source string | id string | question string | options list | answer string | reasoning string |
|---|---|---|---|---|---|
OpenBookQA | OpenBookQA-4401 | noise, digital-filters, filtering
If it was due to clock feed through (if other clocks are used in the system or are operating nearby) this would have been indicated by a tight spurious result (narrow tone) in the spectrum and if identified may be easy to resolve in the hardware directly (judicious shielding and bypass caps etc) or a notch filter in the signal processing such as demonstrated here.
The following is multiple choice question (with options) to answer.
If a thing has been taken from a large object and made much smaller, even minuscule, and this was done over many years, the likely culprit was | [
"gales",
"thought",
"aliens",
"dust"
] | A | wind causes erosion |
OpenBookQA | OpenBookQA-4402 | As far as your quote, the opposite can happen as well. You could have low pairwise correlations, but have high VIF's. This is because it's possible that there's a strong relationship between predictor $$i$$ and all the other variables together, even though there's not a high correlation between predictor $$i$$ any other predictor independently.
The following is multiple choice question (with options) to answer.
What relationship is most likely? | [
"birds eat giraffes",
"dandelions eat worms",
"petunias devour mice",
"wolves eat voles"
] | D | consumers eat other organisms |
OpenBookQA | OpenBookQA-4403 | zoology
Capybara, rabbits, hamsters and other related species do not have a complex ruminant digestive system. Instead they extract more nutrition from grass by giving their food a second pass through the gut. Soft fecal pellets of partially digested food are excreted and generally consumed immediately. Consuming these cecotropes is important for adequate nutritional intake of Vitamin B12. They also produce normal droppings, which are not eaten.
Young elephants, pandas, koalas, and hippos eat the feces of their mother to obtain the bacteria required to properly digest vegetation found on the savanna and in the jungle. When they are born, their intestines do not contain these bacteria (they are completely sterile). Without them, they would be unable to obtain any nutritional value from plants.
Eating garbage and human feces is thought to be one function of dogs during their early domestication, some 12,000 to 15,000 years ago. They served as our first waste management workers, helping to keep the areas around human settlements clean. A study of village dogs in Zimbabwe revealed that feces made up about 25% of the dogs’ overall diet, with human feces making up a large part of that percentage.
Coprophagia
Daily rhythms of food intake and feces reingestion in the degu, an herbivorous Chilean rodent: optimizing digestion through coprophagy
Coprophagia as seen in Thoroughbred Foals
The following is multiple choice question (with options) to answer.
Carnivores' only source of what comes from other animals | [
"flying",
"money",
"restaurants",
"sustenance"
] | D | carnivores only eat animals |
OpenBookQA | OpenBookQA-4404 | botany, entomology
Title: Health effect of worm in Guava I ate a ripe guava, rife enough to be broken with hand, i later saw that it has white worms with one black end crawling inside it, are these worm harmful, i had unripe guava of same batch though most of them had small black spot inside, but no worm crawling, what are these crawling worms, were they present in guava from unripe stage or infected only after ripening ? It is a safe bet that a "worm" as you describe in a ripe guava or any other ripe sweet fruit is a fruit fly.
from http://www.greenharvest.com.au/PestControlOrganic/Information/FruitFlyControl.html
Fruit flies are attracted to any ripe sweet fruit. They are also attracted to vinegar and alcohol - both produced by yeast in and on the fruit, which is the high protein food that the fruit flies are really after in the fruit.
from
http://homeguides.sfgate.com/treat-fruit-flies-guavas-30550.html
When ripe, guavas emit a pungent, musky odor that attracts fruit
flies. Fruit flies lay their eggs beneath the fruit's skin, and the
maggots feed on the flesh. The damage causes guavas to rot. Fruit fly
infestations often spread quickly, but prompt treatment can get
populations under control.
The fly large actually speed the rotting of the fruit by moving yeast around on their bodies.
The following is multiple choice question (with options) to answer.
An alien creature is found on earth. Researchers discover that it will eat worms, insects and small rodents, but shuns bananas, leaves and cucumbers. Which of these could be true? | [
"the creature is a carnivore",
"the creature is a vegan",
"the creature is something other than an omnivore",
"the creature loves to eat cucumbers"
] | A | carnivores only eat animals |
OpenBookQA | OpenBookQA-4405 | waves, energy-conservation, acoustics
Title: The sound energy when two or more objects collide When two objects collide in an inelastic collision, some kinetic energy is converted to sound energy and heat. How do I determine how much of the kinetic energy is converted to sound energy? Provided that I'm doing an experiment where I take the readings as seen in this question's answer.
I have tried to use the law of conservation of energy to do this:
$KE_{1i} + KE_{2i} = KE_{1f} + KE_{2f} + Sound Energy + Heat$
Since there is heat generated here, I cannot just compare the initial and final values of the kinetic energies. So, after reading this question and the answers I can now have an idea what the formula of the sound energy might be like.
$E\ \alpha\ \omega^2A^2$ where $ \omega = 2\pi f$
thus I can say $E\ \alpha\ 4 \pi^2 f^2 A^2$ ?
One problem is that the formula I found here is a proportional formula not a direct formula that is using an '=' sign so there might be some more constants added to the relationship.
I have read somewhere else that I am supposed to use sound energy density instead of sound energy, but I'm not sure if sound energy density could represent the whole energy conversion from kinetic to sound.
In addition, the reason I want to find the energy using frequency and amplitude as variables is that I want to see quantitatively the effect of increasing the speed of the objects to the amplitude of the sound produced. I know that every material has its own natural frequency on collision as seen from the coin dropping experiment.
So, what is the 'proper' way of finding the relationship between the amplitude and the speed of the objects (kinetic energy I suppose)? How much sound colliding objects make depends entirely on the objects and the medium they are in. In the vacuum of space collisions don't make a sound, at all. In Earth's atmosphere the total energy of sound released by collisions that are caused by solid objects is very small compared to the energy of the objects. This is because of the large difference in density between solids and the atmosphere.
The following is multiple choice question (with options) to answer.
An object converts electrical energy into sound on a | [
"iphone",
"soft carpet",
"outside wall",
"wooden table"
] | A | sound can travel through air |
OpenBookQA | OpenBookQA-4406 | botany, plant-physiology, plant-anatomy
It made me wonder if we are simulating the sun in a dark room for growing the plants with the help of red, blue, and a little bit of far-red light, what will happen to the plants if we keep the ideal conditions for which the plants carry out photosynthesis whole day? Does it affect its yield or the plants die out quick?
I am an engineering student working on indoor farming, my knowledge of botany is the same as a high school student. So if I am wrong please tell me. Ideal conditions for photosynthesis
You mention ideal conditions to carry out photosynthesis, I would just like to point out that this includes carbondioxide levels, temperature, and nutrients as well as light.
Flowering
As anongoodnurse mentions performance might be measured by blooming which, in most flowering plants, has a day-light related component. However, for general growth increasing daylight over the 'natural' day length can often increase yield.
Daylight Cycles
The important point to note is that plants do 'ramp up' at dawn getting ready to start photosynthesizing (for some plants with temporal photosynthesis mechanisms (see CAM photosynthesis) this can be even more important). The reason plants do this is because plants can suffer from 'photobleaching' which can be considered similar to sunburn in humans, if they are not ready for sunlight. Getting 'ready' can involve lots of things including opening stomata (pores) to let CO2 in, changing which metabolic pathways are active, and moving about chloroplasts inside cells. Plants 'figure out' how and when to ramp up based on circadian rhythms which work well on 24 hour clocks and slight changes over time. Thus 12 hrs to 16 hrs can be a big change, particularly if the change happens by lights coming on earlier. Additionally, the 24 hour 'clock' means that plants will do better with 18hr light then 6hrs dark cycles than 36hrs light 6 hrs dark, because the total cycle length should be about 24hrs.
Photosynthesis Side Effects
The following is multiple choice question (with options) to answer.
What requires sunlight to grow? | [
"lakes",
"deep sea fish",
"rose bushes",
"mountains"
] | C | a plant requires sunlight to grow |
OpenBookQA | OpenBookQA-4407 | botany
Title: Do plants absorb toxins from the soil? Consider a plant like Aloe Vera that grows up in a toxic environment where the concentration of pesticides, and materials like lead, mercury, cadmium, arsenic etc is very high(e.g. Marshland dumping yard ). Would that mean that the extract from these plants would contain all these toxic elements. Not "all of them". But yes, plants suck up water from the soil, with everything dissolved in this water - nutrients, heavy metals, poisons. And also they breathe air, and absorb stuff via this route.
There probably are some toxins which will not enter the plant, because their molecules are too large and/or fragile. For example, should a plant root come in contact with snake venom, I cannot imagine that any venom will end up stored in the plant leaves.
Plants also have their own metabolism, so they will change/deactivate some toxins. I've seen claims that some plants "purify" formaldehyde, although I don't trust the sources enough to be sure of that.
But the smaller the poison molecule, and the less similar to stuff which is usually digested in nature, the more likely that it will enter the plant and stick around instead of being broken down. The heavy metals you mentioned are prime candidates. If they are present in the groundwater - or also lead from air pollution, before we banned leaded gasoline - they end up in plants, including food plants. And mushrooms are even more at risk.
Growing food near waste dumps is a known problem in farming, and sometimes makes the news, for example here:
http://bigstory.ap.org/article/mafia-toxic-waste-dumping-poisons-italy-farmlands
The following is multiple choice question (with options) to answer.
In order for crops to grow food safely, pesticides are used on them. When it floods, this causes what to be poisonous? | [
"air",
"farmers",
"Corn",
"Runoff"
] | D | crop rotation renews soil |
OpenBookQA | OpenBookQA-4408 | resources, soil
Title: Is soil a renewable resource? My geology textbook tells me that soil is not renewable, and I agree with this, but there was some question in my class as to whether this is true.
Some soils take more than a human lifetime to regenerate. However, in crop production, it seems as if soil can be regenerated with additives.
In the scientific community of soil scientists, is soil considered a renewable resource by most of those scientists? Is there strong evidence to support this? Soil is an interesting case because although it is non-renewable (at any useful rate) as a 'bulk material' once removed from the ground, the nutrient content of soil can be renewed with fertilizers.
What a soil-scientist would understand as 'soil' is ultimately produced from the physical and chemical breakdown of solid bedrock at the base of the soil horizon. The rate at which this happens for natural soil production can vary substantially depending on the climatic conditions and other factors, but typically could range from 0.1 to 2.0 mm/yr.
In many intensively farmed regions, (top)soil is being removed by erosion much faster than it is being replaced by natural process. Removal of vegetation cover is enough to expose bare soil to rainsplash erosion at rates much greater than it is renewed. Once soil is bare, it becomes much more susceptible to erosion.
I think the additives you are referring to replenish the nutrient content of the soil, and not the the bulk material that would be produced by bedrock decomposition. With careful management, the fertility of existing soil can be maintained. But if the soil is allowed to be washed off or erode, for all practical purposes, the rate of replenishment is not fast enough for it to be classed as renewable in that sense.
This site has links to more aspects surrounding this issue.
The following is multiple choice question (with options) to answer.
The only resource that is replenished every time there's a hurricane is | [
"H2O",
"gas",
"oil",
"coal"
] | A | water is a renewable resource |
OpenBookQA | OpenBookQA-4409 | mountains, geography, paleogeography, isostasy, mountain-building
Title: What were the tallest mountain ranges in Earth's geological past? There have been numerous episodes of mountain building in Earth's geological history, particularly through the super-continent cycle. Many mountains and mountain ranges have been eroded, as mentioned in the similar question Determining the paleoelevation of mountain ranges.
What are believed to be the tallest mountain ranges in Earth's geological past? Additionally, what evidence is there to support these palaeoelevations? Factors determining the maximum possible height of mountains include the rate of uplift versus the rate of erosion[a] and rock strength.
Rock strength is controlled by the type and internal structure of the rock in question. There is some evidence that once mountains extend above the snow line, glacial and periglacial erosion have a stronger control than exhumation/uplift rate (Brozovic et al, 1997; Egholm et al, 2009).
Everest and the Himalaya have reached their maximum possible elevation: the formation of the Tibetan plateau is due to the failure of rocks preventing the maintenance of discrete mountain peaks. The principle of uniformitarianism suggests that - subject to differences in variables discussed by Egholm et al, including crustal composition - the Himalaya and Tibetan plateau are an excellent approximation to the maximum achievable height of mountain ranges. However, identifying which specific palaeoranges were tallest (as opposed to calculating a plausible upper limit on height) is a significantly harder problem to solve.
[a] Though note that the rate of erosion increases as the rate of uplift increases - for more on erosional equilibrium, see e.g. Riebe et al (2000).
The following is multiple choice question (with options) to answer.
The elements changed America's tallest peaks into | [
"marble blocks",
"ivory castles",
"towers of gold",
"loose rocks"
] | D | break down means change from a whole into pieces |
OpenBookQA | OpenBookQA-4410 | planets, orbital-motion, stars
Title: Could there be a star orbiting around a planet? I wonder if there ever could be a star (really small) which may orbit around a planet (really big)? One thing to keep in mind is that objects that are bound gravitationally actually revolve around each other around a point called a barycenter. The fact that the earth looks like its revolving around the sun is because the sun is much more massive and its radius is large enough that it encompasses the barycenter. This is a similar situation with the Earth and Moon. If there were three bodies, where two bodies were of similar size (like a binary star system plus a massive planet) then an analysis of three body systems shows that there are stable configurations where the objects will be in very complicated orbits where it would be difficult to say one orbits the other.
Update: The short answer is yes, it is possible when you look at the complete dynamical system, for the reasons stated above. More evidence of this can be found in the study of regular star orbits where very complicated orbits are possible and can be stable. Currently the cut off for classification of a planet and a brown dwarf is 13 Jupiter masses, which is arbitrary to some degree. The lightest main sequence stars have a mass of 75 Jupiters. This will put the barycenter well outside the radius of either body for binary systems.
A quick check of the two body system using the equation:
$$R = \dfrac{1}{m_1 + m_2}(m_1r_1 + m_2r_2)$$
Setting $m_1 = 75$, $r_1 = 1$, $m_2 = 13$, $r_2 = 2$ gives:
$$\dfrac{75 + 26}{75+13} = 1.147$$
Indicating a barycenter at roughly $\dfrac{1}{7}$ the distance between the objects. More bodies will cause more complicated orbits, where again, it would be difficult to say which object orbits which. It should be noted that if the system was composed of 3 objects, 2 of which had similar mass, it would be possible to develop a system that appears to have two larger objects orbiting a third smaller object. A quick check reveals:
The following is multiple choice question (with options) to answer.
If a thing is near a planet, yet a planet is orbiting something else, the orbiting item circling the planet is likely | [
"luna",
"the Sun",
"bees",
"coal"
] | A | a satellite orbits a planet |
OpenBookQA | OpenBookQA-4411 | species-identification, entomology
Title: What is this sand covered insect? I have found in a wooden house, in the mountains of central Spain this very curious insect:
I was wondering if that was its skin or whether it's decomposition or sand or saw-dust. That particular region of Spain does have stink-bugs ... but this one doesn't look like anything I've seen before. A google image search returns mostly arachnids ... but it seems to have only 6 legs. It's a kind of assassin bug, specifically a Masked Hunter:
The surface of an immature Masked Hunter is sticky and it attracts lint and dust which helps to camouflage this predator.
and
The name refers to the fact that its nymph camouflages itself with dust.
Though they feed on small insects, they will bite defensively, and when they do, it's fairly painful.
The following is multiple choice question (with options) to answer.
A series of small holes that lead to various locations are found in soil where these legless things burrow: | [
"frogs",
"moles",
"earthworms",
"salamanders"
] | C | earthworms create tunnels in soil |
OpenBookQA | OpenBookQA-4412 | plate-tectonics, crust, mantle, cavern
Title: How likely are caverns inside the mantle? Almost everyone wrongly assumes that the Earth's mantle is liquid, but it isn't (only the outer core is). Is it possible then that there are hollow spaces within the mantle, similar to caves in the crust? What could they look like and up to how much of the mantle could be hollow? What might be inside mantle caverns? Would they be filled with gas or rather vacuum? It is extremely unlikely that any hollow volumes exist in the mantle.
The mantle is a convecting solid which can deform over long timescales. Let's assume that such a cavern did somehow form. Whatever it is filled it, would be of lower density than the surrounding rock. It would slowly rise upwards through the solid-yet-deformable mantle until it reaches a place where the rocks are brittle, not ductile. That place is the crust. And as you know, the crust is full of caverns and there is no problem with that.
The following is multiple choice question (with options) to answer.
The mantle is | [
"anger",
"magic",
"passion",
"solid bulk"
] | D | the mantle is a layer of the Earth |
OpenBookQA | OpenBookQA-4413 | • Are you assuming that there are 1017 people in the building? And that all are not born on July 15. Or are you saying there are $n$ number of people in the building, 1017 weren't born on July 15 and $n -1017$ were? – fleablood Oct 6 '18 at 19:29
• "assuming that the year is not a leap year." I'm going to nitpick that whether this year is a leap year has no bearing whatsoever when someones birthday is. My birthday is the same this year as it was in 2016. If I had been born on Feb 29 on a leap year that would still be my birthday no matter what year you asked me..... – fleablood Oct 6 '18 at 19:33
• @fleablood If it was a leap year, I would have 366 days in total - that's all I meant - and the problem mentioned to assume that it was not a leap year if anyone was confused. – geo_freak Oct 6 '18 at 19:36
• ... that said, we can say "for simplicity we can ignore leap days" or we can say that ans 1 in $4*365+1$ the probability of not July 15 is $\frac {4*364 + 1}{4*365 + 1}$ But that is close enough to $\frac {364}{365}$ to not be fussy. After all, Not every day is equally likely (just look at any census) and the assumption that they are equal is no more inaccurate than the rounding down. – fleablood Oct 6 '18 at 19:38
The following is multiple choice question (with options) to answer.
If a person's age is celebrated in adulthood, then it happens every | [
"12 months",
"24 days",
"six weeks",
"twelve hours"
] | A | one year is equal to 365 days |
OpenBookQA | OpenBookQA-4414 | energy, acoustics, friction, resonance, perception
Title: What frequency is the scratching of finger nails on a blackboard? This is the frequency/intensity that sets my teeth on edge.
Does anybody know what frequency (roughly) it is? I am guessing it is near the top of normal human hearing, 20kHZ, but I'm not sure if that's why it affects me.
I am sure the same frequency is played on some of the music I listen to, but somehow, it does not make me wince.
There is a related question here, with no answer Scratching on a Blackboard, but I just want a frequency value. From http://www.livescience.com/16967-fingernails-chalkboard-painful.html:
Interestingly, the most painful frequencies were not the highest or lowest, but instead were those that were between 2,000 and 4,000 Hz. The human ear is most sensitive to sounds that fall in this frequency range, said Michael Oehler, professor of media and music management at the University of Cologne in Germany, who was one of the researchers in the study.
No one knows all of the reasons why that sound is so painful to listen to, but some theorize that we evolved ear canals to amplify human speech as much as possible, and that sounds like this happen to have large portions of their energy in that frequency band.
The following is multiple choice question (with options) to answer.
Which is likeliest to be torn by human hands? | [
"wood",
"steel",
"taffy",
"diamond"
] | C | tearing means changing a whole into pieces |
OpenBookQA | OpenBookQA-4415 | everyday-life, material-science
Title: Why can we tear a newspaper neatly one way but not the other way? When I try to tear the newspaper from top to bottom (or bottom to top), it's torn pretty neatly and like a line, but when I try to tear it from side to side, it goes all over the place and tries to lead the tear towards the top or bottom.
Why does this happen? Newspaper is made out of cellulose fibres (linear unbranched ones) bonded entangled together.
The fibre structure is anisotropic. The orientation of most of the fibres is along the direction of the movement of the machine.
In the direction of this orientation, it is relatively easier to tear a newspaper because it's just a matter of prying two fibres apart. (without significant tearing of fibres)
In the direction perpendicular to this, fibres have to be broken to tear the paper, and this requires a greater force.
The same asymmetry account for why tears are neat/messy depending on the direction you take.
If a piece of paper was isotropic, with random orientation of fibres, tearing would roughly take the same effort in any direction.
The following is multiple choice question (with options) to answer.
People often tear | [
"rain",
"evaporation",
"voltage",
"private documents"
] | D | tearing means changing a whole into pieces |
OpenBookQA | OpenBookQA-4416 | climate-change, paleoclimatology, solar-terrestrial-physics
Summarizing, the IPCC consider solar irradiance variations, the timing of solar minimums and maximums. However, it consider also many other factors that also affect Earth's energy budget. Then, they do predictions based on the combined effect of all these factors. In contrast, some people tend to focus on just one factor (as solar activity) and erroneously assume that it will dominate over all the others.
For the particular case of solar activity, as you can see in the cites above. The IPCC acknowledge the possible occurrence of a solar minimum in the future, but combining all the models they conclude that there is a high confidence that its effects will be much smaller in magnitude than the projected increased forcing due greenhouse gases.
Part of the reason your question might not be well received is because it starts from an assumption that is false: "climate experts from the UN/IPCC never mention Grand Solar Minimum". They do mention it, and if you follow the references in the IPCC you will find plenty of discussion about Dalton, Maunder and older Grand Solar Minimums. And part of that discussion is to estimate the real impact that those events can have in Earth's climate. Then the IPCC get those estimates and figure out how they interplay with the many other factors that conjugate to determine current and future Earth's climate.
The following is multiple choice question (with options) to answer.
Which would likely lessen the impact of climate change the most? | [
"Earth Day",
"hurricanes",
"tsunamis",
"wildfires"
] | A | planting trees has a positive impact on an ecosystem |
OpenBookQA | OpenBookQA-4417 | habitable-zone
Title: Better than Earth habitability Earth undoubtly has very good conditions for supporting life. Although it is expected that many other planets on the outer space have conditions at least as good as Earth, the vast majority doesn't, making them unhospitable to life or probably being able to support only very simple lifeforms. Earth itself for some billions of years until the Ediacaran or Cambrian could only support very simple lifeforms.
There are many parameters that may influence the habitability of a planet and its ability to support complex life: Star type; star temperature; star luminosity; stellar activity; stellar stability; star age; planet age; planet composition; planet size; orbital excentricity; orbital length; rotation axis inclination; planet tectonics; planet magnetosphere; presence and influence of satellites; abundance of water; planet atmosphere; interactions with other planets; presence or absence of asteroids, comets and minor planets planets belts and their position, distribution and composition; galactic orbit; galactic neighborhood; mass-extinction events rate, probability and intensity; and hundred of other possible variables including some based on pure luck and random chance.
Many of the parameters are modeled after Earth itself, since Earth is the only place so far that we know that life exists, and even if we found some alien life somewhere, it will probably be limited only to very simple forms of life.
But, what combinations of those parameters could lead to a planet with better life support than Earth itself?
Ok, you may argue that the question is too broad, so by "good life support" we could say something that allows the planet to evolve plenty biodiverse multicellular life ranging from simple microscopic creatures to complex dozens-meters long creatures with many body-differentiated parts and organs in a short timespan. So, a planet that has an environment which allows the development of richly-diverse and complex plant-like and animal-like creatures in a billion years after formation and stay like this for another 10 billion years is expected to be more life-friendly than Earth.
Further, lets restrict the biochemistry to what we know: water-based and carbon-based life, but not necessarily oxygen-breathing.
By the way, I am not asking anything about intelligent life or humans, just complex multicellular and biodiverse life.
The following is multiple choice question (with options) to answer.
If a habitat that supports itself is flourishing, improvements may still be made by | [
"burying small oak pips",
"using pesticides fairly regularly",
"setting uncontrolled wild fires",
"setting out mouse traps"
] | A | planting trees has a positive impact on an ecosystem |
OpenBookQA | OpenBookQA-4418 | optics, visible-light, quantum-electrodynamics, reflection
Title: Is the glass made up of holes that let the light to go through it? The following passage has been extracted from the book "The Magic of Science-A.Frederick Collins" (1917):
Substances of all kinds
have pores or holes in them. A sponge has pores that can
be seen and so has cheese, be it
green or yellow; and so, too,
have glass and metals, but the
pores or holes in the latter are so
small that you couldn't see them
even with a high-powered microscope,
but in glass they are
large enough to let light go
through them and in metals they
are large enough to let electricity
flow through them.
The following passage has been extracted from the book "QED:The strage theory of light and matter-Richard P Feynman" (around 1983-1985):
There are several possible theories that you could make up to account for the partial reflection of light by glass. One of them is that 96% of the surface of the glass is "holes" that let the light through while the other 4% of the surface is covered by small "spots" of reflective material. Newton realized that this is not a possible explanation.
Aren't the two passages in contradiction with each other?
Frederick says that glass is made up of holes that facilitates the passage of light through it, on the other hand Feynman is not ready to come in agreement. I think Frederick is little sloppy. Isn't it? Today we know that Collins is wrong.
He appears to be unaware of Newton's finding, and of course, advances made after he wrote his book.
The following is multiple choice question (with options) to answer.
objects made of what cause refraction of light? | [
"wind",
"wood",
"melted sand",
"soil"
] | C | objects made of glass cause refraction of light |
OpenBookQA | OpenBookQA-4419 | refraction, geometric-optics
This requires a refractive index just greater than 1.7 ($1/\sin(36)$ - definitely possible.
If you are willing to have the exit direction ($a_4$) be something other than zero, then you can improve on the above solution (make it possible with lower refractive index).
The following is multiple choice question (with options) to answer.
Which would least refract light? | [
"a cardboard box",
"a bottle",
"a gem",
"a diamond"
] | A | objects made of glass cause refraction of light |
OpenBookQA | OpenBookQA-4420 | classification
Title: What order is this butterfly?
I found this butterfly in the rocky mountains of colorado. Its obviously a lepidoptera but I'm not sure what family this butterfly could be. I found it perched on a bush and it is around 40ish mm long. Thank you very much for any answers, making an amature insect collection :3
Edit: I was thinking its a Riodinidae, but It doesnt quite look like it.
Its obviously a lepidoptera but I'm not sure what family this butterfly could be.
This is a "Painted Lady" butterfly, which belongs to the family Nymphalidae, and the species Vanessa cardui.
The following is a distribution map of the butterfly within the US, and then Colorado specifically.
An interactive version of this map can be found here.
Following its annual spring migration the painted lady may be found anywhere in the state. However, it is primarily a species of fields and open areas. They are also common visitors to flowers in yards and gardens. The painted lady is one species that many school children have encountered as rearing one of these is now almost a rite of passage in elementary school classes. It is also the butterfly species commonly used for release at weddings and other celebratory events. source
This in mind, the painted lady is in no risk of being endangered.
The following is multiple choice question (with options) to answer.
More butterflies will come as buttercups become more | [
"advertised",
"ripe",
"social media friendly",
"toxic"
] | B | as the amount of fragrance of a flower increases , the number of pollinators it will attract increases |
OpenBookQA | OpenBookQA-4421 | electromagnetism, electricity
Explain the forces that will develop to both objects. There would be both magnetic and electric forces between the spheres. The electric forces would be repulsive, with magnitude $|\vec{F}_\text{elec}| = q^2/4 \pi \epsilon_0 r^2$, where $r$ is the distance separating them.
The magnetic forces can be found by noting that the dipole moment $m$ of each sphere will be given by the classical gyromagnetic ratio:
$$
m = \frac{q}{2m} L = \frac{q}{5} R^2 \omega,
$$
assuming the spheres have uniform charge density and uniform mass density. (In this case, $L = I \omega = \frac{2}{5} m R^2 \omega$, where $R$ is the radius of the spheres.)
Whether this creates an attractive or repulsive force depends on the relative orientation of the rotation axes and the line connecting the bodies. If we assume the axes of rotation are at right angles to the line connecting the spheres, then the magnetic force between them will be attractive and have magnitude
$$
F_\text{mag} = \frac{3 \mu_0 m^2}{4 \pi r^4} = \frac{3 \mu_0 q^2 R^4 \omega^2}{100 \pi r^4. }
$$
However, as noted by John Rennie in the comments, the magnetic forces will be much smaller than the electric forces. Specifically, we have
$$
\frac{F_\text{mag}}{F_\text{elec}} = \frac{3 \mu_0 \epsilon_0 R^2 \omega^2}{25} \frac{R^2}{r^2} = \frac{3 v^2}{25 c^2} \frac{R^2}{r^2},
$$
The following is multiple choice question (with options) to answer.
Which two objects are likely to be magnetic? | [
"a cell phone and a coffee mug",
"a credit card and the register",
"a cat and a dog",
"a tree and a power line"
] | B | magnetism does not require contact between objects to act |
OpenBookQA | OpenBookQA-4422 | physical-chemistry, inorganic-chemistry, everyday-chemistry, thermodynamics
Title: Strange observation! Every one have observed that when we pour cool water into a transparent glass (or simply glass), some droplets accumulate on the outside part. Did the droplets come pass through the glass? If they didn't, why is there accumulation of water droplets outside the glass? This is happening because of moisture present in air.
When you'll pour the cold water in a glass, the outer surface will also show fall in its temperature.
As you know already know that the heat flows from one body to another body until the temperature of both becomes equal.
So in our case the outer surface of the glass will absorb heat from surrounding, thereby causing in condensation of water present in air as moisture.
Another thing, you might notice that when you take out the bottle of cold water from a refrigerator, it have no droplets present on its outer surface because air inside the refrigerator is dry. But after when you place the same bottle out for a few minutes, you will observe the droplets on the outer surface of bottle.
You can also try to perform your experiment again by pouring normal water (at room temperature) in a glass and then placing it in refrigerator and then take it out after 30-40 minutes. Observe that if there are droplets present on the glass just after you take it out.
See this.
The following is multiple choice question (with options) to answer.
A warm glass place in the fridge will | [
"glow",
"condensate",
"shrink",
"crack"
] | B | water vapor cooling causes that water vapor to condense |
OpenBookQA | OpenBookQA-4423 | thermodynamics, fluid-dynamics, pressure, water, climate-science
Title: Would pumping warm humid air through a pipeline up to the top of a mountain produce a lot of fresh water? I have been doing a lot of research on the Internet lately about desalination processes and desalination plants and this led me to studying mountain weather and the orographic effect or orographic lifting.
The thought then occurred to me about whether a lot of fresh water could be produced by creating an artificially-produced orographic effect by pumping warm, humid coastal air through a pipeline that would lead to the top of a coastal mountain.
Orographic Effect:
I then made a conceptual drawing in MS Paint on how this could be done:
The temperature of the metal pipe will decrease as it ascends up the coastal mountain and this colder metal should cause the water vapor within the pumped air to condense on the inner wall of the pipeline forming water droplets. These water droplets will then be pulled down by gravity and should fall into a pipe leading to a water storage tank.
In the case that one air pumping plant cannot produce enough air pressure to push the air all the way up a mountain, then perhaps another air pumping plant would need to be stationed at the top of the mountain to assist with transporting the air upwards through the pipeline.
These air pumping plants would need to have a large volume industrial centrifugal blower fan like the ones built by Elektror Airsystems pictured here:
The following is multiple choice question (with options) to answer.
Which is likely to catch airborne water vapor on its sides? | [
"jail cells",
"sunlight",
"a hot drink",
"a cold drink"
] | D | water vapor cooling causes that water vapor to condense |
OpenBookQA | OpenBookQA-4424 | friction
Title: How to stop a leg from sliding? One of the legs of a bed is bent (I believe it buckled). The bent can be corrected to be straight, however under the application of load to the bed, the leg will slowly return to the bent position. My goal is to fix the leg in place and stop it from sliding.
My current idea is to increase friction between the bed leg and floor. As a first pass, I tried putting an old rubber slipper underneath the bent leg after correcting it(best I could come up with). It seemed to help a bit, but on heavier load (eg: a person getting on and off), the bending happens again.
I believe the material of the bed leg is some sort of plastic, and that of the floor is granite. Here are a few possible solutions you can try to stop the leg from sliding:
Furniture Grippers: You can buy furniture grippers, which are small pads that go underneath the legs of furniture to provide more friction and prevent sliding. These are available in many different sizes and shapes, and can be easily attached to the bottom of the bed leg. Look for grippers that are specifically designed for use on hard floors like granite.
Rubber Pads: Another option is to use rubber pads or discs underneath the bed leg. These can also be purchased at most hardware stores or online. The rubber material will help provide more grip and prevent sliding.
Anti-Slip Tape: Anti-slip tape is another option that can be used to increase friction between the bed leg and the floor. This tape has a rough surface that provides more traction, and can be easily cut to size and applied to the bottom of the bed leg.
Glue or Adhesive: If none of the above solutions work, you can try using a strong adhesive or glue to attach the bed leg to the floor. This should be a last resort, as it may damage the floor if you ever need to remove the bed in the future. Use a strong adhesive that is designed for use on plastic and granite surfaces.
Before trying any of these solutions, make sure the bed leg is straightened as much as possible to prevent any further bending. Good luck!
The following is multiple choice question (with options) to answer.
I would have a harder time sliding with my socks on | [
"marble floors",
"a shag runner",
"wood floors",
"ice"
] | B | friction acts to counter the motion of two objects when their surfaces are touching |
OpenBookQA | OpenBookQA-4425 | newtonian-mechanics, forces, kinematics, friction
Title: Why Do Objects move? Let's imagine a block resting on horizontal table. When We apply a force which is greater than frictional force it moves.
But why does this happen? Why can't friction withstand any force? As we know that one cause of friction is due to interlocking of irregularities, I think there is a opposing force as irregularities apply a normal force .
So why if applied force is increased the normal force can't withstand the increased force? Also is there any possibility that in a situation the frictional force could always cancel the applied force? Your image shows what is going on at the microscopic level between two surfaces. To understand why friction works, you have to look smaller, at the atomic level: and when you get to that point you're no longer taking about "friction" as we know it, but about physiochemical interactions between atoms and molecules. Those interactions are mediated by electromagnetic force and tend to be quite weak at the boundaries between two solid objects. As one example demonstrating the fundamentally chemical nature of the interactions, note that the reason it's easier to grip paper if your fingers are slightly damp is because the polar water molecules form bonds between your skin, the paper and each other, somewhat "gluing" everything together.
The following is multiple choice question (with options) to answer.
friction acts to counter the motion of two objects when their surfaces are what? | [
"converging",
"separated",
"in vision",
"apart"
] | A | friction acts to counter the motion of two objects when their surfaces are touching |
OpenBookQA | OpenBookQA-4426 | ecology, behaviour, sociality, predation, community-ecology
Title: How selective are wolves about the size of their prey? For an animal that lives and hunts socially like a wolf, is there a lower threshold to the size of prey items they will hunt? A pack wouldn't have much trouble with catching say a rabbit, but would the food provided be enough to actually make the hunt worthwhile? What is the limit in which a prey item becomes too small to be worth catching? You should not post here until you've demonstrated your own research effort. Given this stipulation -- and the rich literature about this very topic -- I will keep my answer cursory so as to act as starting points for your search. A simple Google or google Scholar search on your part will reveal many more details/studies.
You should review the following ecological concepts: prey switching, optimal foraging theory, principle of allocation, and others.
Some accessible articles on Prey-to-predator-size ratio include: Henriques et al. 2021, Tsai et al 2016, Cohen et al 1993, and Vézina 1985
Regarding wolves:
According to Becker et al 2018:
[Wolf] Prey selection is influenced by the absolute and relative abundances of prey types, the life history characteristics of predators and prey, and the attributes of the environment in which these interactions occur.
Smith et al. 2010 demonstrate that diets vary with season -- their focus being on winter diets.
Huggard 1993 shows the impact of environmental variables such as snow.
Herd density plays a significant role:
Sand et al. 2016
Davis et al 2012 showed that lower density of secondary prey mattered more than heightened density of primary prey.
Huggard 1993 (Canadian Journal of Zoology) showed that density of herds (vs herd density) mattered more in Banff National Park in Canada. Herd size and habitat also mattered -- with wolves avoiding some habitats and seemingly choosing places that optimized preferred habitats and large herd size.
Wolf scat/diet studies showing smallest species in their diet:
Sin et al 2019: smallest for Sandanavian wolves = domestic dogs
Nowak et al 2011 showed the following small prey made up the stated percentages of wolve's diets in Poland:
brown hare Lepus europeus (2.5%) and Eurasian beaver Castor fiber (1.4%). Domestic animals, exclusively dogs and cats, made up 1.0% of food biomass.
Works cited:
The following is multiple choice question (with options) to answer.
A wolf would eat | [
"an ibex",
"a mountain",
"a tree",
"a cloud"
] | A | predators eat prey |
OpenBookQA | OpenBookQA-4427 | zoology
Capybara, rabbits, hamsters and other related species do not have a complex ruminant digestive system. Instead they extract more nutrition from grass by giving their food a second pass through the gut. Soft fecal pellets of partially digested food are excreted and generally consumed immediately. Consuming these cecotropes is important for adequate nutritional intake of Vitamin B12. They also produce normal droppings, which are not eaten.
Young elephants, pandas, koalas, and hippos eat the feces of their mother to obtain the bacteria required to properly digest vegetation found on the savanna and in the jungle. When they are born, their intestines do not contain these bacteria (they are completely sterile). Without them, they would be unable to obtain any nutritional value from plants.
Eating garbage and human feces is thought to be one function of dogs during their early domestication, some 12,000 to 15,000 years ago. They served as our first waste management workers, helping to keep the areas around human settlements clean. A study of village dogs in Zimbabwe revealed that feces made up about 25% of the dogs’ overall diet, with human feces making up a large part of that percentage.
Coprophagia
Daily rhythms of food intake and feces reingestion in the degu, an herbivorous Chilean rodent: optimizing digestion through coprophagy
Coprophagia as seen in Thoroughbred Foals
The following is multiple choice question (with options) to answer.
Foxes eat | [
"wolves",
"mice",
"man",
"bears"
] | B | predators eat prey |
OpenBookQA | OpenBookQA-4428 | circuits, battery
Title: Looking for a device that breaks the circuit if the voltage gets too low I'm looking for a device that breaks a circuit once the voltage of my battery gets too low. This to protect the battery.
Example: I have a 12V battery, once it reaches ~11V the huge voltage drop begins, but the device that is connected to the battery still runs and draws current. I need another device that can detect the voltage goes below 11V and then automatically breaks the circuit, preventing the circuit to draw more current from the battery. Basically, it shuts down the whole circuit.
Since English is not my native language and I'm not aware of any kinds of systems in my own language, I'm having a hard time finding something like this. Thanks in advance.
EDIT: or can I make my own? The simple answer is that you can get off the shelf modules which does exactly what you want.
They are often called 'split charge modules' and are designed for installations like boats and motor-homes which have batteries charged off an engine alternator but prevent the starter battery form being fully discharged.
This is one example http://www.12voltplanet.co.uk/voltage-sensitive-relay-12v-140a.html
They are not expensive and are easy to fit with basic knowledge of electronic systems.
There are also more sophisticated systems which allow for conditioning and management of auxiliary batteries
I have used this brand before :
I can't remember the exact specification but they would certainly be in the 1A sort of range for a 12V system. I suggest this one in particular as it is easy to disassemble so you could discard the case and screw terminals to make it a lot more compact to package with the rest of your circuit.
The following is multiple choice question (with options) to answer.
What fails to work during a power outage? | [
"an electric fan",
"a hand pump",
"a campfire",
"a baseball bat"
] | A | electrical devices convert electricity into other forms of energy |
OpenBookQA | OpenBookQA-4429 | the-sun, space, stellar-atmospheres
However, when you have something the Sun or even fog, the optical depth varies with the distance you're looking into that object. I'll talk about fog since it's familiar, but the same idea applies to the Sun's atmosphere. Say you're standing in a forrest and its very foggy out. There's a tree 1 meter away from you that you can see. You could measure your optical depth, $\tau$, of the fog between you and tree and might find that $\tau = 0.15$. Since $\tau$ is less than one, that implies you can see the tree, but the value of $\tau$ also implies how well you can see it. If $\tau = 0$, there's nothing between you and the tree to impede your ability to see it. Let's say there's another tree that's 5 meters away. Now there's more fog between you and the tree and while you can still see it, it is harder to see it. The optical depth of the fog between you and the tree 5 meters away might be $\tau = 0.75$. It's still less than one, implying the tree is visible, but because there's more fog between you and the tree, the optical depth is higher. Finally, there may be a tree 10 meters away with so much fog between you and the tree that the optical depth is $\tau = 1.5$. You can't see this tree because there's too much fog in the way. Hopefully you now realize that anything which is at a distance where $\tau > 1$ is not visible to you. That effectively defines a "surface" around you precisely when $\tau = 1$. Anything beyond that point is not visible and anything closer is visible.
If you're talking about the Sun, you can look at the Sun, but you'll only see light which originates from a point where $\tau < 1$. There are countless photons bouncing around inside the Sun, but you can't see them because they're in an opaque part of the Sun. Astronomers use the optical depth as a metric for defining the "surface" of the Sun.
The following is multiple choice question (with options) to answer.
It's easier to spot something small twenty feet away on a cloudless day if | [
"the object is buried an inch underground",
"the object is a dirty black object on black ground",
"the object is a polished metal ring",
"the object is a dull green marble lying in live grass"
] | C | if an object reflects more light then that object is more easily seen |
OpenBookQA | OpenBookQA-4430 | atmosphere, carbon-cycle
Title: For a tree over its entire existence, does it actually have a net negative effect on atmospheric CO2? A tree while alive converts CO2 + water -> carbohydrates + O2. However, once the tree dies, it decays, releasing CO2 back into the atmosphere. My question is, over an individual tree's overall existence, does a tree actually contribute to a reduction in atmospheric CO2?
I'm aware there's other pathways a tree could end up as a more long term carbon store (carbonaceous rocks), but mostly interested in if a tree were to die and fall in a forest, decay in 50-150 years, would it have contributed to a net reduction in CO2, or does a tree typically act as more of a temporary 100+ year store of CO2? A brief review of recent non-paywalled available literature indicates that such an effect likely exists but that it is difficult to quantify based on currently available data.
Some amount of carbon from trees can be sequestered in the soil for periods time significantly longer than the typical above-ground decomposition time of organic matter, potentially for millennia. This clearly lengthens the carbon cycle time, but it is not clear to me whether this represents carbon storage, as there does not seem to be a well established minimum cut-off time for this. The primary source for soil-sequestered carbon are tree roots, with leaf litter constituting a secondary source.
The following paper (preprint online) addresses the question in the specific context of agroforestry, i.e. cropland interspersed with trees. The paper notes multiple times that the processes involved in soil sequestration are not well understood and that quantitative measurements and estimates vary widely, as one would expect based on differences in climatic and soil condition. Note on units: A Mg corresponds to a metric ton.
Klaus Lorenz and Rattan Lala, "Soil organic carbon sequestration in agroforestry systems. A review." Agronomy for Sustainable Development, Vol. 34, No. 2, April 2014, pp. 443-454.
The following is multiple choice question (with options) to answer.
A decrease in trees may be attributed to | [
"dendrophilia",
"hiking enthusiasts",
"increased chainsaw sales",
"nature photographers"
] | C | cutting down trees in a forest causes the number of trees to decrease in that forest |
OpenBookQA | OpenBookQA-4431 | biochemistry, microbiology, microbiome
„the higher the potential, the higher the dissolved oxygen in medium“.
I think the wording is misleading, since high redox potential is a consequence of oxygen being present, not the other way around (as that would imply something like high redox potential attracting atmospheric oxygen into water). I speculate that the author meant that dissolved (organic) compounds tend to release $O_2$ (or rather any reactive oxygen species (ROS)) more often in an oxidative milieu.
The following is multiple choice question (with options) to answer.
If soil is loose, it makes it what for oxygen to get in? | [
"seven",
"boring",
"harder",
"simpler"
] | D | the looseness of soil increases the amount of oxygen in that soil |
OpenBookQA | OpenBookQA-4432 | soil
An analogous hypothesis proposed by RUSSEL3 for increases in the number of bacteria after partial sterilization by heat, frost, or other means is that by such partial sterilization the protozoa are killed, thus permitting the unhindered development of bacteria which under normal conditions is held in check by protozoa.
BROWN and SMITH (loc. cit.) in their investigations dealt mainly with the physiological activities of bacteria under conditions of low temperature and frost, although they also made some determinations of the number of bacteria in frozen soil. Their principal conclusions regarding the ammonifying, nitrifying, denitrifying, and nitrogen fixing powers of frozen soils are as follows: (1) that "frozen soils possess a much greater ammonifying power than unfrozen soils"; (2) that "during the fall season, the ammonifying power of the soil increases until the temperature of the soil almost reaches zero, when a decrease occurs, and this is followed by a gradual increase and the ammonifying power of the soil reaches a maximum at the end of the frozen period"; (3) that "the nitrifying power of frozen soils is weak and shows no tendency to increase with extension of the frozen period"; (4) that "frozen soils possess a decided denitrifying power which seems to diminish with the continuance of the frozen period"; (5) that "during the fall season, the denitrifying power of the soil increases until the soil freezes, after which a decrease occurs"; (6) that "frozen soils possess a nitrogen fixing power which increases with the continuance of the frozen period, being independent of moderate changes in the moisture conditions, but restricted by large decreases in moisture"; and (7) that "in the fall, the nitrogen fixing power of the soil increases until the soil becomes frozen, which in almost ceases, after which a smaller nitrogen fixing power is established."
The following is multiple choice question (with options) to answer.
The looseness of soil increases the amount of what in it? | [
"bugs",
"dirt",
"water",
"air"
] | D | the looseness of soil increases the amount of oxygen in that soil |
OpenBookQA | OpenBookQA-4433 | biochemistry, medicinal-chemistry
Title: What makes a metal safe to use for an artificial joint? What determines if a metal is suitable for transplantation such as in the hip? What I am most interested in however is why might some metals be toxic to animals once in the body? There are a number of reasons why a given metal may be toxic to an animal:
Radioactive metals are the easy ones.
Some metals can affect the normal biosynthetic pathways within the body. Lead is a good example of this, as it can take the place of calcium; I believe beryllium does the same for magnesium.
Some metals themselves are very reactive. Hexavalent chromium ($Cr(VI)$) is highly reactive, and will cause damage through severe oxidative reactions, whereas $Cr(III)$ is largely okay.
A lot of metals are okay, even required, at some level, but become toxic at too high a concentration. Iron, for example.
People can simply have allergies to metals. Nickel in silver jewelry is a good example, although in my experience it can be overcome.
The basic gist is that some metals are required for life, some aren't but aren't too terrible, and some are completely toxic to it. Different organisms can vary a bit in which metals are useful or not. A good implant will of course not be toxic at all, and will be strong and long-lasting. Titanium is often used, given its strength and general nonreactiveness, but so is cobalt, despite being toxic to some degree.
Ref: Metal Sensitivity in Patients with Orthopaedic Implants. Hallab, et al. J Bone Joint Surg Am, 2001 Mar 01;83(3):428-428
The following is multiple choice question (with options) to answer.
Something that could cause harm to an animal could be | [
"affection",
"hugs",
"love",
"punches"
] | D | humans changing animal habitats usually causes harm to those animals |
OpenBookQA | OpenBookQA-4434 | species-identification, zoology, entomology
Title: Species identification; clusters of big plump red bugs in Taipei I saw these red insects in Taipei near XinBeitou MRT station in the last week of April 2017, around lunch time. They were fairly active and would keep checking each other out with their antennae for a moment and then move on to the next. What struck me was the wide range of sizes and development in the groups. I didn't notice any feeding or mating that I could recognize, just a lot of walking around and checking each other out.
There are plenty of birds around (this is quite a green area) but I didn't notice any interest by birds in eating them.
I've also included a screenshot from google maps so you can see the location and the trees growing in these concrete structures.
The body of the largest individual is probably 2.5 centimeters long. I'm fairly certain these true bugs belong to the species Leptocoris vicinus, and carry the nickname of "soapberry bugs", which is specific to the subfamily Serinethinae. They're quite common in urban areas of Southeast Asia, which coincides nicely with where you encountered them.
Also, you had mentioned,
There are plenty of birds around (this is quite a green area) but I didn't notice any interest by birds in eating them.
Soapberry bugs, as well as many other types of insects, are able to freely congregate in large numbers, and in such exposed places, due to their bright coloration. Having such a bright color may indicate to some predators that the prey in consideration is toxic, a phenomenon referred to as aposematism.
source
source
And then, here's a map of their distribution, with Taipei holding marker #37. (source)
An interactive version of this map can be found here.
The following is multiple choice question (with options) to answer.
Which is likeliest to harm the snowy owl population in an area? | [
"a new mall",
"a new puddle",
"a new tree",
"a new preserve"
] | A | humans changing animal habitats usually causes harm to those animals |
OpenBookQA | OpenBookQA-4435 | evolution, botany, development, fruit, seeds
What is the point of fruit if not to be eaten? It’s my understanding that organisms will adapt to survive and thrive. I understand that being eaten can spread seeds, but this just seems like too much of a risky tactic to rely on.
Following on from part one: If being eaten is the best way to spread seed, why do some plants avoid this (such as by being poisonous or thorny)? Seeds are spread by many mechanisms
Wind dispersal: When air currents used to spread seeds. Often these plants have evolved features to facilitate wind catching, for example dandelions. Aka, anemochory.
Propulsion & bursting: When seeds are propelled from the plant in an such as in these videos. This is called Ballochory.
Water: Similarly to wind dispersal plants can spread seeds by water movement/currents, aka Hydrochory. This is used by many algae and water living plants.
Sticky Seeds: There are many ways a seed can attach to the outside of an animal - by using hooks, barbs, sticky excretions, hairs. Seeds then get carried by an animal and fall off later. This is epizoochory.
Fruiting: Plants can use seed-bearing fruit to encourage animals to eat the seeds. They will then be spread when the waste is excreted after digestion. This is a process of endozoochory.
More than one way to spread a seed
The following is multiple choice question (with options) to answer.
This seed carries food: | [
"rock",
"strawberry",
"thunder",
"water"
] | B | a seed is used for storing food for a new plant |
OpenBookQA | OpenBookQA-4436 | meteorology, climate-change, gas, pollution
If you are interested in Greenhouse Gases (e.g. methane, carbon dioxide, CFCs, nitrous oxide), the EPA has a separate site for those emissions since they are not part of the same regulatory framework http://www.epa.gov/climatechange/ghgemissions/ . Greenhouse gases typically do not cause adverse health effects for plants or animals on land. However, they have long-term radiative effects (e.g. the greenhouse effect) because they stay in the atmosphere for many years and trap infrared light. These long-term radiative effects are what can change climate and consequently land cover. Furthermore, most of the excess carbon is absorbed by the ocean, which creates carbonic acid. Increased acidity of the ocean causes severe problems for marine ecosystems.
The EPA states that in 2012 the CO2 equivalent GHG emissions for the USA by sector was:
The following is multiple choice question (with options) to answer.
What have a negative impact on the environment? | [
"plants",
"recycling plants",
"dumpyards",
"oceans"
] | C | landfills have a negative impact on the environment |
OpenBookQA | OpenBookQA-4437 | wildfire
There are detailed satellite imagery with PM2.5 monitor overlay at Aerosol Watch, if you would like to see how the event progressed through time.
The following is multiple choice question (with options) to answer.
A bad spot in town, as far as nature and the health of Earth is concerned, will be | [
"heaped refuse",
"piled compost",
"pollinated flowers",
"watered gardens"
] | A | landfills have a negative impact on the environment |
OpenBookQA | OpenBookQA-4438 | thermodynamics, atoms, phase-transition
But let's look at how the states change. In a solid, you have a bunch of atoms that can be thought of as masses connected by springs. As heat is added to the system, the atoms begin to vibrate in the lattice of springs. As more heat is added, they vibrate enough to break the springs. This is when the solid begins to melt and turn to a liquid.
Now you have a liquid where the atoms are all moving around but they aren't free to move wherever they want. More heat is added to the system and the atoms begin to translate faster and faster. Eventually they translate fast enough to overcome the forces that are holding them together in a liquid. Now they fly free and are a gas.
So ultimately, heat is energy that makes atoms and molecules move in some way. They may translate, rotate, vibrate, or the electrons may begin moving around depending on how much heat is there and what configuration the molecule has.
The following is multiple choice question (with options) to answer.
if an object undergoes chemical change then that object will have new chemical what? | [
"warmth",
"temperature",
"appearance",
"attributes"
] | D | if an object undergoes chemical change then that object will have new chemical properties |
OpenBookQA | OpenBookQA-4439 | ros, sicklms
Originally posted by Stefan Kohlbrecher with karma: 24361 on 2014-05-15
This answer was ACCEPTED on the original site
Post score: 0
Original comments
Comment by Ashesh Goswami on 2014-05-17:
thanks a lot..yes I agree that the Velodyne 3D LIDARS are the main sensors used for complex autonomous car projects but it is a very expensive tool to be used in case I am planning to perform comparatively easier tasks like lane change or collision avoidance..so I guess I should keep the hunt on to see if any radar related help is available..otherwise I would stick to the SICK LMS laser-scanner.
The following is multiple choice question (with options) to answer.
Laser anemometers help manufacturers of cars, airplanes and spacecraft to produce efficient vehicle designs that | [
"increase the gas mileage of the vehicles",
"increase the drag from air moving past them",
"decrease exhaust fumes from the vehicles",
"reduce resistance from air moving past them"
] | D | an anemometer is used to measure wind speed |
OpenBookQA | OpenBookQA-4440 | You are in the case $P=true$ and $Q=true$, so $(not(P) \Rightarrow not(Q))=true$.
The following is multiple choice question (with options) to answer.
Which is true | [
"an anemometer would measure a tropic front",
"an anemometer would measure thunder",
"an anemometer would measure a rainbow",
"an anemometer would measure a lightning bolt"
] | A | an anemometer is used to measure wind speed |
OpenBookQA | OpenBookQA-4441 | meteorology, weather-forecasting
Title: Some website or institute with integrated statistics on forecasting the occurrence of rainbows I am a lay person in meteorology, maybe this is not the right place for my question, but I would like to ask then.
My question is simple: is there a website or institute that has integrated statistics on forecasting the occurrence of rainbows in different countries around the world? A rainbow is not a physical object that has a position. It is an optical phenomena that depends on your location relative to the sun and rain. If you are standing where your eyes can intercept the colored light, you are standing with your back to the sun and the sunlight is reflecting on raindrops in front of you. Someone else standing in a different location would not necessarily see a rainbow if they looked up at the same part of the sky.
From University of Illinois:
According to Descartes' calculations using laws of optics, the three stage refraction-reflection-refraction pattern that light undergoes when passing through a raindrop produces a concentration of outgoing rays along a line that is 42 degrees above the head of an observer's shadow. This concentration of light rays is the rainbow that we see.
Also this National Geographic article has a nice description:
Viewers on the ground can only see the light reflected by raindrops above the horizon. Because each person's horizon is a little different, no one actually sees a full rainbow from the ground. In fact, no one sees the same rainbow—each person has a different antisolar point, each person has a different horizon. Someone who appears below or near the "end" of a rainbow to one viewer will see another rainbow, extending from his or her own horizon.
What this means is that a rainbow is not really a meteorological occurrence that can be measured or catalogued, because you would get a different answer depending on your reference point. Lightning, in contrast, is a physical phenomena that has a precise location which can be determined and verified from multiple points of reference.
Rainbows are photographed and archived by enthusiasts, but it's really about artistic appreciation. While I have not looked into rainbow forecast services, a quick search shows some interesting resources, such as How to Predict Rainbows and Plan Photographs which has a link to a photography app that can plan for rainbows and here is a rainbow app you can install on your phone.
How Rainbows Happen also has a nice description (shown below) and some other useful resources.
The following is multiple choice question (with options) to answer.
What time are you most likely to see a rainbow | [
"10:00 A.M.",
"9:00 P.M.",
"3 A.M.",
"Midnight"
] | A | sunlight and rain can cause a rainbow |
OpenBookQA | OpenBookQA-4442 | human-biology, hair
As for Northern Europeans, blond hair and white skin are actually one of those traits where it's hard to separate random variation from natural selection. It is quite likely there are advantages to being fair in high latitudes where there is little sunlight; you need less protection from the sun in the first place, and you need to be able to get enough vitamin D from sunlight on the other. However this applies much more obviously to skin than to hair. Blond hair is the result of very few mutations, which are thought to have appeared around 11,000 years ago. So it could be that those mutations happened to occur and to spread through those populations and not others and that's why they're blond and most other human populations (Melanesians excepted) are not. Or it could be that once those mutations happened they spread particularly well in those populations because it was adaptive in their environment. The question isn't scientifically settled.
https://en.wikipedia.org/wiki/Blond#Evolution_of_blond_hair
The following is multiple choice question (with options) to answer.
Why might a polar bear grow white hair? | [
"blend in",
"stand out",
"random",
"look fancy"
] | A | the arctic environment is cold in temperature from being at a northern lattitude below 0 degrees celsius during most of the year |
OpenBookQA | OpenBookQA-4443 | the-moon, night-sky
And another useful reference at planetarium.madison.k12.wi.us:
At the beginning of Winter, when it's nighttime all of the time, the moon would be in the sky for the 2 weeks closest to Full Moon, and then below the horizon for the next 2 weeks. And at the beginning of Spring (click on the graphic), when the sun is at sunrise all of the time, the moon would be up in the sky for the 2 weeks closest to First Quarter (waxing), and then below the horizon for the next 2 weeks.
The animated graphic above shows what we would see from the North Pole if we went out every day at noon, for 14 days in a row, from March 1st to March 14, 2006. We start with a thin crescent moon near the horizon, and end with a full moon near the horizon. Halfway through, the First Quarter moon would be when the moon is highest above the horizon.
Keep in mind, that if you were observing the moon constantly, throughout a 24 hour period, the moon would seem to move to the right in the sky along with the sun, stars, and planets due to the Earth's rotation. Nothing would seem to rise and set: they would just seem to circle around you.
The following is multiple choice question (with options) to answer.
As the earth glides from winter into spring you will witness | [
"leaves growing",
"blizzards",
"bears starting hibernation",
"leaves turning orange"
] | A | temperature changing can cause phase changes |
OpenBookQA | OpenBookQA-4444 | evaporation
Title: How much does lighting of room effect evaporation? Suppose there is a wet floor under normal conditions, how much can we alter the rate of evaporation of the wet floor by trying out different types of lights ex. Incandascnet, cfl, fluorescent etc ? I assume that these lighting solutions produce all types of EM waves but they must have distributed it unsymmetrically over the spectrum, now waterhas the frequency that equals that of microwave so my first guess was that turning on the light which emits maximum microwave would produce the fastest results. But then incandescent bulb produces lots oh heat which can heat up the water and then make it evaporate, how to compare and what would be the best solution ? I strongly suspect that the choice of bulb will make no noticeable difference in evaporation rate. The total energy density striking the floor due to a 100 W bulb, even assuming that all of the energy is converted to light, is on the order of 120 $\mu \mbox{W}/\mbox{cm}^2$, which is tiny, and real bulbs are only on the order of 1% to 5% efficient, with most of the rest of the energy carried away as heat via convective cooling of the lamp surface by air. So, it's probably more like at most 20 $\mu \mbox{W}/\mbox{cm}^2$, and in either case, this is a tiny power density.
In contrast, you need power densities on the order of 10,000 $\mu \mbox{W}/\mbox{cm}^2$ to be able to see radiation make a noticeable color change on thermal-sensitive liquid crystal sheets, and those are thin, unlike the floor, which is thick and thus can also dissipate heat via conductive cooling. So the radiation due to a single light bulb is unlikely to have any impact on the heating and subsequent evaporation of water on a wet floor.
The following is multiple choice question (with options) to answer.
Which of the following actions can make electrical energy brighten your room? | [
"Clap on!",
"Jumping in place",
"Turning a doorknob",
"Rubbing your nose"
] | A | a light bulb converts electrical energy into light energy when it is turned on |
OpenBookQA | OpenBookQA-4445 | electromagnetism, energy, electric-current
Title: Where does the energy of the electric cable come from? I'm stuck on one really simple example, I can't figure out what's happening to energy here...
(This is not homework)
Let's consider an uncharged electric cable, we'll model it by an infinite cylinder on the axis $(Oz)$ with radius $a$ and conductivity $\gamma$ with uniform, constant current $I$, and we'll obviously use cylindrical coordinates $(\vec{e_r},\vec{e_\theta},\vec{e_z})$.
If I haven't made any mistake, we should have the electric and magnetic fields $\vec{E},\vec{B}$ as follows :
$\vec{E}=\begin{cases}\frac{1}{\gamma}\frac{I}{\pi a^2}\vec{e_z}&r<a\\\vec{0}& r>a\end{cases}$,
$\vec{B}=\begin{cases}\frac{\mu_0I}{2\pi}\frac{r}{a^2}\vec{e_\theta}&r\le a\\\frac{\mu_0I}{2\pi}\frac{1}{r}\vec{e_\theta}&r\ge a\end{cases}$
Thus the poynting vector $\vec{\Pi}=\begin{cases}\frac{-r}{2\pi^2\gamma a^4}I^2\vec{e_r}&r< a\\\vec{0}&r> a\end{cases}$
The following is multiple choice question (with options) to answer.
Which is an electrical energy conductor? | [
"cobalt",
"plastic",
"concrete",
"mahogany"
] | A | metal is an electrical energy conductor |
OpenBookQA | OpenBookQA-4446 | electromagnetism, computer
As for MRI scanners, there's a reason why the first and last thing they check, when you go and have an MRI scan, is that you have nothing potentially ferromagnetic on or in your body. The reason is that anything ferromagnetic that gets too close to an active MRI magnet is likely the get torn off your hands and violently slammed against the magnet. This has been known to happen to pretty much any wholly or partially ferromagnetic object you'd care to imagine, from wheelchairs, office chairs and floor polishers to scissors, oxygen bottles (which killed a small child) and even pistols (which, yes, went off when it hit the scanner).
So, let's imagine what'll happen to your hapless policeman, as he's walking towards the magnetized door carrying a stack of hard drives. The first thing he's likely to notice, while still several meters away, is that something's pulling at the drives he's carrying (since they have a lot of ferromagnetic metal in the casing, and even some pretty strong magnets inside). If he's not careful, the drives might slip out of his hands and fly through the air towards the door, slamming against the door jamb with enormous force (and, yes, likely getting pretty well wiped in the process).
The next thing he might notice, if that's not enough to make him stay well away from the door, is that the same force is also tugging at his badge, gun, zipper, belt buckle, the screwdriver in his pocket that he used to open the servers and extract the hard drives, and anything else metallic that he might have on him. If he's not careful, and keeps approaching the door, those items might either get pulled out of his pockets, or they might simply get drawn to the door and pull him along with them. If he's lucky, the only thing getting pinched between the door and the objects is his clothing. If he's not...
The following is multiple choice question (with options) to answer.
This object in your pocket is the most likely to shock you | [
"your phone",
"your credit card",
"your library card",
"your wallet"
] | A | metal is an electrical energy conductor |
OpenBookQA | OpenBookQA-4447 | everyday-life
Due to friction effects though, option c is still best. Pedaling hard will quickly deplete energy reserves while pedaling at a slow but steady rate will allow you to cycle for much longer. From a physics point of view, we cannot help you spend less energy, it will inevitable take about the same amount of energy regardless of your method (some +/- due to friction, etc). But by keeping your power usage low, you can go much farther before needing a rest. It is much the same as with running and walking. Simplistic physics says both use the same amount of energy, but you won't get as far by running due to the massive power requirements.
The following is multiple choice question (with options) to answer.
If I wanted to build endurance I could | [
"cycling to Publix",
"eat more food",
"sleep all day",
"only eat pizza"
] | A | exercise has a positive impact on a body 's strength |
OpenBookQA | OpenBookQA-4448 | physical-chemistry, everyday-chemistry, thermodynamics
As a comparison to this example, let's check out two liquids that do mix.
3. Water and ethanol
For the water, we have basically the same situation as before -- water molecules forming good bonds to each other. The ethanol, though, has an -OH group that can form bonds to the water in the same way that the water does (though not as well). This means that ethanol that mixes with water (and vice versa) will tend to stay mixed, and given that the liquids are being mixed around just by random motions, means that you'll get one mixing with the other just as a matter of statistics.
The following is multiple choice question (with options) to answer.
An example of combining two substances is | [
"pouring queso into guacamole",
"setting a laptop on a desk",
"building a roof on a house",
"putting clothes in a suitcase"
] | A | An example of combining two substances is pouring one substance into the other substance |
OpenBookQA | OpenBookQA-4449 | botany, plant-physiology, plant-anatomy
It made me wonder if we are simulating the sun in a dark room for growing the plants with the help of red, blue, and a little bit of far-red light, what will happen to the plants if we keep the ideal conditions for which the plants carry out photosynthesis whole day? Does it affect its yield or the plants die out quick?
I am an engineering student working on indoor farming, my knowledge of botany is the same as a high school student. So if I am wrong please tell me. Ideal conditions for photosynthesis
You mention ideal conditions to carry out photosynthesis, I would just like to point out that this includes carbondioxide levels, temperature, and nutrients as well as light.
Flowering
As anongoodnurse mentions performance might be measured by blooming which, in most flowering plants, has a day-light related component. However, for general growth increasing daylight over the 'natural' day length can often increase yield.
Daylight Cycles
The important point to note is that plants do 'ramp up' at dawn getting ready to start photosynthesizing (for some plants with temporal photosynthesis mechanisms (see CAM photosynthesis) this can be even more important). The reason plants do this is because plants can suffer from 'photobleaching' which can be considered similar to sunburn in humans, if they are not ready for sunlight. Getting 'ready' can involve lots of things including opening stomata (pores) to let CO2 in, changing which metabolic pathways are active, and moving about chloroplasts inside cells. Plants 'figure out' how and when to ramp up based on circadian rhythms which work well on 24 hour clocks and slight changes over time. Thus 12 hrs to 16 hrs can be a big change, particularly if the change happens by lights coming on earlier. Additionally, the 24 hour 'clock' means that plants will do better with 18hr light then 6hrs dark cycles than 36hrs light 6 hrs dark, because the total cycle length should be about 24hrs.
Photosynthesis Side Effects
The following is multiple choice question (with options) to answer.
A plant needing to photosynthesize will best be able to | [
"in a roofless room",
"in a cardboard box",
"in a windowless room",
"in a car with tinted windows"
] | A | a plant requires sunlight for photosynthesis |
OpenBookQA | OpenBookQA-4450 | newtonian-mechanics, energy, everyday-life, biophysics
Running involves more and varied movements, it's a very different gait. It is definitely not just the same movement as walking but faster. Some of those movements are vertical, or relate to jumping, some have shock absorption components and relate to landing. Much of that extra energy is dissipated both ways - we use energy both to jump and to cushion and come to a halt on landing. We also accelerate our feet to match our ground speed and must slow them to zero each stride, then speed and lift the other way as well, not just rely on gravity and pendulum activity. The fact this is at extension and not at ground impact doesn't change anything. Again, energy is lost both ways. I'm also going to guess that it's harder to be efficient across a wider compared to narrower range of motions, therefore the wider range of movements and systems used in running means it's much more likely that efficiency varies considerably, according to biological subsystem or type of movement.
Human gross muscle motion energy handling/metabolism is not efficient and doesn't behave like an ideal object. We have multiple energy pathways, and switch between them according to need. This happens less with walking, more with vigorous exercise like running. The "emergency" or "sustained activity" energy cycle our bodies switch to, when running, is less efficient - if it was more efficient it would probably have evolved as our primary not our fallback. And of course many biochemical reactions and body responses just aren't linear; they also may have min/max rates or durations.
The following is multiple choice question (with options) to answer.
If a being is moving regularly, then that being is | [
"hardly healthy",
"probably strong",
"about to die",
"making little motion"
] | B | exercise has a positive impact on a human 's health |
OpenBookQA | OpenBookQA-4451 | brain, exercise
Neuromodulators are involved in a variety of processes including pain
modulation, reward, response to stress, and autonomic control.
In humans, acute exercise causes significant increases in peripheral
levels of endogenous opioids; this effect is intensity-dependent,
corresponds to acute exercise-induced changes in HPA axis hormones,
and is linked to improvements in mood.
Though the endogenous opioids have received much attention in terms of
their involvement in the “runner’s high”, scientists are beginning to
understand that endocannabinoids may be equally or perhaps more
involved.
Other sources:
Effects of physical exercise on anxiety, depression...(Clinical Psychology Review, 2001):
Acutely, emotional effects of exercise remain confusing, both positive
and negative effects being reported.
...or as Alex Corb, PhD says in Boosting Your Serotonin Activity (Psychology Today):
Interestingly, if you try to do too much exercise, or feel forced into
doing it, it may not have the right effect. Recognizing that you are
choosing to exercise changes its neurochemical effect. That may be a
result of your ancient instincts — the difference between running
because you're hunting something, and running because it's hunting
you.
How to increase serotonin in the human brain without drugs (Journal of Psychiatry & Neuroscience, 2007):
Exercise improves mood in subclinical populations as well as in
patients. The most consistent effect is seen when regular exercisers
undertake aerobic exercise at a level with which they are familiar.
The following is multiple choice question (with options) to answer.
What kind of impact does exercise have on a humans health? | [
"terrible",
"low",
"skyrocketing",
"bad"
] | C | exercise has a positive impact on a human 's health |
OpenBookQA | OpenBookQA-4452 | evolution, botany, development, fruit, seeds
What is the point of fruit if not to be eaten? It’s my understanding that organisms will adapt to survive and thrive. I understand that being eaten can spread seeds, but this just seems like too much of a risky tactic to rely on.
Following on from part one: If being eaten is the best way to spread seed, why do some plants avoid this (such as by being poisonous or thorny)? Seeds are spread by many mechanisms
Wind dispersal: When air currents used to spread seeds. Often these plants have evolved features to facilitate wind catching, for example dandelions. Aka, anemochory.
Propulsion & bursting: When seeds are propelled from the plant in an such as in these videos. This is called Ballochory.
Water: Similarly to wind dispersal plants can spread seeds by water movement/currents, aka Hydrochory. This is used by many algae and water living plants.
Sticky Seeds: There are many ways a seed can attach to the outside of an animal - by using hooks, barbs, sticky excretions, hairs. Seeds then get carried by an animal and fall off later. This is epizoochory.
Fruiting: Plants can use seed-bearing fruit to encourage animals to eat the seeds. They will then be spread when the waste is excreted after digestion. This is a process of endozoochory.
More than one way to spread a seed
The following is multiple choice question (with options) to answer.
Animals help with seed dispersal due to the seeds from the fruit they eat being | [
"expelled via excrement",
"smiled",
"expelled from school",
"kicked"
] | A | An example of seed dispersal is is an animal gathering seeds |
OpenBookQA | OpenBookQA-4453 | botany, species-identification
Title: Plant identification? Can anyone identify the plant below? It's in a backyard in Pennsylvania, and the photo was taken today. Those flowers don't come from the same plant as that big leaf in the front do they? Cant help you with the leaves, but the flower looks like a daylily. source: I know nothing about plants, but happen to have a mom who got a degree in horticulture :)
The following is multiple choice question (with options) to answer.
f a plant shows up in a new place, what might have happened? | [
"the plant is able to relocate itself",
"it spontaneously appeared there",
"its cased embryo have been dispersed",
"it walked to the new place"
] | C | An example of seed dispersal is is an animal gathering seeds |
OpenBookQA | OpenBookQA-4454 | zoology
Capybara, rabbits, hamsters and other related species do not have a complex ruminant digestive system. Instead they extract more nutrition from grass by giving their food a second pass through the gut. Soft fecal pellets of partially digested food are excreted and generally consumed immediately. Consuming these cecotropes is important for adequate nutritional intake of Vitamin B12. They also produce normal droppings, which are not eaten.
Young elephants, pandas, koalas, and hippos eat the feces of their mother to obtain the bacteria required to properly digest vegetation found on the savanna and in the jungle. When they are born, their intestines do not contain these bacteria (they are completely sterile). Without them, they would be unable to obtain any nutritional value from plants.
Eating garbage and human feces is thought to be one function of dogs during their early domestication, some 12,000 to 15,000 years ago. They served as our first waste management workers, helping to keep the areas around human settlements clean. A study of village dogs in Zimbabwe revealed that feces made up about 25% of the dogs’ overall diet, with human feces making up a large part of that percentage.
Coprophagia
Daily rhythms of food intake and feces reingestion in the degu, an herbivorous Chilean rodent: optimizing digestion through coprophagy
Coprophagia as seen in Thoroughbred Foals
The following is multiple choice question (with options) to answer.
A creature that is a biped and which regularly uses tools will occasionally enjoy munching on | [
"kettle shards",
"old feces",
"chia seeds",
"hard rocks"
] | C | humans sometimes eat seeds |
OpenBookQA | OpenBookQA-4455 | human-biology, food
Title: Can humans eat grass? Can a human eat grass and digest it?
Could it be possible to use it as food just like other plants such as wheat or beans? To elaborate on A random zoologist's answer, the problem is that the human digestive system does not contain any cellulase enzymes. Cellulases are a class of enzymes that break down cellulose, the chief structural component of plants. You might be able to obtain a small amount of nutrition from grass or other cellulose-rich materials, but as the plant cell walls are made of cellulose, most of the plant material will be indigestible.
The following is multiple choice question (with options) to answer.
Humans sometimes eat what? | [
"air",
"kernels",
"ocean water",
"rocks"
] | B | humans sometimes eat seeds |
OpenBookQA | OpenBookQA-4456 | botany, plant-physiology
Title: Can any plant regenerate missing tissue? I have not yet found a plant that, when an insect eats a hole in one of its leaves, it can regenerate the lost tissue. Many plants will grow a new stem if the old one is cut, but it is not a perfect regeneration, and has no likeness in form to the previous stem. Are there any plants that can, even to a degree, regenerate missing tissue? In general, plant cells only undergo differentiation at special regions in the plant known as meristems. Two of the primary types of meristem are the root apical meristem (at the tips of roots) and the shoot apical meristem (at shoot tips)^. Within the shoot apical meristem the plant cells divide and begin to differentiate into different cell types (such as different cells of the leaf, or vascular cells). Later growth (of, say, a leaf) is largely a result of cell expansion (although cell division does still occur, but drops off as the leaf expands). Therefore, if you punch a hole in a leaf, it probably won't be filled in because the cells in that leaf have finished growing and dividing.
However, as a shoot grows, more meristems are created. These are found in the axillary buds, just above where the leaf meets the stem. The meristems in the axillary buds can grow to form branches. Different plants obviously make different numbers of branches, but there is a common control mechanism known as apical dominance, where the meristem at the tip of the shoot suppresses the growth of the lower axillary buds. This is why a shoot with no branches can be made to grow branches by cutting off the tip (gardeners often do this to make "leggy" plants more bushy).
All of that was a long explanation to say, no, a plant doesn't normally^^ regenerate in the sense of filling in cells that have gone missing. However, if you cut off a shoot, the next remaining bud might begin to grow and, in a sense, replace the part that was lost. In that case, an existing bud is recruited to form a new branch and replace lost functionality, but I wouldn't say that qualifies as regenerating missing tissue.
^There are other types of meristem as well.
The following is multiple choice question (with options) to answer.
specialized tissues at the ends of plant stems are used for growing taller by what? | [
"boots",
"people",
"animals",
"flora"
] | D | specialized tissues at the ends of plant stems are used for growing taller by plants |
OpenBookQA | OpenBookQA-4457 | botany, homework, terminology, plant-anatomy, tissue
Interfascicular cambium differentiates from parenchyma or collenchyma cells located between the vascular bundles (mainly in stem)
The following is multiple choice question (with options) to answer.
Which most likely requires the aid of specialized tissues at the ends of stems? | [
"human assisted space travel",
"the quick growth of bamboo",
"cats digging with their claws",
"the slow growth of mammals"
] | B | specialized tissues at the ends of plant stems are used for growing taller by plants |
OpenBookQA | OpenBookQA-4458 | genomics
In the case of a single gene with a single copy on both the maternal and paternal chromosomes, the Punnet Square accurately estimates the probably of inheriting each possible genotype. (50% chance of getting one of two alleles from dad * 50% chance of getting one of two alleles from mom). In the case of multiple genes on different chromosomes, the 50% chance of any given allele still holds, as all the genes segregate independently. The accuracy of the Punnet Square fails when genes are sufficiently close to each other on the same chromosome. Genes distant from each other on the same chromosome still segregrate independently due to a high level of recombination events between chromosomes in meiosis I, but genes in close physical proximity no longer segregate independently. The closer two genes are physically the more they tend to co-segregate. This tendency is reported empirically as a "distance" in centiMorgans and is related to physical distance in base pairs (kB or mB) but is not completely proportional to physical distance due to the existence of recombination "hot spots."
It's important to note that is accurately predicts genotypic ratios, but not necessarily phenotype. Phenotypes can be less than 100% penetrant, can cause embryonic lethal, epistasis, etc. Such that the observed phenotypic ratio does not match the predicted ratio. (For example, if YY was known to be 100% embryonic lethality, live births -> observed phenotypes instead be expected at 1/3 of each of the remaining genotypes. If Y was instead phenotypically dominant (one copy of Y determines phenotype), then 75% of children would be expected to be phenotypically Y (genotypically, the Y phenotypic children would be expected to distribute evenly between YO, YY, BY).
The following is multiple choice question (with options) to answer.
a Punnett square is used to identify the percent chance of a trait being passed down from a parent to its what? | [
"home",
"younglings",
"animals",
"pets"
] | B | a Punnett square is used to identify the percent chance of a trait being passed down from a parent to its offspring |
OpenBookQA | OpenBookQA-4459 | history, dust
Title: Tongue-in-cheek quote on dust extinction I remember hearing a quote or maybe rather an anecdote about a famous astronomer but I can't recall the exact wording and I also forgot who allegedly said it. Unfortunately, that has thwarted all my googling attempts.
It goes like this:
The retired astronomer gets asked by a journalist if he would do it all again and he replies something along the lines of:
Only if selective to total extinction were constant.
Is this something that really happened? If so, who said it and what is the exact wording?
Please also provide a source if possible. Well, I managed to contact the person I heard this from.
Apparently it was Walter Baade who was asked:
If you had your life to live over, would you be an astronomer again?
To which he answered:
Only if the ratio of total to selective absorption is everywhere the same.
I will not accept this answer as I have not been able to find a source yet. If anyone can find one, feel free to answer and I'll accept.
EDIT: Decided to accept after all, since apparently no one here knows a source. Follow up question regarding the source here.
The following is multiple choice question (with options) to answer.
The dust bowl happened because of | [
"two football teams",
"bowling pins",
"sweeping reform",
"unsustainable farming practice"
] | D | humans changing an environment sometimes causes that environment to be destroyed |
OpenBookQA | OpenBookQA-4460 | everyday-chemistry, analytical-chemistry, identification
It fizzed and disappeared in vinegar.
It had a yellow-orange color in blue flame.
It's salty (note that it's usually a bad idea to taste random stuff you find on your floor).
The only white crystalline material that is a plausible candidate for being there and fizzes in acetic acid (ie vinegar) is calcite - $\ce{CaCO3}$. It's also a mineral that has 'retrograde solubility' meaning it dissolves more readily in cold water. This is probably how it got to the water in the first place. This is also why it precipitates on your electric kettle. It is the same stuff.
The salty stuff that burns yellow-orange is obviously $\ce{NaCl}$, aka table salt. It also probably dissolved with the vinegar as well. Why is the salty taste not quite like table salt? Well, first of all it is mixed with calcite. But, calcite has no taste. It's possible that there is some $\ce{KCl}$ or $\ce{MgCl2}$ in there as well. They are slightly more bitter than $\ce{NaCl}$. This is the stuff they use in low sodium salt.
There's another possibility - it could be any of the epsom salt family, $\ce{MgSO4.$n$\,H2O}$.
As to would this be dissolved in the first place, you can only speculate. You say that it came from a table that was outside. Did people eat there? Could people had spilled salt on it? Is the airborne dust in your area contain a lot of calcite? What about your basement? Could someone have spilled some salts on the floor, maybe even years ago?
The following is multiple choice question (with options) to answer.
Max mixed some orange flavored powder in a glass of water until there it was dissolved. His sister tasted it and it tasted like | [
"cola",
"dark chocolate milk",
"a citrus fruit",
"lemons and apples"
] | C | dissolving a substance in water causes the water to taste like that substance |
OpenBookQA | OpenBookQA-4461 | fluid-dynamics, pressure, biophysics, explosions, shock-waves
During recompression to higher pressures,
the subcutaneous gases were, of course, also
recompressed and the animals quickly and
dramatically deflated to their normal appearance, still remaining, however, in an obvious state of flaccid paralysis, unconsciousness,
and apnea. This deflation process appeared to
begin rather gradually with the onset of recompression. At 25 to 30 mm. Hg absolute, deflation became more rapid ; at approximately
70 mm. Hg the animals appeared to have returned to their normal size. At 45 to 50 mm.
Hg, however, a major portion of the deflation
is complete, suggesting that water vapor is
probably the predominant gas concerned with
the excessive distention of the animals. The
exact pressures at which the deflation process
and the condensation of water vapor occurred
was influenced, in part at least, by the subcutaneous and deep body temperatures which,
in turn, were probably affected by the duration
of the low pressure exposures and the evaporative cooling of the body surfaces.
The rapidity of recovery during or after
recompression was generally dependent on the
duration of the low pressure exposure, the rate
of recompression, and on whether or not the
animals were recompressed with oxygen or air.
As might well be expected, the shorter the
exposure time and the faster the recompression
with oxygen, the more rapid and less complicated was the recovery period. Animals that
were exposed to the low pressure for 90 seconds
or less often began to breathe spontaneously
during the recompression to ground level.
When the exposures to the reduced pressure
were longer than 90 seconds, the depressed state
of the animals was intensified and apnea persisted for a prolonged period of time after
recompression. Under these conditions, when
first examined at ground level, the animals
were usually apneic with variations in heart
rate ranging from bradycardia to tachycardia.
They remained apneic for varying periods of
time, but spontaneous respiration always began
in less than 2 to 3 minutes, provided there was
a heartbeat. Otherwise, when no heartbeat
was detectable, the animals invariably failed to
survive. During the course of recovery, both
the heart rate and respiratory frequency increased steadily for the first 2 to 5 minutes.
Some of the animals exhibited a state of decerebrate spasticity when stimulated by being
touched or handled. Most of the animals
The following is multiple choice question (with options) to answer.
A dog can breathe | [
"under an ocean",
"out in space",
"in a church",
"in a sarcophagus"
] | C | an animal requires oxygen for to breathe |
OpenBookQA | OpenBookQA-4462 | zoology, ethology, behaviour, psychology, death
Strange thought
Organisms that have not evolved the ability to make "conscious choices" cannot decide to end their life. You will be hard-pressed to find any scientific data on this question. Psychology in humans is already a difficult study, at times failing to demonstrate results with real scientific rigor. When studying animal psychology, you face another substantial barrier - language. Although some primates have been taught to communicate with sign language, the best of them are still far from the level of proficiency of a human. We can measure brain activity and observe behavior, which can lead us to strong suspicions about what is going on in an animal's mind, but very little can actually be proven.
Mostly, all we can do is speculate about such questions. You will find some veterinarians out there who treat pets for mental conditions, but you will find at least as many people calling them quacks as those who believe in the validity of their work. And certainly, they can't prove to you that a treatment has helped an animal. It's subjective.
If we see an animal do something which in a human might reliably be interpreted as a sign of depression, it's possible that this interpretation is appropriate for the animal as well. It's also possible that there is some totally foreign unrelated explanation. The problem we find when trying to scientifically discuss matters which cannot be proven scientifically is that scientists must be careful to state what they know and nothing more. So they might say "We cannot prove that the porpoise is depressed", or "Science cannot prove the existence of a God." This is often misinterpreted as evidence against the finding - that the porpoise is not depressed; that there is no God. This is a fallacy. Rather, we should recognize that we have different ways of exploring questions like these.
The following is multiple choice question (with options) to answer.
Animals are just like humans in that if they run out of oxygen, breathing is impossible and | [
"They will perish",
"they will type.",
"they will program",
"they will Laugh"
] | A | an animal requires oxygen for to breathe |
OpenBookQA | OpenBookQA-4463 | heat, friction, everyday-life
Title: How hot does the tip of a pencil get while writing? When writing with a pencil, there seems to be quite a lot of friction - which seems like it would induce heat.
How hot would the tip of a #2 pencil get writing on normal copy paper? Graphite (pencil "lead") is an allotrope of carbon that occurs in layers of carbons arranged into hexagons, tessellating the plane. Each carbon is $sp^2$ bonded and each layer is one atom thick. The bonds holding the carbons in one plane together are incredibly strong, uniform covalent bonds of strength ~1.33, and the carbons are in a very stable hexagonal arrangement. These bonds are incredibly difficult to break, hence graphite's extraordinarily high melting point (several thousand kelvins).
By contrast, there are only weak dispersion forces holding different planes together, which are easily broken. When you write, you are breaking these bonds to leave graphite layers on the paper.
Imagine a deck of cards. Even if you're the fastest dealer in the world, the deck never heats up. Why? Because however much friction is felt at the interface between the top card and the one under it, it is only felt for a moment and then new, cool cards feel it.
The following is multiple choice question (with options) to answer.
Which is the likeliest part of a pencil to have been mined? | [
"the wood",
"the ink",
"the rubber",
"the lead"
] | D | pencil lead contains mineral graphite |
OpenBookQA | OpenBookQA-4464 | pressure, everyday-life
Title: How does sharpening a pencil make it darker? Why does a sharp pencil write better than a blunt one?
Note that the force applied on each case is identical. When you make a line on a piece of paper using a pencil, you are shearing (sliding) off layers of graphite from the pencil 'lead' and depositing them on the paper. The sharper the pencil point, the smaller the area over which the frictional force between pencil 'lead' and the paper is concentrated. So the shearing stress on the 'lead' is greater, and graphite layers slide off more copiously as you move the pencil across the paper.
The following is multiple choice question (with options) to answer.
When writing with an instrument one sharpens, the leftovers when pressed to paper is | [
"a squid",
"glowing",
"a mineral",
"bright white"
] | C | pencil lead contains mineral graphite |
OpenBookQA | OpenBookQA-4465 | earthquakes, seismology, instrumentation, in-situ-measurements, diy
Title: Using accelerometer as a seismograph I'm using ADXL345 accelerometer with Raspberry Pi to build a seismograph. I've successfully hooked it up and can plot the accelerometer data in three axis. Is there any way to express these data in the form of the magnitude of an earthquake, of course, at the point of sensing? I know that it might be imprecise, but any representation would be helpful (e.g. Richter scale), and how to accomplish that. The magnitude of an earthquake is related to the total energy released, therefore to estimate it from a seismogram you need to know the distance to the source. In the case of the Richter scale for example, the relationship between magnitude and seismogram amplitude is defined for a standard distance.
If you have only one seismograph, you can not triangulate the location of the source (hypocenter). Therefore, you can not estimate the magnitude of a seismic event (Richter or moment magnitude).
But you can estimate the local seismic intensity of the event at the particular location of your instrument. With the accelerometer data you can easily measure the peak ground acceleration, that can be used to estimate the intensity in any of the existing scales. For example, the peak ground accelerations associated to each intensity level in the commonly used Mercalli intensity scale are:
Those g values would be easy to calculate with the accelerometer data and proper calibration constants.
Table taken from the Wikipedia page for peak ground acceleration
You might want to have a look at this question. There are some nice answers and references that you might find useful.
The following is multiple choice question (with options) to answer.
A seismograph is a kind of tool for measuring the size of | [
"rivers",
"home planet tremors",
"volcanic activity",
"lakes"
] | B | a seismograph is a kind of tool for measuring the size of an earthquake |
OpenBookQA | OpenBookQA-4466 | waves
Title: Can a wave propagate in any substance? Aren't there any prerequisites? We see waves propagate in air, water, through the cristal of a metal and along a rope.
Isn't a wave a wonder of Nature, or is it just a simple phenomenon?
Are homogeneity and isotropy necessary properties for the correct propagation of waves?
Update
are a rope, water and space/EM field elastic in the same way? A wave can propagate in any medium that is:
a) elastic
b) less than critically damped
Neither homogeneity nor isotropy are necessary.
Any elastic system will return to it's original state when deformed, the question is just whether the deformation can propagate, and this is down to how quickly the energy of the deformation is dissipated. If the damping is high enough, this is critical damping, the material will return to its original state with a $e^{-\alpha t}$ dependance on time and no wave will propagate.
For example, in water common experience tells a gravity wave (i.e. a wave) propagates just fine, and a longitudinal wave (i.e. sound) propagates just fine. However shear waves will not propagate because they are too rapidly damped.
The following is multiple choice question (with options) to answer.
What property of waves matter when the ground shakes? | [
"amplitude",
"fish scales",
"oscillation",
"ground water"
] | A | a seismograph is a kind of tool for measuring the size of an earthquake |
OpenBookQA | OpenBookQA-4467 | species-identification, entomology
Title: Identify this thin and strangely-shaped dragonfly, and understand why the shape looks so weird I took these photos around noon in mid August in Hsinchu county Taiwan. I've seen many dragonfly varieties but I've never seen anything like this before.
Its body is about 5 cm long and very thin compared to the ones shown in the related questions below. The midsection looks strangely shaped to me, as if it is bent upwards in the back and suddenly ends, and a very thin "tail section" was then added below it. This dragonfly damselfly is from the species Pseudocopera ciliata. Dragon fly anatomy changes between species and there is not definitive answer for why it looks like that, the best guess i can give is that it may assist the female as she tries to find the hookup point for mating.
General Information
More Information(Pay-wall)
This is in Chinese but confirms presence in Taiwan: http://gaga.biodiv.tw/new23/s3-37.htm
The following is multiple choice question (with options) to answer.
Who stalks dragonflies south? | [
"clouds",
"electricity",
"kestrels",
"polar bears"
] | C | migration is when animals move themselves from a cooler climate to a warmer climate for the winter |
OpenBookQA | OpenBookQA-4468 | java, performance, beginner, game
instead.
4) Parts of the "lags" that you are experiencing may come from the game loop. It explicitly says
//repaints the game as fast as it can
gamepanel.repaint();
which should simply not be necessary. Swing is internally coalescing the repaint triggers. This means that when you call repaint() 1000 times in a row in a very short time, it may effectively cause the component to be painted only once. However, this does not come for free. Flooding the paint system with unnecessary repaint() triggers is certainly not beneficial. You should only call repaint() when there really have been changes. Namely, after the call to update(). (In fact, you might even consider a short Thread#sleep in the main loop, but this depends on several other factors).
5) Although it is not used yet: The method
public Rectangle getBounds(){
Rectangle ret = new Rectangle((int)x,(int)y,width,height);
return ret;
}
will create a new rectangle instance each time. This may create a lot of garbage, and eventually decrease the performance. But consider that, unfortunately, Rectangle is not immutable, so directly returning a single instance of the rectangle may not be applicable here.
The following is multiple choice question (with options) to answer.
What is changed when an object is painted? | [
"chemical makeup",
"light absorption",
"sunshine",
"rust"
] | B | painting an object a color causes that object to be that color |
OpenBookQA | OpenBookQA-4469 | collision, material-science, glass
Title: Why marbles don't shatter like a glass panel does? Both are made of the same material, not talking about the tempered glass. But I don't see marbles shatter the way glass panel does, why is that? If I could scale up the marble to the size of a car and strike a hammer on it, would it shatter? The difference is geometry, both in shape and size.
First, consider that the smaller something is, the stiffer it is in general. Take a large rubber eraser and squeeze it (in compression, not bending) and then cut it in half and squeeze again. You need double the force to get the same deflection with half the size.
Next is the shape, where something flat like a glass pane is allowed to bend which puts the most strain into the material, compared to a sphere that mostly compresses. The details here are complex, but certain shapes are stiffer and certain ones are more complaint. A sphere is exceptional at resisting loading because most of the internal stresses are compressive.
Brittle shattering occurs when the bonds between molecules in a solid break (in tension) causing a dislocation, which then loads up neighboring molecules which in turn break also. In the end, there is a runaway process of crack propagation until the object is fully cracked.
The following is multiple choice question (with options) to answer.
Marble is unable to form while lava | [
"is still hot",
"hardens",
"cools down",
"offends the volcano"
] | A | minerals are formed from magma cooling |
OpenBookQA | OpenBookQA-4470 | volcanology, volcanic-hazard
In any case, if you do manage to reach the last eruption site, don't walk on the lava flow crust in the hope to see some active lava. I did it with a group of visiting volcanologists, guided by local volcanologists who had been in the field every day for six months. They knew the site very well and we just followed their tracks. It can remain dangerous for months. I hope that you'll get to see this wonder of nature, but don't risk your life for it!
The following is multiple choice question (with options) to answer.
You are hiking up the side of an inactive volcano, what are you most likely to find? | [
"Mercury",
"Diamonds",
"Minerals",
"Gold"
] | C | minerals are formed from magma cooling |
OpenBookQA | OpenBookQA-4471 | geology, mountains, geomorphology
Title: Why are the mountains predominately grey or dark brown? Observing many photos of mountains one can assume that most of the mountains are grey or brown. See also the mountain article at Wikipedia.
There are however several ways a mountain can form, which allow for exposure of various rocks, still mountains are mostly grey/brown.
Why is it so?
Why isn't there a single mountain out of Olivine, Pyrite, Tourmaline or, say, Autunite, or any other brightly coloured rock?
...which allow for exposure of various rocks, still mountains are mostly grey/brown.
The colourful minerals are apparent when you look up close. When you look from far away, the minerals are all mixed in your vision. My 2-year old daughter prepared a wonderful example of how this works:
Take a bunch of beautiful bright water colours, mix them together, and you end up having a greyish brown, dull colour.
Take another example. Sand, or sandstone. Boring yellow, white, or brown. But it's basically quartz. Finely divided quartz, unlike any of the beautiful quartz crystals you see for sale. Grain size is an important factor of the perception of colour.
That said, one of the skills geology undergraduates learn in their first year of university, is distinguishing colours in a geological context. What to the untrained eye may seem brown or grey, appears like a world of colour. I still remember that when I just started my geology B.Sc about 10 years ago, we were given a bunch of rocks that all looked grey. After one year, they did not look grey any more. They were red-grey, brown-grey, blue-grey, green-grey, etc.
Mountains can be coloured. Here are some pictures that I took myself a while ago:
On a closer look I'm certain you will see that there are many colours in there: green, yellow, orange, pink, red, brown, white, black. No need for geological education to see that.
Why isn't there a single mountain out of Olivine, Pyrite, Tourmaline
or, say, Autunite, or any other brightly coloured rock?
Most rocks are not composed of a single mineral. However, there are rocks composed only of olivine. They're call "dunites". Here's one:
The following is multiple choice question (with options) to answer.
Which substance is likely present for the birth of a mountain? | [
"venom",
"peat",
"magma",
"sunlight"
] | C | mountains are formed by volcanoes |
OpenBookQA | OpenBookQA-4472 | exoplanet
It's probably possible to have volcanic eruptions even though dozens or maybe even hundreds of miles of exotic ice because the heat has to go somewhere, eventually, assing it's likely to build up over time, so either by circulation of eruption, the heat has push through at some point. This even happens on so called "dead" planets like Mars or even the Moon. Mars still has the occasional volcanic eruption, just not very often.
But water worlds certainly can have plate tectonics. There's nothing in the water that would prevent it from happening. Plate Tectonics is, as I understand it, primarily a factor of the size of the planet. Gas planets - different story, but planets with a hard surface, Earth sized, a tiny bit smaller to a fair bit but not much bigger are good candidates for plate tectonics (I think). There's some debate on how large, I think, still going on. But I remember reading that ocean/water worlds might even be more likely to have plate tectonics. Plate tectonics is definitely something we'd look for if we ever get a close enough look at other planets in different solar-systems (exoplanets).
Just my thoughts on this. Not meant to be complete or definitive.
The following is multiple choice question (with options) to answer.
Volcanoes, have a | [
"Esophagus",
"Camels",
"Emotional experience",
"Cigarettes"
] | A | mountains are formed by volcanoes |
OpenBookQA | OpenBookQA-4473 | optics, scattering, atmospheric-science
To the comment:
Could you explain why the effect of ozone is more important after sunset? Why doesn't this change the story during sunset, or during the day?
During the day sunlight passes much smaller distances through the atmosphere, thus is absorbed less. For the same reason it's reddened less by Rayleigh scattering, leaving more blue light to make the sky blue. Thus ozone has much smaller effect on daytime sky.
During sunset much of the sunlight passes through the troposphere, getting redder, while getting scattered into the observer more than from the stratosphere where most of the ozone layer is located (due to higher concentration of air molecules). So the ozone absorption effect is also less pronounced.
And at twilight the Earth's shadow prevents light from passing through troposphere, making the only light visible scattered from the stratosphere and above, and this light in large part gets there through the ozone layer, traversing it through the long dimension.
I have actually tested this ozone explanation of blue hour, using the Precomputed Atmospheric Scattering code to render two versions of the same scene: one for atmosphere with an ozone layer and another without any ozone. Here are the renderings of the Belt of Venus (ignore the white sphere in the center, it's just an irrelevant part of the demo scene):
With ozone layer (the normal Earth atmosphere):
Without any ozone:
The following is multiple choice question (with options) to answer.
Above your head, the daylight sky is gloomy and dark, despite the hour of day. The wisest thing to bring with you on this summer afternoon is | [
"a bikini",
"a picnic lunch",
"garden shears",
"an umbrella"
] | D | grey clouds are a source of precipitation |
OpenBookQA | OpenBookQA-4474 | waves, acoustics, atmospheric-science, weather
Even with the question of attenuation - when visibility is reduced to 40 ft, echolocation will probably beat it handsomely at intermediate distances. There are a couple of other interesting things you can do to improve your ability to see in fog.
1) Yellow "driving glasses". These work because they cut out the blue components of light. When fog droplets are very small, light scattering is in the Rayleigh regime - that is, scatter probability goes as the inverse fourth power of the wavelength, and blue (400 nm) light is 16x more scattered than red (800 nm) [note - using round numbers...]. By cutting out the blue component, you reduce the amount of scatter that reaches the eye and improve the contrast. Skiers also use yellow "fog glasses".
2) Scanning light source. This is one of those magical things that ought not to work but does. With normal (flood) illumination, light scatters "from everywhere to everywhere". If instead you look along the line of (say) a laser shining into the fog, then the only scattered light you see is the light that scatters exactly 180 degrees back at you - which is a small fraction of all the scattered light. If you scan the light source and detection system in sync, and very quickly, you can build up an "almost scatter free" image. This raster scanning technology is used in some underwater search applications and can penetrate about 6 "attenuation lengths". As was discussed in the comments, this method actually works best when the viewing angle is not exactly 180 degrees - not only is the back scatter from the fog weaker (there is a curious doubling of scatter intensity that happens at exactly 180) but also, by looking at a slight angle, you are able to eliminate the back scatter from the closest fog - greatly improving penetration.
More recently researchers in Israel have come up with a way to image through thin layers of scattering material - as you can see in the link, they are also able to see "through fog" (although it was not clear to me whether their technique can apply to actual imaging in fog).
The following is multiple choice question (with options) to answer.
Visibility while driving is decreased by bad what? | [
"local forecasts",
"roads",
"music",
"trees"
] | A | bad weather decreases visibility while driving |
OpenBookQA | OpenBookQA-4475 | meteorology, snow, radar
Also note that winter precipitation adds an extra complication because the particles are lighter in weight and can thus be blown about more by vertical and horizontal winds. Raindrops (and hail) are quite likely to fall unless extreme updrafts exist because they are heavy. But drizzle, snow, and sleet may be blown around quite a bit. Without a time-intensive dual-Doppler analysis, you cannot know the wind motion in the storm thoroughly, and therefore will have varying results at times.
And finally, the big wrench is unfortunate inherent to how radars work. They measure the percentage of their sent energy that is reflected back to them. That's great because that's directly connected to the diameter of the item falling (to the 6th power). But unfortunately the grand problem is that in a storm, there is a huge variety of drop/flake sizes mixed together at once... such that we can't extract which combination of particle sizes created it (and thus can't calculate volume to actually know the rain/snow amount that falls). It could be like 6 medium size flakes causing the 10 dBZ echo... or 2 large flakes and 10 small flakes... and each combination is a different volume/snow total. (to see the nitty-gritty math details on this, read more here.) So we can never know for sure the exact rain/snow falling using just radar. The good news is we've at least done lots of experiments and come up with some fairly useful best-practice formulas for using the Z-R ratio in different scenarios. Good, but not perfect.
The following is multiple choice question (with options) to answer.
Driving during a snow storm or strong thunderstorm is a bad idea because bad weather makes it | [
"harder to see",
"Easier to see",
"able to fly",
"glasses"
] | A | bad weather decreases visibility while driving |
OpenBookQA | OpenBookQA-4476 | ocean, oceanography, sea-level, tides
However, I'm really curious as which are the most important amongst them? Or is it even possible to guess the tide height if I know the Lunar phase and I have a good globe with sea depth? I don't know about the size of land masses, but their distribution and the shape of ocean basins definitely play a big role.
When considering the ideal case of an all-ocean globe, i.e. one with no land masses (equilibrium tidal theory), the combined effect of sun and moon give a theoretical tidal range of less than 1 m(1). As tidal ranges can be much larger than this, there are other effects that has a greater influence.
The Bay of Fundy for example, is one of the places with the largest difference between low tide and high tide, at about 16 m. The large difference in this location has to do with the shape of the bay. The bay has a natural frequency for waves that is about the same as the frequency of the tide itself, giving an amplification of the tidal amplitude. In addition there is a funnelling effect in the inner part of the bay, giving an additional contribution.(2)
Another example of large tidal differences is the English channel, particularly the French side. In this case the tides are large at least partly because the tide moves as a coastal trapped Kelvin wave. These are waves that propagate along land, with the land to the right when looking in the direction of propagation (on the Northern hemisphere, land to the right on SH). The amplitude of the wave is highest near the coast, decaying exponentially away from the coast. As the tide in the English channel moves northward, the largest tidal range is on the French side.
With regard to guessing the tidal range, this is not entirely straight forward.
First, when discussing tides, we generally split the tidal potential into a series of oscillations having different frequencies, mainly either diurnal (period of ~24 h) or semi-diurnal (period of ~12 h).
These given frequencies are obtained through trigonometric considerations, and depend on the latitude of the point, the declination of the moon or sun relative to the equator, and the hour angle.
(The hour angle is basically the longitudinal difference between the sub-lunar point and the point we consider.)
Each of these components can vary in time and space.
The following is multiple choice question (with options) to answer.
_____ tide is a stage in the tide cycle process that surfers like the best | [
"low",
"mud",
"high",
"earthy"
] | C | high tide is a stage in the tide cycle process |
OpenBookQA | OpenBookQA-4477 | thermodynamics, energy, home-experiment
Note 3: Peak hours tend to be during the day (this may reverse if we get wide-spread solar energy), so keeping the house cool during the day would cost even more. You pretty much have it right. We have two scenarios:
1 - Leave air conditioning on all day. Say that outside temperature is 90 degrees and inside temperature is 70 degrees. Then, all day long, the air conditioning has to remove any heat that gets into the house continuously. Heat transfer depends on the difference in temperature between outside and inside the house. In this case, heat transfer per unit time is equal to a constant K times 20 degrees. Over a whole day of D units of time, the total energy removed by the air conditioner is $20KD$ This assumes that convection (ie air draft) can be neglected.
2 - Stop the air conditioning during the day. If you stop the air conditioning, the flow of heat in the house initially will be the same. However, as time goes by, the inside temperature will increase. This will gradually reduce heat flow as it is proportional to the difference in temperatures. If the house is small enough and badly insulated, you could even get to a point where the inside temperature is equal to the outside temperature, at which point no more heat enters the house. When you get back from work, or if you have a timer a bit before, air conditioning is restarted. You now have to remove all the accumulated heat. However, since less heat entered the house over the duration of the day than if you had kept the air conditioning on, you have less work to do to cool down the house. Yes, the heat will have accumulated in insulation, furniture, walls, etc, but it doesn't matter. There is less heat total to remove.
The following is multiple choice question (with options) to answer.
As the hours tick passed noon and the day warms, the cottage living room will | [
"match the outdoors",
"chill down",
"be cool",
"lower temperature"
] | A | as temperature during the day increases , the temperature in an environment will increase |
OpenBookQA | OpenBookQA-4478 | newtonian-mechanics
I should add that the above is simply what I, as a physicist with a fairly long experience, suspect is what is going on. It is not something I have read about and I am sure there is somewhere a more thorough discussion. So I hope I am right; I think I have a good argument. As I have described it above, I have in mind mainly the last part of the process where the wood only moves a little relative to the metal. In the earlier part, when the wood moves through a larger distance, it is inertia that is the main consideration, just like in the party trick where you abruptly whisk away a table cloth and the dishes on the table stay where there are. The more abrupt the better.
Added remark
It occurred to me that there is another thing worth mentioning here, that makes this method preferable to resting the axe head on something, or supporting the handle on a work top and hitting the head. It is that by hitting the end of the handle, with the head just hanging, you are going to deliver the force more accurately at the join, because it travels along the handle in exactly the direction you want. If instead you strike the head then there is a danger it will be knocked slightly obliquely, introducing a random tilt with each blow, which is liable to deform the wood and thus loosen the fit.
The following is multiple choice question (with options) to answer.
Without this a sword would be made of wood | [
"safety regulations",
"ice",
"ore",
"cheap labor"
] | C | rocks often contain large amounts of metal |
OpenBookQA | OpenBookQA-4479 | visible-light, acoustics, everyday-life
Title: Why does a tubelight make noise when switched on? I have noticed that when certain tube-lights are switched 'ON' , they make certain noise corresponding to their "blinking".
In blinking, there are alternate periods of the tube lighting up and then going out. The "sound" is heard at the instant the tube lights up.
I can not properly describe the "noise" or the "sound" I'm referring to, but it seems as if the tube-light is struck gently with something. It feels as if the gas molecules inside the tube-light are striking its inner surface.
Can anybody explain this ? I am not sure, but I suspect what you hear is sound from the ballast as the field changes in it, causing it to physically change size slightly. You get similar thumps from large transformers as they are powered on.
The ticking sound as the tube warms up happens significantly later in my experience: it's just the normal slip-stick sound that lots of things made from parts make as they warm or cool (car engines, notably).
A test of this theory would be to take a tube light fitting apart and separate the ballast from the tube (just by adding suitably long wires) which would allow you to tell what makes the noise. Don't do this experiment unless you are competent with mains electricity!
The following is multiple choice question (with options) to answer.
Which makes a sound when you interact with it? | [
"something invented by Pasteur",
"something invented by van Leeuwenhoek",
"something invented by Sax",
"something invented by Galileo"
] | C | musical instruments make sound when they are played |
OpenBookQA | OpenBookQA-4480 | ros, force, uwsim
Originally posted by ZYS on ROS Answers with karma: 108 on 2016-10-03
Post score: 0
Hi,
Actually setting the friction force to thrusters will not assure constant speed due to the vehicle inertia. Vehicle needs to accelerate from stop so it will slowly gain speed. Furthermore friction depends on the velocity the vehicle is moving so you will need to dynamically adjust it. So the best option is use a controller, the most basic is a PID: wikipedia. There is a tutorial about how to create it in UWSim using Matlab/SImulink here, but it is pretty straight forward to implement it yourself.
Edit:
Some comments after reading your problems, thrusters effort ranges from -1 to 1 so setting higher effort will not help. Also check keyboard controller is not running as it sends 0's to the thrusters effort (default dynamics launcher, runs this node). Anyway a big part of navigation involves controlling the vehicle speed, but if you are not testing this just use it in kinematic mode. About the oscillating speed in a PID try adjusting the parameters and use small values, obtaining good values is not trivial, there is a lot of research work about this. Just using a P controller with a small value should be enough to achieve a reasonable result like this: effort=(vel_reference-velocity)*P . It may not achieve the desired velocity or do it slowly but should work.
Originally posted by Javier Perez with karma: 486 on 2016-10-04
This answer was ACCEPTED on the original site
Post score: 0
The following is multiple choice question (with options) to answer.
With the addition of thrusters your forward momentum will | [
"stop",
"increase",
"decrease",
"stall"
] | B | a force continually acting on an object in the same direction that the object is moving can cause that object 's speed to increase in a forward motion |
OpenBookQA | OpenBookQA-4481 | optics, everyday-life, reflection
Title: What are natural retro-reflectors? Recently I was on an airplane on a sunny day. The sun was shining on the other side of the plane and noticed a bright patch on the ground following beside us. Eventually I noticed a dark centre to this bright patch, the plane's shadow, which became more distant as the plane descended. When the plane flew over a city road signs in this bright patch lit up brightly because of their retro-reflective paint.
My question is, what was acting as a retro-reflector to produce this bright patch when it wasn't passing over a road sign? When flying over water the bright patch disappeared, or was very faint. I could see it over forests, more clearly over cut grain fields and, at least faintly over a wide range of terrain. It sounds like a version of the glory, or more likely heiligenschein, due to spherical droplets of water in the air or dew on the ground.
The following is multiple choice question (with options) to answer.
A reflector is used to reflect | [
"dirt",
"sunbeams",
"cosmic dust",
"solar heat"
] | B | the moon reflects sunlight towards the Earth |
OpenBookQA | OpenBookQA-4482 | star, planet, telescope, light, space
Title: How do I know what I'll be able to see? So I live in a suburb in Victoria, Australia. Less than an hour away from the city and I guess there is a bit of light pollution because from my backyard I can probably only see about 15 - 20 stars (probably less), I'm wondering what these stars are, and what I'll see when I get this telescope:
https://www.opticscentral.com.au/saxon-707az2-refractor-telescope.html?___SID=U#.WXQNMtN940r
This is going to sound stupid but how do I know when there are planets in the sky that I can see? I don't think I've ever actually seen a planet other than the moon.
Thank you. Firstly, if you're planet spotting, don't worry too much about light pollution. The planets are some of the brightest objects in the sky and some (especially Jupiter) can easily be observed even with a full Moon - the full Moon (along with the Sun!) is the biggest contributor to light pollution!
Take a look at the list of brightest stars ( https://en.wikipedia.org/wiki/List_of_brightest_stars ), which also contains estimates for the brightness of the Sun, Moon and major planets. There aren't typically any stars brighter from Earth than Venus, Jupiter, Mars and Mercury and precious few brighter than Saturn. I'm going to suggest you probably have seen many of the planets - but just didn't recognise them.
+1 for Stellarium ( http://www.stellarium.org/en_GB/ ). It's free, intuitive and very visual to use. You can put in your local viewing location and it gives you a view for any time of the night, future or past. At the time of writing (23 July 2017), Saturn and Jupiter should be looking good for the Southern Hemisphere. This rotates throughout the year, and Stellarium will help with this.
Do a web search for "the sky at night in the southern hemisphere" and you'll find a number of examples of websites with highlights to look for when you get out.
Couple of final suggestions:
The following is multiple choice question (with options) to answer.
Who'd be able to see a rose is pink at night? | [
"rocks",
"the Rio Grande",
"a beeping sound",
"lemurs"
] | D | the moon reflects sunlight towards the Earth |
OpenBookQA | OpenBookQA-4483 | thermodynamics, physical-chemistry, combustion
Title: Is there an 'intuitive' explanation for "Which burns more?" In helping a friend's son with his grade 10 science homework, I came across a question that essentially asked the following:
"If two objects of equal mass but different specific heat capacities are touched, which will burn more?"
The wording of the question implied that this was meant to be a thought experiment rather than anything calculation-based.
My first reaction was that this question was probably quite a bit more complex than it was made out to be; a quick search online and on this site confirms this, however ideas like conductivity (which I'm familiar with), diffusivity & effusivity (which I'm not) and others are well beyond the student's understanding at the moment. I also felt "burn more" was rather vague.
To address these concerns, I made the following two assumptions:
since the question made no reference to time, I took the phrase "burn more" to mean "transfer the most energy by the time equilibrium has been reached"
all parameters like mass (mentioned in the question), density, conductivity, area of contact, etc., other than specific heat capacity and time would be equal.
The following is multiple choice question (with options) to answer.
Which is hotter? | [
"the snow on one's car",
"a recently used iron",
"a rainbow sherbet cone",
"a cup of iced tea"
] | B | a hot substance is a source of heat |
OpenBookQA | OpenBookQA-4484 | Please press Kudos if this helped
“Going in one more round when you don't think you can, that's what makes all the difference in your life.”
Re: Two bottles are partially filled with water. The larger bottle current &nbs [#permalink] 04 Sep 2018, 22:21
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The following is multiple choice question (with options) to answer.
The people who live after you will appreciate it if you take your glass bottles and | [
"throw them",
"break them",
"reuse them",
"shatter them"
] | C | recycling resources has a positive impact on the environment |
OpenBookQA | OpenBookQA-4485 | botany, plant-physiology, reproduction, plant-anatomy, life-history
In dimorphic cleistogamy CL and CH flower differ in the time or place
of production, with CL flowers produced in conditions (underground,
low light levels, early in the season) that are potentially
unfavorable for outcrossing.
In induced cleistogamy potentially CH flowers that experience conditions such as drought or low temperatures fail to open and self-pollinate, becoming, in effect, CL flowers.
You should check out the Culley and Klooster (available online if you make a jstor login) – they discuss complete cleistogamy which addresses your last question. They report several completely CL species in their Table 1, and give references.
More generally, many different plant groups maintain balances of self-pollination and outcrossing (i.e. "real sex"), through an even more diverse set of mechanisms.
Even more generally, many plants and some animals maintain balances of sexual reproduction and clonal reproduction, through an even more diverse set of mechanisms. For instance, vegetative reproduction (e.g., strawberry runners) is very common in many plant groups; facultative and obligate parthenogenesis in animals also occurs.
Culley, Theresa M. and Matthew R. Klooster (2007). The Cleistogamous Breeding System: A Review of Its Frequency, Evolution, and Ecology in Angiosperms. Botanical Review. Vol. 73, No. 1, pp. 1-30
The following is multiple choice question (with options) to answer.
Pollination is required for what reproduction? | [
"elephant",
"bug",
"bird",
"flora"
] | D | plant reproduction requires pollination |
OpenBookQA | OpenBookQA-4486 | botany, plant-physiology, reproduction, plant-anatomy, life-history
In dimorphic cleistogamy CL and CH flower differ in the time or place
of production, with CL flowers produced in conditions (underground,
low light levels, early in the season) that are potentially
unfavorable for outcrossing.
In induced cleistogamy potentially CH flowers that experience conditions such as drought or low temperatures fail to open and self-pollinate, becoming, in effect, CL flowers.
You should check out the Culley and Klooster (available online if you make a jstor login) – they discuss complete cleistogamy which addresses your last question. They report several completely CL species in their Table 1, and give references.
More generally, many different plant groups maintain balances of self-pollination and outcrossing (i.e. "real sex"), through an even more diverse set of mechanisms.
Even more generally, many plants and some animals maintain balances of sexual reproduction and clonal reproduction, through an even more diverse set of mechanisms. For instance, vegetative reproduction (e.g., strawberry runners) is very common in many plant groups; facultative and obligate parthenogenesis in animals also occurs.
Culley, Theresa M. and Matthew R. Klooster (2007). The Cleistogamous Breeding System: A Review of Its Frequency, Evolution, and Ecology in Angiosperms. Botanical Review. Vol. 73, No. 1, pp. 1-30
The following is multiple choice question (with options) to answer.
Which likely aids in plant reproduction? | [
"the gravity on Mars",
"the influx of human pollution",
"the cooking of rice pilaf",
"a family of badgers hunting and gathering"
] | D | plant reproduction requires pollination |
OpenBookQA | OpenBookQA-4487 | python, beginner, python-3.x
while True:
self.fertilizer = int(input("Please enter the amount of fertilizer (scale 0-10): "))
if self.fertilizer not in range(11):
print("***NOT A VALID AMOUNT***")
continue
if self.fertilizer == self.Plants.preferred_fertilizer:
self.fertilizer_score = 10
break
elif self.Plants.preferred_fertilizer - 2 <= self.fertilizer <= self.Plants.preferred_fertilizer + 2:
self.fertilizer_score = 7
break
else:
self.fertilizer_score = 4
break
# Automated weed removal: random score
count = 0
while self.weed == True:
x = 1* random.random()
count += 1
if x < 0.3:
self.weed == False
print("You have removed the weeds", count, "times to help the plant grow. Good job!\n")
break
if count <= 3:
self.weed_score = 10
else:
self.weed_score = 5
# Calculate probability of fruit growth. Weight of parameters: water 30%, fertilizer 30%, soil type 10%, - user selection
# weed 20%, temperature 10% - random
self.probability = 0
if self.Environment.soil_type == self.Plants.preferred_soil:
self.probability += random.uniform(0.7, 0.9) * 0.1
else:
self.probability += random.uniform(0.3, 0.5) * 0.1
if self.Environment.temp_return == self.Plants.preferred_temp:
self.probability += random.uniform(0.7, 0.9) * 0.1
else:
self.probability += random.uniform(0.3, 0.5) * 0.1
The following is multiple choice question (with options) to answer.
What is undesirable in a vegetable garden? | [
"tomatoes",
"green peppers",
"corn",
"dandelions"
] | D | if a weed is pulled then that weed is destroyed |
OpenBookQA | OpenBookQA-4488 | species-identification, botany
Title: Succulent weed identification There is a succulent-looking weed growing in a crack in my driveway. What is it?
Conditions: Dry, full sun, asphalt & gravel, no competition.
Date: 2018-07-16
Location: Toronto, Ontario, Canada
Size: 40cm x 40cm x 2cm This is Common purslane, Portulaca oleracea. It is used in salads, although it contains oxalic acid and there are poisenous plants resembling Purslane, see comment below.
https://en.m.wikipedia.org/wiki/Portulaca_oleracea
The following is multiple choice question (with options) to answer.
If a weed is pulled then the weed is what? | [
"fruitful",
"terminated",
"functioning",
"ugly"
] | B | if a weed is pulled then that weed is destroyed |
OpenBookQA | OpenBookQA-4489 | development
Title: How detachment/separation works in biology? It might be a strange question, but I'm interested in the mechanics of separation/detachment during asexual reproduction, for example when an organism reproduces by budding (I don't mean cellular budding like baker's yeast). When the newly formed body is fully matured it detaches itself from the parent / original body.
It might not be caused by a specific tissue, as animals with not so differentiated bodies are (also) capable of such, but I could easily be wrong. Is this (the detachment) triggered by changes in the cell membrane? I can't really think of other explanations. Reproductive budding and what you call 'cellular budding' are really highly related processes. Budding as a form of reproduction essentially partitions protein aggregates and damaged cellular components into the host or mother and builds fresh or 'young' cells on the opposite side of a partition. To begin understanding this look at Saccharomyces cerevisiae (budding yeast) which forms protein rings (from the septin proteins) at the membrane, around the bud neck which separates the mother and daughter cells Hartwell 1971. This ring acts a partition that in part, withholds protein aggregates and certain proteins from diffusing from the mother to the daughter. This protein ring is an example of how cells limit diffusion of proteins and cellular components to the daughter cell. Another good example that comes to mind is Linder 2007, though it is done in E Coli, not budding yeast, where mother cells maintain protein aggregates and age, while the daughter cells are given fresh components and are therefore more fresh and 'young'.
Now like you mention, imagine this process in a multicellular organism to be fundamentally the same. At some point the multicellular organism will start an outgrowth of cells, while restricting what materials are given to the daughter cells to maintain their youth. And eventually a new organism will have been created. Some of the details will be different, but the fundamental process is is quite similar. In that you start with an old cell that creates a new cell from scratch, but rather than splitting all cellular components equally between mother and daughter, the daughter cells is made in peak condition while the mother cell retains much of the cell 'junk' like protein aggregates.
Hopefully that starts to answer your question.
The following is multiple choice question (with options) to answer.
A space exists where there is room for things with cells to propagate, so it is most likely | [
"habitable",
"desolate",
"a vacuum",
"harsh"
] | A | when a habitat can support living things , living things can live in that habitat |
OpenBookQA | OpenBookQA-4490 | civil-engineering
Other things that can be done is to place hay bales, or rocks, on the soil slope and on the slope above the deposited soil. These can help to reduce the speed of surface water running down the slope.
If hay bales are used they should be placed in a staggered, off-set pattern, so that long drainage channels, which would lead to the formation of erosion gullies, are not created by the bales.
Moonscaping of the upper natural slope, above the deposited soil slope would also help in preserving the deposited soil slope.
The following is multiple choice question (with options) to answer.
Some animals use rocks as a means of what when there is bad weather? | [
"nothing",
"Deaf",
"safeguarding themselves",
"cheese"
] | C | rocks are a source of shelter for small animals in an environment |
OpenBookQA | OpenBookQA-4491 | life, extremophiles
Title: How close to Earth's core can organisms live? We don't to know much about organisms living deep below the Earth's crust. Recently a team led by S. Giovanni discovered some microbes 300 m below the ocean floor. The microbes were found to be a completley new and exotic species and apparently they feed off hydrocarbons like methane and benzene. Scientists speculate that life may exist in our Solar System far below the surface of some planets or moons. This raises some questions:
What is the theoretical minimum distance from Earth's core where life can still exist. Please explain how you came up with this number. For example, there are temperature-imposed limits on many biochemical processes.
Is there the potential to discover some truly alien life forms in the Earth's mantle (by this I mean, life which is not carbon based, or life which gets its energy in ways we have not seen before, or non DNA-based life, or something along these lines)?
What is the greatest distance below the Earth's crust that life has been discovered? I believe it is the 300 m I cited above, but I am not 100% sure. There's a lot we don't know about life in deep caves, but we can bound the deepest living organism to at least 3.5 kilometers down, and probably not more than 30 kilometers down.
The worms recovered from deep mining boreholes are not particularly specifically adapted to live that far down: they have similar oxygen/temperature requirements as surface nematodes.
The Tau Tona mine is about 3.5 kilometers deep and about 60˚ C at the bottom. Hydrothermal vent life does just fine up to about 80˚C, and the crust gets warmer at "about" 25˚C per kilometer. It's entirely reasonable to expect life to about 5 kilometers down, but further than that is speculation.
Increasing pressure helps to stabilize biological molecules that would otherwise disintegrate at those temperatures, so it's not impossible there could be life even deeper. It may even be likely, given that the Tau Tona life breathes oxygen.
I am certain no life we might recognize as life exists in the upper mantle.
The following is multiple choice question (with options) to answer.
Which would likely live under a rock? | [
"an eagle",
"a cat",
"a vole",
"a dog"
] | C | rocks are a source of shelter for small animals in an environment |
OpenBookQA | OpenBookQA-4492 | evolution, zoology, anatomy, species
Title: Examples of animals with 12-28 legs? Many commonly known animals' limbs usually number between 0 and 10. For example, a non-exhaustive list:
snakes have 0
Members of Bipedidae have 2 legs. Birds and humans have 2 legs (but 4 limbs)
Most mammals, reptiles, amphibians have 4 legs
Echinoderms (e.g., sea stars) typically have 5 legs.
Insects typically have 6 legs
Octopi and arachnids have 8 legs
decapods (e.g., crabs) have 10 legs
....But I can't really think of many examples of animals containing more legs until you reach 30+ legs in centipedes and millipedes. Some millipedes even have as many as 750 legs! The lone example I am aware of, the sunflower sea star, typically has 16-24 (though up to 40) limbs.
So my question is: what are some examples of animals with 12-28 legs? As a couple of counterexamples, species in the classes Symphyla (Pseudocentipedes) and Pauropoda within Myriapoda have 8-11 and 12 leg pairs respectively, so between 16 to 24 legs (sometimes with one or two leg pair stronlgy reduced in size).
(species in Symphyla, from wikipedia)
Another common and species-rich group with 14 walking legs (7 leg pairs) is Isopoda.
(Isopod, picture from wikipedia)
You also need to define 'legs' for the discussion to be meaningful. As you say, decapods have 10 legs on their thoracic segments (thoracic appendages), but they can also have appendages on their abdomens (Pleopods/swimming legs), which will place many decapods in the 10-20 leg range.
(Decapod abdominal appendages/legs in yellow, from wikipedia)
So overall, in Arthropoda, having 12-28 legs doesn't seem all that uncommon. There are probably other Arthropod groups besides those mentioned here that also have leg counts in this range.
However, for a general account, the most likely answer (if there is indeed a relative lack of 12-28 legged animals) is probably evolutionary contingencies and strongly conservative body plans within organism groups.
The following is multiple choice question (with options) to answer.
There will be more rattlesnakes if a rattlesnake has | [
"more scales",
"more eggs",
"more venom",
"more rattles"
] | B | as the number of eggs laid by an animal increases , the number of eggs that hatch will increase |
OpenBookQA | OpenBookQA-4493 | 1. all chicks peck to the left. 0% of chicks are unpecked.
2. all chicks peck to the right. 0% of chicks are unpecked.
3. all chicks, divided in pairs, peck each other, 0% of chicks are unpecked.
4. chicks are divided in groups of 4, where the pair in the middle pecks each other, while chicks on the edge peck this pair in the middle. 50% of chicks are unpecked.
There are however other possible probability distributions. Two new patterns emerge from this.
1. chicks are divided into groups of 3, where a pair of chicks pecks each other and one chick from this pair is double pecked by a chick on the LEFT. This chick on the left is unpecked which makes a total of 33%. The last, 100th chick can peck randomly left or right but remains unpecked itself as in example 4). This gives 34 unpecked chicks.
2. chicks are divided into groups of 3, where a pair of chicks pecks each other and one chick from this pair is double pecked by a chick on the RIGHT. The last, 100th chick can peck randomly left or right but remains unpecked itself as in example 4). This gives 34 unpecked chicks.
A mixture of all those sets of outcomes are, of course, also possible. Now we can calculate the median of these 6 possible outcomes: (0+0+0+50+34+34)/6=19.666 somewhat lower than the original solution.
The following is multiple choice question (with options) to answer.
Female birds sit in what? | [
"assorted materials",
"trash cans",
"chimneys",
"boxes"
] | A | female birds sit in nests |
OpenBookQA | OpenBookQA-4494 | agriculture
The primary cereals for making bread are wheat and rye, while barley and oats may be mixed in. Historically significant portions of the rural population of Europe were sustained by cereal-based food in the form of gruel and porridge rather than by bread, especially prior to the introduction of the potato. Barley can be consumed in the form of pearl barley and groats and oats in the form of oatmeal. Especially in cool and humid climates not very suitable for cultivating wheat and rye, oats were once commonly cultivated and consumed. When Samuel Johnson wrote his dictionary, he famously defined oats as: "A grain which in England is generally given to horses, but in Scotland supports the people." A major historical and modern use of barley has been as malted barley, the main ingredient in beer brewing.
In the case of Finland it is interesting to note how late the transition from slash-and-burn agriculture to the use of permanent fields occurred. According to Teija Alenius, Environmental change and anthropogenic impact on lake sediments during the Holocene in the Finnish − Karelian inland area, Ph.D. thesis, University of Helsinki, 2007 (online)
The following is multiple choice question (with options) to answer.
Corn and wheat are among the favorite foods of | [
"humans",
"grizzly bears",
"fish",
"aliens"
] | A | humans eat crops |
OpenBookQA | OpenBookQA-4495 | agriculture
Title: What does "permanent field" mean in agriculture? I am reading a book that in a paragraph talks about the agricultural methods used in prehistoric Finland.
The further north and east, the more extensive the amount of
burn-beat cultivation, which was a far from primitive form of
agriculture. The yield was many times higher (twenty- to thirty-fold)
than on permanent fields (five- to ten-fold), and there were multiple
varieties of the technique
A history of Finland by Henrik Meinander.
One of them is burn-beating. Like I understand, in burn-beating people cut down the trees in the forests and burn the topsoil. This way they can use that soil for 3 to 6 years for cultivation.
The other method is permanent field. I have searched the internet and the result I got was "permanent crops", like here. In which case people planted trees once in a field and harvested them multiple times.
But in another research about prehistoric Finland it was saying:
The site of Orijärvi shows that permanent field cultivation, with
hulled barley as the main crop was conducted from approximately cal AD 600 onwards.
The following is multiple choice question (with options) to answer.
Some farmers make a very good living because the crops they grow are sold to lots of people for | [
"feeding to Mars",
"sustenance",
"gravity",
"metal"
] | B | humans eat crops |
OpenBookQA | OpenBookQA-4496 | optics, visible-light
Title: Does passing through a colored medium cause light to become that color or to lose that color? Why is the atmosphere different? It's well known the effect of Rayleigh scattering on the color of the sun, and it's explained several times on this website. Here's one of them. The summary of these explanations is, that when light travels through a colored medium, that color is being "used up" to make the medium the color it is, and only the other colors will go through.
Make very much sense. But the problem is that our experience in everyday life is just the opposite. When we shine a light through a colored medium, the light becomes the same color as the medium. Although it's hard for me to understand why (this was asked here without an impressive answer). And that's also happening with sunlight that goes through colored glass.
So why does the atmosphere behave different than anything else? And is there anything I can experiment with that would have the same behavior as the atmosphere? There are two mechanisms that lead to extinction of light:
Scattering,
Absorption.
Most everyday materials like e.g. colored glasses or transparent colored plastics absorb light, which means that they take some frequencies away, and reflect+transmit the remaining ones, which means that the color you see them have is also the color they turn light into when looked through.
But in the atmosphere, namely the troposphere, the dominant extinction mechanism is scattering, which indeed leads to the scattered light being blue while the transmitted part is orange. In the stratosphere, in addition to Rayleigh scattering by (mostly) nitrogen and oxygen molecules, there's an ozone layer, which makes the light bluer by absorption. This makes the twilight blue instead of sandy-colored that it would have without ozone.
Aside from atmosphere, you can see such scattering extinction in some other materials via the Tyndall effect. E.g. opalescent glass can exhibit this (image from the article linked):
Another example of such behavior is in coated glass, where the coating uses interference of light to enhance transmission of some frequencies or to reflect them efficiently. In particular, you might have noticed that typical medical eyeglasses reflect purplish light when turned into one orientation, and greenish when in another.
The following is multiple choice question (with options) to answer.
Absorbing sunlight causes objects to what? | [
"cool",
"chill",
"freeze",
"blaze up"
] | D | absorbing sunlight causes objects to heat |
OpenBookQA | OpenBookQA-4497 | genetics, vision
Females who are heterozygous for red and green pigment genes that encode three
spectrally distinct photopigments have the potential for enhanced color vision, as they are effectively tetrachromats (Deeb, 2005, Neitz et al., 1991). However, sensitive color-contrast testing on 43 tetrachromats has revealed that most of these females have no deviating color-discrimination whatsoever. 8 subjects showed relatively small effects, while only one showed a clear increased sensitivity in a narrow range of frequencies. It is believed that the human visual system is not plastic enough to cope with the extra spectral input. In fact, in the group there was an overall increase in error rates on some color tests (pseudoisochromatic plates, and Nagel anomaloscope color matching) (Jordan & Mollon, 1993).
In New World Monkeys, however, the situation is different. Squirrel monkeys are basically a dichromatic species, but two-thirds of the females are heterozygous, and gain trichromatic vision by expressing two of three possible alleles coding for pigments in the middle- to long-wave range of the spectrum. X-chromosome inactivation serves to segregate the alternative allelic products in different subsets of cones. The visual system of the heterozygous female is apparently plastic enough to take advantage of the presence of three classes of cone, because heterozygous monkeys have enhanced color selectivity in the red-green range that are impossible for all males and for homozygous females. This advantage perhaps enables the heterozygote to judge better the ripeness of fruit, or to find fruit or conspecifics (Jordan & Mollon, 1993).
Note that the emergence of trichromacy in humans and some other primates was the result of the red/green gene duplication. Trichromacy in primates was evolutionary selected for likely because of the enhanced capability to discern (ripe) fruits (Lucas et al., 2003). It has nothing to do with sex-differences, because not many human females benefit from tetrachromacy in terms of enhanced color vision.
References
- Deeb, Clin Genet (2005); 67: 369–377
- Jordan & Mollon, Vis Res (1993); 33(11): 1495-1508
The following is multiple choice question (with options) to answer.
An attractive woman got her eye color via | [
"recessive emails",
"dominance",
"saliva",
"chromosomes"
] | D | DNA is a vehicle for passing inherited characteristics from parent to offspring |
OpenBookQA | OpenBookQA-4498 | zoology, ornithology, ethology, behaviour
Title: Crow branch pecking behaviour I was walking through a small park when two crows started cawing at me, and followed me, flying from tree-to-tree as I walked. I speculate that this is a territorial or protective behaviour, but what I found different was the crows were violently pecking the branches nearby them. I have no memories coming to mind of seeing this behaviour beforehand. I speculate that this behaviour could be threat displays, but a quick search on Google did not reveal to me any authoritative studies on this phenomenon. I'd appreciate more information and sources.
This question has been added as a casual observation on iNaturalist. This is a good question. This type of behavior -- pecking at a branch, wiping the side of the beak on a branch, pulling off twigs and dropping them, or knocking off pieces of bark -- is quite common among many corvid species, particularly when they are interrupted by something or someone that they might consider a threat. This includes not only potential predators but also potentially hostile conspecifics.
It is typically considered to be a form of displacement behavior. The concept of displacement behavior, from classical ethology, posits that when an animal experiences two conflicting drives to do two different things, it doesn't know which to do and does a third thing instead to dissipate the drive or anxiety. For branch-pecking in crows, see E.g Kilham and Waltermire 1990 Ch. 12.
Referece: Kilham, L., & Waltermire, J. (1990). The American crow and the common raven. Texas A&M University Press.
The following is multiple choice question (with options) to answer.
Robins will often devour | [
"rocks",
"wood",
"glue",
"grasshoppers"
] | D | birds sometimes eat insects |
OpenBookQA | OpenBookQA-4499 | food, decomposition
Title: Worm compost cannot have cooked food I live in the Netherlands and it is getting fashionable to compost with worms. After investigating a few websites I noticed that most websites suggested that I cannot feed the worms leftovers from citrus fruits. This seems logical. I then started noticing that people advise against feeding the worms cooked food.
I'm no biologist but I cannot imagine a reason why cooked food is bad for the worms. Could anybody explain why this might be in layman’s terms? There are a few reasons for not feeding cooked foods to worms (Eisenia spp.) in a smaller household size worm farm. It's not because the food is cooked but what it often contains.
The earthworm used in vermiculture is usually Eisenia fetida (red wigglers) though other Eisenia species are sometimes used. All Eisenia are epigeic species meaning they live in the junction of decomposing organic matter (such as leaf litter, aging manure, rotted fallen trees) and their natural food is decaying plant matter and bacteria that are also digesting the organic matter. They don't make use of small dead animals (meat and fat).
In large scale commercial vermiculture operations, leftover and past-due-date foods from restaurants, institutions, nursing homes and schools are used along with plant matter and carboard and paper. I'm not sure how they balance cooked foods but possibly much less is used than plant matter.
The fact food is cooked isn't the problem but what's in it and/or what happens to it when added to the bin. If you have leftover vegetables and fruit that's been cooked with no added salt, it's perfectly acceptable. A certain amount of sweetened cooked fruit is also fine as the worms will eat that too. But ready-made foods usually have preservatives, salt, fats and spices added. Either worms won't eat it, leading to odour caused by mouldy rotten food, or it can make them unthrifty and even killing off your worms if it's fed them repeatedly.
The following is multiple choice question (with options) to answer.
Which is likely to rot? | [
"flying birds",
"a formerly-living organism",
"compressed oxygen",
"a shiny rock"
] | B | dead organisms rot |
OpenBookQA | OpenBookQA-4500 | formal-grammars
Title: Useless production Kindly consider the following productions. How can I identify a useless production?
S->aS|A|C
A->a
B->aa
C->aCb
Somebody please guide me.
Zulfi. Starting from $S$ it is impossible to generate a sentential form that contains the nonterminal $B$.
This is easy to see since:
$S$ only has productions whose body contain $S$ itself, $A$ or $C$.
$A$ has no nonterminals in the body of its productions.
$C$ has only $C$ itself in the body of its productions.
This means that the production $B \to aa$ is useless.
The following is multiple choice question (with options) to answer.
A producer makes its own: | [
"sustenance",
"air",
"shelter",
"body"
] | A | a producer produces its own food |
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