used as propaganda, but the motivation for overclaiming was not primarily propaganda, it was just a property of combat conditions in air units.
Edit: This post got enough attention that I'm feeling guilty about the sourcing of the assertion in the first sentence. I'm going to make this much more vague until I can put a more substantial source behind the general size of the overclaiming problem. | [
"The \"Regia Aeronautica\" tended not to keep statistics on the individual level, instead reporting kills for a certain unit, attributed to their unit commander. However, pilots were able to keep personal log books, so the few that survived through World War II give individual statistics. Here is a list of the aces... |
why do cats sometimes kill smaller animals for no reason? | Think of the cat as a wild hunting machine that just so happens has been domesticated over hundreds, thousands of years, by man to be very good at doing one thing (that humans expected of it): kill things that eat our grain. If it is a small rodent, cat's got it. Bird? cat's got it. This behaviour is taught to kittens by the mother at an early stage: "get the small things that scurry.". Its just the way cats are.
Their eyesight is specialized towards tracking prey on a lateral axis (left-right; rodents don't "jump"), can see in low light (where rodents like to hang out.) have whiskers that tell the cat "nope, can't fit in there" (where rodents hang out).
My cat is an idiot. I love him, but he's dumb as toast. But even this idiot can kill the occaisional mouse. After its dead he kinda bats it around expecting it to get up and run away again (leaving dead mouse all over my linoleum), but his instinct kicked in, said "I must kill this thing that my supernatural hearing allowed me to detect in my can-opener's kitchen; thank god the can opener did not have my claws removed". | [
"Cats hunt small prey, primarily birds and rodents, and are often used as a form of pest control. Domestic cats are a major predator of wildlife in the United States, killing an estimated 1.4 to 3.7 billion birds and 6.9 to 20.7 billion mammals annually. The bulk of predation in the United States is done by 80 mill... |
What kind of advancements are being made in weather forecasting? | It's probably more of the opposite, NOAA funding cuts means they won't be able to replace satellites and can barely maintain current ones. | [
"The Travelers Weather Research Center (1954-1961) was the world's first privately-owned research institute for the scientific study of weather. It pioneered the use of statistical methods, mathematical models, and computers to improve weather forecasting techniques, and was the first to state weather predictions i... |
Camel cataphracts and similar cavalry units-- the real deal or a cute little anachronism? | To make a long story short-
Armored cavalry with armored horses are a VERY old concept, and were incredibly effective.
The byzantines, at various times in their history, were infamous for deploying (comparatively) large groups of them, and using them rather skillfully in concert with pike and shot+lighter cavalry+ armored horse archers.
The french ordnance companies actually started out requiring men to take the field on armored horses as well, and were rather effective.
Here
_URL_0_
Wikipedia isn't the best source, but the fever I have means I'm not goign to be able to figure out which tactical manuals to link you too.
To learn more about the byzantine army, i'd recommend reading The Grand Strategy of the Byzantine Empire.
It is incredibly comprehensive, easy to read, and worthwhile. Uses a good number of primary sources, too.
As for the french:
_URL_1_
If I get over this sickness in a reasonable timeframe, i'll break out my books and google-fu to find you some decent sources and actual citations.
Can't talk about armored camels, i've never heard of it outside of video games. | [
"Camel cavalry, or camelry (, ), is a generic designation for armed forces using camels as a means of transportation. Sometimes warriors or soldiers of this type also fought from camel-back with spears, bows or rifles.\n",
"Camel cavalry were a common element in desert warfare throughout history in the Middle Eas... |
cancer. | Cancer is essentially rampant cell growth. The cells in your body are constantly replicating in order to keep you alive and kicking.
How do they know when to start and stop this replication, though? There are a few genes (proto-oncogenes and tumor suppressor genes) that pretty much function as a traffic light for cell division (mitosis). Proto-oncogenes are the green light, while tumor suppressor genes are the red light.
Carcinogens (which I'm sure you've heard of) are things that can cause a mutation in the DNA of either one of these genes, meaning that they don't function properly. I'm not actually sure if only one, or both kinds of genes need to be malfunctioning for cancer to occur, someone else will have to clear that up for you.
When the genes are mutated, the result is that the cells undergoing division are told "Go go go!" but they aren't being told to stop, as they usually would. They just keep dividing, forming a mass known as a tumor. Benign tumors, which don't do anything but hang out and divide aren't technically cancers, though they form in a similar fashion and can cause some pretty serious health problems in the long run if untreated. The real cancerous bad guys are malignant tumors, which can send little parts of themselves into your bloodstream (or lymphatic system) and establish another colony, so to speak, somewhere else in your body. That's the bad part. You may have heard it called metastasis.
Eventually the cancerous cells inhibit organ function by either hogging resources or blocking their pipes. The organs then shut down, which is why cancer kills people.
TL;DR: You've got 1000 people living in a town where, for some reason, the human reproductive cycle takes a mere 24 hours. Two people decide they want to take over because the sun messed with their DNA and made them crazy. They churn out children who proliferate and populate the town. It got really serious when a couple of them hitchhiked a few suburbs over. The community can no longer support this new large family and the whole town dies from starvation. | [
"Cancer is a group of diseases involving abnormal cell growth with the potential to invade or spread to other parts of the body. These contrast with benign tumors, which do not spread. Possible signs and symptoms include a lump, abnormal bleeding, prolonged cough, unexplained weight loss, and a change in bowel move... |
What would the effects on the human body be from going from -70F to 110F weather very quickly, as it is a difference in 140F? | Well, I happen to know some people who've gone from +200F to -100F ass naked, and they survived to tell the [awesome] story. It's called joining the "300 club", and is a common ritual for winterovers at the Amunsen-Scott South Pole station (and maybe other places, I don't know).
When the temp outside gets to -100F (which only happens during the austral winter, so around this time of year), you go into the sauna (which you can get above 200F), then run naked outside around the South Pole and back into the station.
I've gone from +200 F to -40F or so (in a swimsuit) and I survived. Granted, this is at ~9000 ft elevation and with practically no water vapor in the air, so it takes awhile for the cold to draw the heat away from you.
Water vapor from condensation/sweat from the sauna freezes on your body hair and makes you look like a yeti, which is kind of cool. It would probably get pretty bad if you tried to stay out much longer than 5-10 minutes (frost bite, hypothermia, etc.), but it's largely a matter of making yourself deal with the cold for a few minutes at least.
I've heard stories of people fainting after heading out from the sauna in the cold, but never seen it myself. | [
"BULLET::::- The wind chill factor measures the effect of wind speed on cooling of the human body below 10 °C (50 °F). As airflow increases over the skin, more heat will be removed. Standard models and conditions are used.\n",
"The U.S. National Weather Service defines \"extreme cold\" as with winds less than . I... |
how does "making yourself heavy" make you heavier to carry? | When you "make yourself heavy", you go limp, meaning that whoever wants to carry you must support and maneuver your entire body weight. This makes you feel a lot heavier than if you were supporting yourself in small part using your legs or arms. Your instinct is to support your weight with your legs a bit where possible, so unless you are concentrating on staying limp, you're not as "heavy" As you could be. | [
"Weight lifting can effectively demonstrate the effects of post-activation potentiation. For example, if a person lifts a light weight, and then lifts a heavy weight, before lifting the light weight again, the light weight will be relatively easier to lift and feel lighter the second time it has been lifted. Becaus... |
why do countrys seprate into states? | The US didn't separate into states. The states chose to unite (but still retain their existence as states). | [
"If the states do not unify into a single nation there will be a perpetual cycle of conflict between neighboring states. Their alliances or dis-unions create circumstances similar to European nations, where the cycle of aggression between neighboring nations creates the need for domestic armies and fortifications. ... |
During the French Revolution, many French officers had fled abroad, and the ones who stayed feared their own troops. The new Revolutionary Army was comprised of poorly trained conscripts against multiple, better trained armeis. So how did France mange to win the War of the First Coalition? | I want to concentrate on the period 1792-1794, which is the initial post-revolutionary period, with context surrounding these years.
After the War of the Austrian Succession in 1750 France founded the Ecole Millitare, which in 1777 became the École des Cadets-gentilshommes. Its intention was to train not just high nobility to become officers, but also the sons of those wealthy and connected enough to be able to secure a place. While it was not meritocratic as modern West Point or Sandhurst, institutionally it was designed to foster learning, tactical knowledge, and encourage freedom of thought within the cadets. When Napoleon attended in 1784 he was assigned as an artillery cadet, which was one of the most prestigious positions due to the maths and tactical knowledge required. The French of the pre-revolutionary period understood the need to innovate militarily, and when the counter-revolutionary wars broke out there remained enough of an officer core that this innovative spirit remained. While it is also true that some of the remaining officers feared their own troops, the vast majority of the officers who remained were competent and usually well regarded by their men.
In respect of the War of the First Collation, the French had four major advantages over their enemies:
1) They were fighting for their own liberty on their own boarders with more or less secure supply lines and logistics (though Napoleon was always complaining about extortion from suppliers). This meant that while they fought on French or near-French soil they were usually adequately supplied with munitions, boots, horses, fodder, and other essential supplies. This was crucial in keeping the army together during the winter months, and allowed the French generals to ensure that when the campaigning season began they could fight any advance their opponents made.
2) France was a single nation fighting a coalition of disparate political ideologies. On the one hand Britain was a maritime merchant parliamentary democracy that feared French impingement on trade and an explosion of workers demanding rights. On the other, you had the autocratic monarchies of Prussia, Sardinia, and the Holy Roman Empire in the form of Austria. The coalition was disjointed, and while the coalition did enjoy success along the Rhine, because the lack of clear communication among the allies no one decisive blow was ever struck against the French because there was no effective co-ordination of military manoeuvres. For instance, at the end of the 1792 campaigning season Prussia withdrew back into her own boarders due to the economic pressures of the war, and none of her allies were able to press home the advantages she gained during her initial invasion.
3) Conscription. While it is true that in 1792 there was mass desertion of French troops, in 1793 the French were able to conscript 300,000 men via the levee en masse, which was more than the allies could place into the field. In 1793 the French had to fight on four fronts extending out from their boarders: The Netherlands, the Rhinelands, northern Italy, and the Spanish boarder. While there were rebellions in the Vende (southern France) which were serious in nature, due to the conscripted army the French were able to hold their own, and by the end of 1793 had pushed back the coalition.
4) Bear in mind that while Napoleon was the most high profile general to come out of France during this period, it took him until 1794 to gain command of an army. In the initial 18 months of the revolution men like Lazare Carnot (who introduced modern waging of war with mass armies and strategic planning),
François Christophe de Kellermann (who commanded on the Rhine), Paul Barras (Commissioner to the French Army), and Jean-Baptiste Jourdan (who commanded the army in the north) all had a hand ensuring that the revolutionary army was well led and well organised. The aristocratic and counter-revolutionary classes may have fled, but many capable men remained in positions of authority during 1792/3 to ensure that while the reign of terror decimated the revolutionary ideals, France herself was kept safe from the first coalition.
So, in answer to your question: France managed to win the War of the First Coalition through a combination of the right men in the right places (such as Baras and Kellerman), a short logistics train, patriotic fervor to keep the coalition from succeeding, a highly trained and questioning officer corps, and dysfunction among the members of the coalition.
It should be added that in 1812/13 all of these factors would come back to haunt Napoleon on his Russian campaign, and the subsequent campaign that finally defeated him. Long supply trains, dysfunctional coalitions, and lack of patriotic cause led to his downfall.
Sources:
Napoleon the Great by Andrew Roberts
The Romanovs: 1613-1918 by Simon Sebag Montefiore
Alan Forrest, Soldiers of the French Revolution
TCW Blanning, The French Revolutionary Wars | [
"From 1793 to 1795, French successes varied. By 1794, the armies of the French Republic were in a state of disruption. The most radical of the revolutionaries purged the military of all men conceivably loyal to the \"Ancien Régime\". The \"levée en masse\" created a new army with thousands of illiterate, untrained ... |
British officers in WW1 | > the officers and higher ranks were all taken from public schools rather than due to experience
This is only partially true; yes, a great majority would have attended public school, considering that it took money and education to be an officer. As a result, most would have been upper and middle class, but this was little different from other European armies. Moreover, officer and general selection pre-WWI was based on confidential reports, filed annually for all officers, examining their background, manner, peacetime service and whatever combat experience they may posses. The process was meant to seek out the best individuals, those well suited for the role of command. When the BEF went into battle in 1914, it did so with a highly professional, and for the most part capable, array of Senior and Junior Command and Staff officers.
> which is why so many stupid decisions were made
The issue that the BEF was confronted with in 1915 was that the BEF, a professional volunteer force 120 000 strong, was all but gone. The ranks were virtually purged of Regulars, as a result of the heavy losses experienced in the high intensity campaigns of 1914. 10 British Generals were casualties in 1914, and losses among staff officers were so prohibitive that they were expressly forbidden from visiting the Front (most ignored this). The result was that in 1915, officers had to be combed out of staffs at home and across the Empire, brought out of retirement or called up from the ranks, to fill positions in a force that was the size of an army in 1914, then contained 3 armies by the end of 1915, then 5 by the end of 1916! The BEF was, in a sense, 'de-skilled', and it would take time for it to be 're-skilled'. Being the junior coalition member on the Western Front meant that they did not always have the opportunity to 'pick their battles'.
The result was that yes, many generals were admittedly poor, even god awful. Some like Thomas Snow acknowledged that they were not quite suited to the task at hand in their diaries; others like General Pilcher during the Somme were ferreted out of the ranks.
> why was this this not recognised and the officers replaced with experienced soldiers regardless of class as the war went on
By the end of the Somme battle, the officers of the BEF had been well put through their paces; by 1917, the performance of the organization was vastly improving. At the lower level, officers at battalion and brigade level actually became younger, and by 1918 Anthony Eden was the youngest Brigade Major in the BEF, at 19!
By 1918, the BEF had been well 'run in'. Command in the Hundred Days Offensives began to delegate to the division level, as exemplified by the 46th North Midland Division at the Riqueval Bridge (St. Quentin Canal), which pierced the Hindenburg Line in mere hours.
By 1918, the BEF was arguably the most formidable fighting force ever put forth by Britain. | [
"Field Marshal Sir William Robert Robertson, 1st Baronet, (29 January 1860 – 12 February 1933) was a British Army officer who served as Chief of the Imperial General Staff (CIGS) – the professional head of the British Army – from 1916 to 1918 during the First World War. As CIGS he was committed to a Western Front s... |
Can someone briefly explain the Lorenz Attractor? | The Lorenz Attractor is a set of differential equations which was originally formulated to describe a certain physical situation in phase space. That is, the coordinates of each point of the "line" describe the state of the system, and the line its evolution over time.
It's an attractor because with those equations anywhere you start within a certain area, the state will always say bounded within a certain area. The lines will always loop around those two butterfly loops.
If you follow the evolution of the thing, the line loops around the two halves back and forth in an irregular fashion one or many loops around the left and then switch to the right, but never ever repeating itself. It is "strange" or "chaotic" because if you move any point along the line an arbitrarily small amount, it will result in completely different patterns and paths around the loop no matter how small the change you make. | [
"The Lorenz system is a system of ordinary differential equations first studied by Edward Lorenz. It is notable for having chaotic solutions for certain parameter values and initial conditions. In particular, the Lorenz attractor is a set of chaotic solutions of the Lorenz system. In popular media the 'butterfly ef... |
why do the facebook app and mobile site require you to download the messenger app, when opening a desktop version on my phone lets me use the messaging system just fine? | I don't know but I refused to download FB messanger because I didn't like all the access it was requesting. If you use Chrome - just check "Request desktop site" in the settings and you can access your messages through FB in the browser. | [
"Complementing regular conversations, Messenger lets users make one-to-one and group voice and video calls. Its Android app has integrated support for SMS and \"Chat Heads\", which are round profile photo icons appearing on-screen regardless of what app is open, while both apps support multiple accounts, conversati... |
In WW2, why were troops allowed to paint on their planes etc? It seems like they would give away their position rather than modern camouflage patterns. | Painting of aircraft and the levity allowed for individual markings depended on the time, place, air service doctrine and conditions.
For example Royal Air Force and Germany-based Luftwaffe aircraft tended to be painted in the standard schemes proscribed by the high command. Individual markings such as crests, cartoons or victory markings were either discreet, or were a privilege of success or seniority. The VVS (Soviet Air Force) allowed, indeed often encouraged, patriot slogans but again individual markings were relatively rare.
The USAAF took a somewhat more relaxed attitude, especially for its forces based in England (and therefore at some distance from the 'top brass'). Their commanders were often young officers who led with flying skill and charisma, and individual markings proliferated. A key reason for this was that for most of its time, the 8th and 9th Air Forces in England were dominant and aggressive: they had little reason to hide and this is why we see the late-war fleets of B-17s and B-24s flying in natural metal finish. The Allies by this time had such a huge advantage in numbers, training, and equipment that they could *dare* the Luftwaffe to come at them.
Proving the rule, as the Luftwaffe came to be hunted on the ground and in the air in 1944, as the only viable combat tactic was to hit and run, their aircraft became darker, more drab, and with few individual markings. Interestingly, this is pretty much the reverse of the situation in 1940 when Royal Air Force aircraft, fighters and bombers, were painted brown and green for camouflage on the ground, while the Luftwaffe's Messerschmitts had sky blue sides and bellies, for better camouflage in the air.
As the Royal Air Force moved into an offensive posture in 1941-2, it's fighter scheme became grey and green, for better camouflage over water and in clouds. Other schemes were developed for night bombers, coastal patrol and attack aircraft, night fighters (which, it was proved, needed a different scheme to night bombers!), and desert-based aircraft. The intense fighting over the Mediterranean island of Malta saw local colour schemes applied emphasising blue to blend in with the turquoise waters, a rare case of prolific use of non-standard paint in the RAF. A similar situation applied to parts of the Eastern Front, where the Luftwaffe's *Jagdgeschwader 54* used captured paint to camouflage its aircraft in summer, 1942.
A significant minority of RAF night bombers received individual markings. My father's Lancaster had two distinct nose art pieces at different times, one in chalk and one in paint. The original was overpainted when the aircraft was given a major service.
The US Navy had a very different attitude to the Army, and individual markings were very rare and very small. A fighter squadron that applied a 'cat's teeth' marking to its F6Fs was ordered to overpaint the markings. This was an example of service culture rather than tactical considerations.
A final issue is the schemes needed to be simple: early in the war the USAAF experimented with some very elaborate colour schemes intended to deceive an attacker as to his 'victim's' distance, direction and attitude, like naval 'dazzle' schemes. While they worked very well, it was found not worth the effort to paint on the intricate patterns.
Some people reading this will be able to cite examples that seemingly prove how planes could be painted any which way, but it is worth remembering that unusual schemes tended to attract photographers!
*Fighter Colours* Michael Bowyer.
*Bomber Colours* Michael Bowyer.
*Soviet Air Force Fighter Colours, 1941-45* Erik Pilawskii
| [
"While camouflage tricks are in principle limitless, both cost and practical considerations limit the choice of methods and the time and effort devoted to camouflage. Paint and uniforms must also protect vehicles and soldiers from the elements. Units need to move, fire their weapons and perform other tasks to keep ... |
What is the difference between vapor and gas? | All condensed phases of matter have finite "vapour pressures" meaning that they lose mass by evaporation unless/until a dynamic equilibrium with the gas phase is reached. The vapour, then, is the gaseous form of the material (from evaporation) at a temperature below its boiling point. | [
"\"Vapor\" refers to a gas phase at a temperature where the same substance can also exist in the liquid or solid state, below the critical temperature of the substance. (For example, water has a critical temperature of 374 °C (647 K), which is the highest temperature at which liquid water can exist.) If the vapor i... |
What qualifies a certain aquatic species to be called a shark? | [Six reasons.](_URL_0_) Second Google search result. Very clearly-written explanation, I like this site. | [
"The bramble shark (\"Echinorhinus brucus\") is one of the two species of sharks in the family Echinorhinidae. Aside from the eastern Pacific Ocean, it is found in tropical and temperate waters worldwide. This rarely encountered shark swims close to the bottom of the seafloor, typically at depths of , though it may... |
Could someone recommend me articles/books on the subject of the development of hereditary feudal system? | You'd probably do well to check out [*Fiefs and Vassals* by Susan Reynolds](_URL_1_). It's pretty much essential reading if you want to know the other side of the debate with Bloch's view that's been rumbling on since [Elizabeth Brown's article *The Tyranny of a Construct*](_URL_0_). | [
"With feudal barons and feudal counts one saw the introduction of a neo-feudal structure in Norway. These modern fiefs were ruled with conditioned independence by noble families, and they were hereditable. Feudal lords were equipped with extensive rights and duties. On the other hand, a fief was formally a \"domini... |
how did worms get inside a mango seed if it didn't make any holes on the outside. | They burrow inside before the seed is fully matured.
> The newly hatched larva is about 1 mm long and burrows through the pulp and into the seed where it will remain until it becomes an adult. Minimum time from hatching to seed penetration is one day. There are at least five larval instars in Hawaii. Larvae can penetrate the seed coat easier on younger fruit of all varieties, and apparently find entry impossible on mature seed of some varieties (e.g., Itamaraca). As the fruits mature, the tunnels are eliminated and it is not possible to distinguish between infested and non-infested seeds, unless they are cut open (Pertanian 2004).
Assuming we're talking about mango seed weevil larvae. | [
"The caterpillar larvae eat all sorts of dry leaves, in which they build silken tunnels. They have also been recorded on living plants of the looking-glass mangrove (\"Heritiera littoralis\"), though the significance of this is unknown.\n",
"Once the virus reaches the seed, it is believed that it is harbored in t... |
Why was George Washington elected as "President" and not, for example, as "Chancellor", "Leader", or "Director"? Why was "President" specifically used? | [This answer](_URL_0_) by /u/bigslothonmyface explains why "President" was chosen over a more elevated title. They don't give a reason why "President" specifically was chosen though. | [
"George Washington impacted the role of the presidency from his inauguration to his retirement. From the beginning, Washington did not want to resemble a king or be referred to as one. He preferred the title \"Mr. President,\" which is how presidents are still addressed to this day. Washington also shaped the inaug... |
why do employers give new employees higher salaries, rather than rewarding loyalty and giving the better salary to employees already there? | The question you have to ask yourself is why would they.
Your coworker still works there. There is no incentive for your bosses to pay them any better than they currently do. Sure loyalty is virtuous and should be rewarded, but companies dont care about virtue. They care about making money, and every dollar that is given to a worker could go to profits for the owner or pay newer workers who might not work for as cheap. In this sense the only reason to give a worker a raise is to prevent them from quitting or unionizing. | [
"Some employees are paid more for they are presenting that they are worth a greater amount since they can perform more than one job function and thus makes a higher incentive for more employees to be able to perform better in the workplace. \n",
"The reason that employees are often paid according to hours of work... |
why is the vision of spiders depicted as them seeing 8 of the same image as opposed to those 8 eyes merging the images together like human eyes? | Because that's literally how they work! It's called a compound eye, and it is comprised of many similarly shaped pieces that "see" independently from the others.
As a result, their vision looks like many repeats of the same image. It's actually incredibly useful because they see every tiny movement many, many times and so they can be quick to react. This is what makes it sometimes difficult to swat flies and such. | [
"The spider has four eyes (2 small ones on the sides, 2 large ones in the middle), and is only the second known species to cephalopods to have such vision. The species are gray coloured with brown dots.\n",
"Spiders have primarily four pairs of eyes on the top-front area of the cephalothorax, arranged in patterns... |
what is that we see as happiness/love/desire/sadness/depression in someone else’s eyes? has then something physically changed in person’s eyeballs or how are those feelings manifested that make us to perceive them so effortlessly? | It's the combination of eyelids, cheeks, and eyebrows. Those three areas of the face are all very close together, and very slight differences in angle and tension can communicate a wealth of information about what the person is thinking/feeling. Cycle through a few emotions and feel how your eyelids shift, how your cheeks lift or lower very slightly, how the angle of your eyebrows change very slightly. We learn to read those slight shifts throughout our lives, and when people are trying to control their expression they tend to focus mostly on what their mouth is doing, rather than their eyes. | [
"Neuroscience and brain imaging have shown increasing potential for helping science understand happiness and sadness. Though it may be impossible to achieve any comprehensive objective measure of happiness, some physiological correlates to happiness can be measured. Stefan Klein, in his book \"The Science of Happin... |
what would landing on a flying aircraft carrier be like from a physics standpoint? | Pretty much. Seeing as how modern aircraft carriers already move in 3 dimensions (bobbing up and down on waves and such.) The physics of actually landing would be pretty much the same.
The only likely problem would be trying to land in the dirty air created by whatever the carrier was using to stay up. Like in the Avengers movies, those great big turbines would be causing huge crosswinds on the deck, making landing a real bitch. | [
"In the Royal Navy, \"landing on\" is usually achieved by first lining up on the port quarter parallel to the ship's heading, then once the deck motion is deemed to be acceptable the pilot sidesteps the aircraft laterally using a white painted line (the bum line) as a reference.\n",
"Other aeronautical investigat... |
why is it that when you hit a dimming/dying flashlight it becomes brighter and lasts for a little longer? | I'm sure it has something to do with the battery connection.
On a lot of remote powered things, remote controls are a great example, if you take the batteries out and put them back in they work a little longer. Works if you just twirl the batteries.
| [
"While it might seem astonishing that so many longest-lasting light bulbs have been so infrequently turned off, this is the precise reason for their longevity. Most of the wear and tear that leads to burnouts in incandescent light bulbs is caused by turning them on and off, not by burning them. Each time the bulb i... |
why was there all this question about whether or not russia sent troops to ukraine in this day and age? is it really not that black and white when they claim thousands of troops and tanks? | Russia did not send their regular army in, and they didn't involve their air force or other branches of their regular army.
What they did do was allow volunteers from all over Russia and Europe (even some from western countries like France) to pass through their border with Ukraine and join the rebels. Many of these volunteers were indeed people from the Russian military.
So were there Russian troops in Ukraine? Yes. Did the Russian army formally invade Ukraine? No. Hopefully you can see how both of these are true. | [
"Initially, it was stated that the arrival of the Red troops in Ukraine was due only to the need for the advancement of Soviet troops on the Ukrainian railroad that were heading against the rebellious Russian Whites under Alexey Kaledin,which had occupied Rostov-on-Don on 15 December 15. In December 1917 the Lenini... |
why is the x86 architecture the only real force in the home computer market? | To find the real reason, we need to go back to the early 1980s.
IBM wanted to make a home computer. They had a choice of operating systems, and eventually decided to go with Microsoft (that's a story by itself, but we'll stick with the relevant stuff for now).
During the negotiations, though, Microsoft won a key concession. IBM used Microsoft's operating system, called PC DOS, on their computers. But they won the right to also supply their own version of the software, called MS DOS. This meant that, unlike every other computer manufacturer, IBM were shipping a computer where they didn't own the sole rights to the operating system.
Aside from the operating system, most of the other components of the IBM PC were available off the shelf. The only exception was the BIOS, but this turned out to be relatively easy to reverse-engineer, find out how it worked, and build something similar enough to be compatible.
And so the "IBM PC Compatible" computer was born - a computer which was not made by IBM, but which would run all the same software as IBM computers. This resulted in a huge surge of software for IBM PC Compatible computers, which resulted in more of those computers being sold, and so more software was written, etc - it developed into a self-sustaining growth.
And to get back to your original question, those IBM computers used Intel chips. And so IBM PC Compatible computers also used Intel chips. And almost every PC ever sold since then has been based on the same technology, or evolutions of the same technology. | [
"Modern x86 is relatively uncommon in embedded systems, however, and small low power applications (using tiny batteries) as well as low-cost microprocessor markets, such as home appliances and toys, lack any significant x86 presence. Simple 8-bit and 16-bit based architectures are common here, although the x86-comp... |
How much did America REALLY help in World War I | America's contribution was pretty much vital in terms of the war finishing in 1918. From the point of view of the Western Allies, things were actually looking quite bleak in 1917. For one, the French Army (who had shouldered most of the burden on the Western Front) was nearing breaking point (something that resulted in mutinies amongst the troops) and the British offensive around Passchendaele didn't appear to be getting off to the best of the starts. However, the real strategic problem was that Germany made peace with Russia following the revolution and this freed up enormous amounts of manpower that could then be used to shore up the Western Front. Thankfully for the Allies, this development coincided with America's entry to the war so that most of Germany's strategic advantage was neutralised by the flood of American troops arriving in Europe. Had they not, it's conceivable that the fighting on the Western Front could have carried on grinding away inconclusively for years to come. | [
"The U.S. made its major contributions in terms of supplies, raw material, and money, starting in 1917. American soldiers under General of the Armies John Pershing, Commander-in-Chief of the American Expeditionary Force (AEF), arrived at the rate of 10,000 men a day on the Western Front in the summer of 1918. Durin... |
how do banks hold electronic money? | All banks must have accounts with the Central Bank (at least for US) but it isn't for the reasons you mention. Banks can simply debit and credit each other electronically without need for Central Banks to keep a record since each Bank will definitely keep a record of it (it is their core business!)
Banks must have an account with the Central Bank because they are required by law to maintain a reserve ratio the simplest explanation is that for every dollar they loan out, they must keep a certain fraction of the amount at the Central Bank. | [
"Commercial or retail banks use what is known as core banking software which record and manage the transactions made by the banks' customers to their accounts. For example, it allows a customer to go to any branch of the bank and do its banking from there. In essence, it frees the customer from their home branch an... |
Why is it believed black holes preserve mass, charge and angular momentum, but not baryon number, weak isospin and lepton number? | Basically nobody has a fully quantum mechanically sound theory that relates to black holes, so people don't know whether they expect these things to be conserved or not.
I would say these quantities probably are conserved but don't affect the properties of a black hole. To an outside observer matter never even reaches the singularity of a black hole, or even cross the event horizon if the black hole is not growing. As such there is no time (to an outside observer) for any weird physics to break conservation of these quantities.
The particles don't actually need to enter the event horizon to contribute to the black holes mass via the holographic principle. | [
"Suppose two black holes have the same masses, electrical charges, and angular momenta, but the first black hole was made by collapsing ordinary matter whereas the second is made out of antimatter; nevertheless, then the conjecture states they will be completely indistinguishable to an observer \"outside the event ... |
why does methamphetamine use ruin your teeth? | It causes your mouth to be very dry due to reducing the production of saliva. Saliva helps keep your mouth cleaner and flush away sugars, acids and food particles. Without it, decay can happen much more easily.
Amphetamines can cause or worsen teeth grinding also, which may play a part. People on days long meth benders also tend to forget about insignificant matters like brushing their teeth and often favor lots of sugary and acidic drinks rather than actual food.
It's all a perfect storm for tooth decay. | [
"Hydrochloric acid is used in methamphetamine's manufacturing process, but academic reviews have not supported the idea that the acid contributes to dental decay. Speculation that oral consumption of the drug causes tooth decay by raising the acidity of users' mouths is also unsupported. Meth mouth is generally mos... |
how do search dogs track scents? | Let's say they have a piece of your clothing. The dog is trained to follow a scent that is given to it, so they let it smell your clothing, then using its extremely acute sense of of smell it is able to follow the scent of the clothing you have on you. A smart criminal abandons any clothing it knows can be used to be tracked down by dogs. | [
"One notable quality of detection dogs is that they are able to discern individual scents even when the scents are combined or masked by other odors. Many items that dogs can detect can be disguised when covered by multiple scents. Detection dogs help uncover these items. In 2002, a detection dog foiled a woman's a... |
In l’Hospital’s Rule, Why is the limit of a function the derivative of f(x) divided by the derivative of g(x)? Isn’t that like saying: to determine a person’s location you must know their speed? | L'Hopital's Rule has nothing to do with position, speed, or any physics whatsoever. First of all, it is not true that the limit of f(x)/g(x) is equal to the limit of f'(x)/g'(x). You need some conditions. The simplest proof is for the case when f(a) = g(a) = 0. Then we have
> f(x)/g(x) = [(f(x)-f(a))/(x-a)] / [(g(x)-g(a))/(x-a)]
So taking the limit x -- > a immediately gives f'(a)/g'(a) on the right side since that's just the definition of the derivative. (Of course, there are some caveats to L'Hopital's Rule, e.g. f and g have to be real-valued and the limit on the right has to exist for you to be able to say the two limits are the same. Also, we can extend L'Hopital's Rule to the case of ∞/∞.) The full proof uses the *generalized mean value theorem*.
What the theorem ultimately comes down to is that if f and g are sufficiently nice near x = a, then
> f(x) = a*_0_* + a*_1_*(x-a) + a*_2_*(x-a)^(2) + ...
> g(x) = b*_0_* + b*_1_*(x-a) + b*_2_*(x-a)^(2) + ...
If f(a) = g(a) = 0, then a*_0_* = b*_0_* = 0. So then you can cancel a factor of (x-a) in the quotient f(x)/g(x) and get that the limit is a*_1_*/b*_1_*, which is just f'(a)/g'(a). | [
"which when taken to the limit as \"h\" approaches 0 gives the derivative of the function \"f\". The name of the expression stems from the fact that it is the quotient of the difference of values of the function by the difference of the corresponding values of its argument (the latter is (\"x\"+\"h\")-\"x\"=\"h\" i... |
the driving force behind evolution. | Evolution is based on the idea of "natural selection". Let me explain what exactly happens with DNA first.
Every living thing has DNA, which has a lot of pieces arranged in a certain way. The DNA is like a map for how everything is built. A human and a dog have DNA that makes sure they have legs, but a human has DNA for only 2 legs and 2 arms, while a dog has DNA for 4 legs.
To be safe, your DNA comes in doubles. Every piece has a copy. The sets of copies are chromosomes. Humans have 23 sets, or 46 total. All living things have these in every single cell too, so humans have 23 sets of DNA in every cell in their body.
When people have kids, they basically mash up their copies and put them back together together while the mom is pregnant. Some pieces come in from the dad's DNA, some from the mom's. If everything goes like it should, the baby then has 23 sets of a new combination of chromosomes. Some parts of the maps look like the mom's, and some look like the dad's, but they are rarely the same.
Things don't always get copied properly, and the DNA can have spontaneous new codes in it. Thing can happen in a lot of ways (usually mistakes in copying, very strong chemicals, and so on), but it means the code is different because of something other than a mom and dad making a baby. That is called a mutation, regardless of whether it's good or bad. If you have enough mutations in the DNA, it can change something about the living thing it's in. For example, a mutation that grows fins.
Natural selection is all about those mutations. Mutations are pretty common, and not all of them even do anything. Some mutations can cause things to die, but some can make their lives easier. Some ways mutations can help things can be either to make it easier to get food and water, or they can mean making babies is easier.
Natural selection is exactly that effect. Any mutations that are bad aren't likely to go onto the babies, because they make it harder for the mom or dad to have babies. Some mutations that don't happen until old age can still get passed on, but any mutation that affects growing up or having babies can usually get weeded out.
It works the other way too. A mutation that makes it easier to have babies means that the things with it will probably have more babies. That means that later on, there's more moms and dads with that mutation that have more babies than people without.
Natural selection is not a conscious thing. It's not like there's a person watching it happen and making sure things are going according to a plan. It's called natural because it happens without anyone forcing it too, and it's called selection because it's *like* someone is picking out the good and bad, not because someone actually is doing that. | [
"The term \"evolution\" was introduced into the scientific lexicon by Jean-Baptiste de Lamarck in 1809, and fifty years later Charles Darwin posited a scientific model of natural selection as evolution's driving force. (Alfred Russel Wallace is recognized as the co-discoverer of this concept as he helped research a... |
what is icann and why everyone is freaking out over the us ending their contract with them? | In short (I'm over-simplifying here) the ICANN takes care of internet addresses. This has been in the US for years, but after the NSA spying scandal they decided it was time to make some changes. See also: _URL_0_
It was always the plan to be global, and not tied to one specific country's government. It was never going to stay in the US forever. | [
"On July 26, 2006, the United States government renewed the contract with ICANN for performance of the IANA function for an additional one to five years. The context of ICANN's relationship with the U.S. government was clarified on September 29, 2006 when ICANN signed a new Memorandum of Understanding with the Unit... |
What might the earliest human languages have sounded like? | We have no idea.
Some people are saying "Click languages!", based on [this](_URL_3_) research, which claimed to show that phoneme density went down the farther you got from Africa. But there were some serious methodological issues with that paper- mainly, their definition of "phoneme". Despite what we teach y'all in Ling 101, it's actually very difficult to get agreement on phoneme counts for languages.
In any case, the time depth for human language (low end is 30,000 years, high end is a million) is just way too deep to try and reconstruct a "Proto-World" language- the usual method we use for reconstructing the sounds of language, called *comparative reconstruction* only gets us so far- maybe 6000 years, at best. Even in the languages we know the most about the mother language for- Indo-European languages- we have huge, unanswered questions. For example, we think that there are these things called *laryngaels*, whose existence we mostly posit through vowel quality changes (and some evidence from Hittite), but we have no consensus on (1) how many of them there were, or (2) what they sounded like.
What people like Ray Jackendoff who try and answer this question are concerned with, however, is not reconstruction, or even with trying to look at "older languages" (a distinction that really has no meaning in linguistics- all languages, except the dead ones, are equally old) but rather what appear to be "simpler" forms of language: the speech of people with aphasia, early stage Pidgins, Basic Variety of second language learners, the communicative devises of primates and other animals, the speech of feral children and (the signed speech) of deaf children raised without sign language. From there, they posit, we can get an idea of what *Proto-language* might have looked at. But all of these methods have controversies, and people argue a great deal about the validity of their conclusions.
EDIT: Ray Jackendoff's homepage [here](_URL_1_), with information about his work on language evolution.
Language Log post reacting to the paper on phonemic density [here](_URL_0_). As they say: intriguing, but defining "phoneme density" is really, really hard, and it's not clear that Atkinson did it correctly.
Review article responding to Greenberg's claims that massive comparison to reconstruct Proto-World is possible [here](_URL_2_). | [
"The discovery of Turkana boy (\"H. ergaster\") in 1984 evidenced that, despite its \"Homo sapiens\"-like anatomy, \"ergaster\" may not have been capable of producing sounds comparable to modern human speech. It likely communicated in a proto-language lacking the fully developed structure of modern human language b... |
What happened to the rail network of the US? | For the most part, it’s still around. The US doesn’t have construction of railways because we already have lots of them. All the big transcontinental routes you read about from the 19th century are, for the most part, still in place (with some adjustments).
There has been some contraction, though. There are two interrelated factors here. One is the rise of modern trucking. While rail is, on a per-mile basis, more efficient, it does not beat trucking in all respects. Not every manufacturing plant has rail access. Nor does it really work economically to ship smaller items by train, compared to trucks—you can have a truck drive a small piece of industrial equipment from one place to another directly, but a single traincar load will be collected by a local train that picks up from industrial tracks, perhaps be arranged into a mixed freight train to another area, then dropped off by another local train. This takes much longer than simply loading a truck.
This was greatly accelerated by the interstate highway system in the mid-1900s, which made that trucking infrastructure much faster. And that infrastructure was government-funded, both in its construction and maintenance (though many major rail lines had their construction subsidized too). Some routes were no longer economically feasible, when rail was not the only shipping option.
The other factor is the consolidation of American railroads. Because of the rise of interstate trucking, some monopoly concerns for railroads have diminished, and more railroads have merged. Because of this some railroads have merged and closed duplicate routes. But that’s not always true. In the Northeast, for instance, there are two complete routes from New York to Washington DC—one built by the Pennsylvania Railroad, and the other in pieces from the Baltimore & Ohio, Reading, and Central Railroad of New Jersey. Both are still in use, the former by Amtrak and various commuter railroads, and the latter as a freight route (with some commuter service).
If you’re asking about passenger railroads, the story is mostly the same, but to a greater extent. Air travel was much faster than rail, and car travel was faster particularly for short distances, and in newly built suburbs that may or may not have had rail access. Railroads were in serious financial trouble in the mid-1900s, and their passenger service was losing money. Regulations forbade them from closing this service, even if they were little-used and there were other transportation options in the area. In the 1970s the government allowed railroads to hand over this obligation to Amtrak, a government-formed passenger railroad, which would operate this service over other railroad’s tracks. Amtrak was able to close duplicate or lightly-used service. After airline deregulation made air travel much cheaper than it had been in the 1970s.
There has been relatively little construction of new routes in the US, but that’s mostly because the network already exists. Apart from high-speed networks, very little new rail has been constructed in the last several decades. Many routes were constructed when rail was the only feasible option for transport, there aren’t many routes that make sense now that didn’t make sense when the US was building railways. | [
"Railroads have been abandoned in the United States due to historical and economic factors. In the 19th century, the growing industrial regions in the Northeast, the agrarian regions in the South and Midwest, and the expansion of the country westward to the Pacific Ocean all contributed to the explosive growth of r... |
1) why is there gaps or spaces between galaxies? 2) what fills these gaps or spaces? 3) why aren’t galaxies connect like a web or something? | Galaxies *are* connected like a web or something [if you zoom out enough to see it](_URL_2_). It's important to note that the blobs of light in that image are *not* galaxies. They're *clusters* of galaxies, or superclusters, which can contain *thousands* of galaxies.
Consider the organization of the solar system. Most of the matter that formed the solar system became the Sun, and the rest spread out over a [huge distance](_URL_0_). That matter is pretty concentrated in local spots, which are the planets. The space between planets is pretty empty, of course, but it still has a lot of stellar dust particles and comets and asteroids and a lot of *stuff*. But compared to the density of matter on Earth, interplanetary space is *really* empty.
Then again, compare the density of matter within the solar system to the space between our solar system and the next one. The solar system has a ton of matter. Several planets' worth. But there's less between us and the Alpha Centauri system. It all seems random and empty until you zoom out and look at the galaxy and see the [spiral arms](_URL_1_) that show the organization of the local groups of solar systems. It doesn't look like there's a lot of stuff between us and Alpha Centauri, and there's not, but when you look at the bigger picture you see that, in fact, there's still a *lot* of stuff pretty close together. And there is a lot of dust and rocks and stuff out there, too.
And you can zoom out again to see the nearby galactic local group. Then the Virgo Supercluster. Then, finally, the structure of the universe as far as we know it.
In the empty voids between galaxy superclusters, there's sparse traces of dust and gas, but that's it. The rest of the matter is concentrated in the superclusters. And within the superclusters, most of the mass is concentrated in the galaxies. And so on. | [
"When two galaxies pass by each other in close proximity, their shapes distort due to each other's gravity. The outside spiral arms splay out into space, often casting stars and dust into the abyss as their host galaxies drift slowly back towards each other in orbit. These spiral distortions are called tidal arms, ... |
Is there a certain density needed for gravity? | There is no theoretical minimum but (above and) below certain masses and (above and) below certain length scales there haven't been experiments. | [
"Unlike density, specific weight is not absolute. It depends upon the value of the gravitational acceleration, which varies with location. Pressure may also affect values, depending upon the bulk modulus of the material, but generally, at moderate pressures, has a less significant effect than the other factors. \n"... |
why dvd ripping is "not okay" and cd ripping is | The DVDs you have problems ripping are using [Content Scramble System](_URL_0_). This a system in which the video material is scrambled/encrypted, and the key to unscramble it is stored on a special part of the disc called the lead-in. When you put a commercial DVD in your player, it first finds the key, and then uses it to unscramble your video.
DVD burners cannot write to this lead-in area, so when you try to make an exact copy of a DVD, it will not copy the keys across. And of course, without the key, your player cannot correctly play the video.
The 'special software' you need to make a copy is simply software that, rather than making an exact copy of your scrambled DVD, looks at the keys, unscrambles it, and makes a copy of the *unscrambled* DVD instead.
CDs do not have restrictions like this, presumably either because their piracy was not anticipated, or because the processing power required by an encryption scheme was unreasonable to include in a 1985 stereo. | [
"There are also DVD rippers which operate in a similar fashion. Unlike CDs, DVDs do contain data formatted in files for use in computers. However, commercial DVDs are often encrypted (for example, using Content Scramble System/ARccOS Protection), preventing access to the files without using the ripping software's d... |
How does Atomic Force Microscopy (AFM) works inside liquid? | I’m not exactly sure what you’re asking, but in general it works the same way as it does in air, but with some caveats.
In air, you scan the tip, which is at the end of a cantilever, over your sample. At the same time, you bounce a laser off of the back of the cantilever and to a detector, so that you measure what’s happening to the tip (is the tip being deflected up, sideways, etc) Depending on the AFM imaging mode, you pick a parameter (or several) and try to maintain a feedback loop.
As an example, if you’re in AM (amplitude modulation) mode, you’re measuring the amplitude of the cantilever moving up and down, and comparing it against the set point. If the amplitude is larger than your set point, the z piezo will move the tip and sample closer together to reduce the amplitude, and get it to the set point. If the amplitude is smaller, then the z-piezo will move the tip and sample further apart to increase the amplitude.
In liquid, this works the same way, however
1) you have to take into account how the laser refracts when it goes into the water, so your optics have to be adjusted.
2) You’re also going to use a softer cantilever (with a lower spring constant) because you’re now driving the cantilever in liquid, which is also going to dampen your oscillation.
3) depending on the AFM, you’ll have to pay attention to the liquid evaporating; otherwise your parameters may change and shift and mess up your feedback.
4) Additionally your buffer may change how your sample interacts with your substrate, and how your sample interacts with the tip.
Hope that helps!
| [
"Atomic-force microscopy (AFM) is a powerful microscopy technique used for studying samples at a nanoscale and is often used to image protein distribution on a surface. It consists of a cantilever with a tip to scan over the surface. It is a valuable tool for measuring protein-protein and protein-surface interactio... |
Is the color red lucky in China because of tradition, or because Communism is associated with the color? | This question is not really a good question for /r/AskHistorians as this particular question is more of an anthropology question. That said:
Red as a symbolic color in China has always been considered culturally lucky and associated with joy way before the Communist Revolution in China. The color red is used a lot in old architectural design and is especially used in decorations for the Spring Festival (Chinese New Years, which has a focus on luck in the **New Year**, thus the **future**) as well as for weddings (luck for your married **future**). Red is also considered taboo to wear at funerals since red is considered a happy color and is considered improper to wear during a time of mourning. The idea of Red being the color of the Bolshevik movement was imported from the USSR and the coincidence of red being lucky and a symbol of Lenin's movement was not unnoticed by the Chinese. For instance there is the famous song and ballet/film called the "East is Red" which champions Mao and Chinese Communism comparing them to the "red" rising sun which symbolizes a new and more joyous "dawn" and **future** for China under the leadership of Mao. For the West the color is more so associated with Communism in general but in China the coincidence gave an opportunity for a useful propaganda device to encourage people that Communism was the source of where their bright future is coming from. So yes the two are fundamentally tied together but only because of the previous cultural association and not because it was later implemented. | [
"In China, red () is the symbol of fire and the south (both south in general and Southern China specifically). It carries a largely positive connotation, being associated with courage, loyalty, honor, success, fortune, fertility, happiness, passion, and summer. In Chinese cultural traditions, red is associated with... |
how it is not discrimination for offering race specific scholarships. | It is discrimination -- it's publicly acceptable (and completely legal) discrimination. | [
"The scholarship is open to students in all disciplines, including business, engineering, law, medicine, sciences, and humanities. There is also no discrimination on the basis of race, color, religion, national origin, gender, age, or disability in choosing awardees.\n",
"The Whites Only Scholarship was founded i... |
why do water droplets reflect their surroundings upside down? | The water droplets act like a converging lens. When you are close enough to a water droplet to see the reflection clearly, you are still outside the focal length, so the image appears upside down and stretched out. Were you able to get *very* close (and have there still be enough light to see), you would actually see the normal reflection - the right size and right side up. | [
"The high surface tension of water causes droplets to assume a nearly spherical shape, since a sphere has minimal surface area, and this shape therefore demands least solid-liquid surface energy. On contact with a surface, adhesion forces result in wetting of the surface. Either complete or incomplete wetting may o... |
Regarding armed combat, was a dual wielding style ever used or maybe even advantageous? | Miyamoto Musashi was famous for mastering a dual sword technique if I'm not mistaken | [
"Dual wielding is using two weapons, one in each hand, during combat. It is not a common combat practice. Although historical records of dual wielding in war are limited, there are numerous weapon-based martial arts that involve the use of a pair of weapons. The use of a companion weapon is sometimes employed in Eu... |
Can mitochondria catch viruses? | "The self-destruction of cells infected with viruses undergoes the process of apoptosis generally to restrict infection and the spread of viral progeny. To avoid infection host has evolved interconnected complex defence network that comprises innate and acquired immune response. Mitochondria being considered as powerhouse of a cell is not limited to only energy production, but mitochondria perform various other functions in (disease, apoptosis and host innate immune system) which make them absolutely indispensable to the cell. This makes them a target of almost all the invading pathogens including viruses. Therefore being a multifunctional organelle, the viruses choose mitochondria as a favourite organelle as they can easily take control of the whole cell and make it to promote or block apoptosis as per their need."
_URL_2_
_URL_1_
_URL_0_
Couple of sources here for some reading on your own! | [
"isolated mitochondria (from cell cultures, animals or plants); permeabilized cells (from cell cultures); and permeabilized fibers or tissues (from animals). In the latter two cases the cellular membrane is made permeable by the addition of chemicals leaving selectively the mitochondrial membrane intact. Therefore,... |
how red light therapy works | > Nothing about it makes sense to me. How does this work?
It is simple: Saps pay money for a red LED light and believe any pseudoscientific nonsense that is tossed their way. The scam artist makes a load of money off this fad.
Of course it doesn't do anything, there is no evidence that the "therapy" works, but that doesn't stop them being really popular with those who don't have the ability to assess the truth value of health claims. You know, like people who go to chiropractors or take homeopathic remedies. | [
"Light therapy uses either a light box which emits up to 10,000 lux of light at a specified distance, much brighter than a customary lamp, or a lower intensity of specific wavelengths of light from the blue (460 nm) to the green (525 nm) areas of the visible spectrum. A 1995 study showed that green light therapy at... |
Why is thick ice blue? | For the same reason that ocean water is blue. Water and ice both [only absorb weakly in the visible spectrum.](_URL_0_) However this absorption is stronger in the red part of the spectrum and weaker at the blue end. As a result, the intrinsic color of water and ice is blue. The problem is that in order to see it you need light to travel through a sufficiently thick layer of water/ice for the color to become noticeable. That is why a glass of water or an ice cube will look clear, but the ocean or a thick sheet of ice will look blue. | [
"Small amounts of regular ice appear to be white because of air bubbles inside them and also because small quantities of water appear to be colourless. In glaciers, the pressure causes the air bubbles to be squeezed out, increasing the density of the created ice. Large quantities of water appear to be blue, as it a... |
How is it possible to use flourine in toothpaste and how does it prevent decay? | Flourine vs flouride. Big difference!
Hydroxylapatite Ca10(PO4)6(OH)2 (I don't know how to do subscript on reddit, sorry) undergoes hydroxyl exchange with flouride to form flouroapatite. Fluoroapatite is much more resistant to acid mediated degradation. | [
"There are also many medications, which are used to treat tooth decay. Fluoride is used to prevent tooth decay in individuals. Fluoride is available in non-prescription form and is available in many different types of toothpaste.\n",
"Fluoride toothpaste is the most widely used and rigorously evaluated fluoride t... |
At which time did poland rename all their cities from German to Polish? Also, why did they rename them? | The current set of Polish borders are significantly different from the historical set of borders constituting what is "Poland". Poland existed as an independent state until 1795, when it was partitioned between Austria, Prussia, and Russia. Poland was revived as an independent state in the aftermath of WW1 but was then partitioned again by the Nazis and the Soviets under the terms of the Molotov-Ribbentrop pact, Stalin then annexed the eastern parts of the country into the USSR itself.
He then chose to "shift" the entire country westwards as the allies won WW2 against Germany, by giving it territory from Germany which had never being Polish before, this was followed by mass ethnic cleansing of the German population and the renaming of cities such as Stettin/Szczecin to help erase its German past and make it part of Poland.
| [
"All German names of streets, buildings, shipyards and districts, even names on tombstones, were changed to Polish names, such as \"Długi Targ\" for \"Langer Markt\" (Long Market), the city's main pedestrian center. The city districts were renamed, sometimes derived from medieval Polish records (Wrzeszcz, Siedlce),... |
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