source string | id string | question string | options list | answer string | reasoning string |
|---|---|---|---|---|---|
OpenBookQA | OpenBookQA-2001 | visible-light, sun, weather
Title: Why are clouds lighter than the sky during the day but darker at night This is probably a very basic question but I couldn't find a good answer to it, most search results are about rain clouds or clouds appearing red at night (something I've never seen except for during sunset but apparently it's common in bigger cities).
Basically what I'm wondering is why clouds during the day appear lighter than the sky (white vs light blue) while clouds at night and during the evening appear darker than the sky (see image).
Image quality is low because I took it with my phone through my window.
I guess the clouds could be blocking the light and therefore appear darker but in that case, shouldn't the same thing be happening during the day? There could be quite a few things going on.
Off the bat there's no incoming light for them to scatter: during the day, clouds are white because the water droplets are big enough for all visible light to cause Mie scattering, but if you don't have much light falling on them, you can't observe the scattering and you can't observe light passing through either.
Then you could consider the fact that in some places, it rains more in the evening/night than during the day (if you have hotter surface temperatures during the afternoon, you see cloud formation and precipitation during the late evening, and with the lower temperatures in the night, the air is more likely to become saturated, see Dew Point), and clouds which precede rain are thicker and denser. They don't allow much light pass through.
And lastly, there's less ambient light which they can reflect back towards you.
The following is multiple choice question (with options) to answer.
A cloud gets fat and heavy and dark. The sky gets darker. The next step to expect is | [
"ice",
"precipitation",
"sunshine",
"flowers"
] | B | water vapor condensing in clouds causes rain |
OpenBookQA | OpenBookQA-2002 | organic-chemistry, physical-chemistry, biochemistry, alcohols
Title: Storage of Urine Not all may be favorable to this project, but I will explain what I am trying to do. I work at home, and instead of walking a moderate distance to the bathroom and loosing my focus, I've been, at times, peeing in a 3 Quart Poland Springs water bottle. If you take offense at this, please do not continue reading except to be helpful in the scientific goal. I know this subject won't suit many types of people, so just ignore it if that is your case.
I noticed first of all that urine is not at all as sterile as people say that it is. The rate of growth of bacteria is relatively slow, but as a precaution, I found the need to use additional measures to prevent the growth of bacteria. I settled on the following method: I have two bottles and I add to each bottle about enough salt as can be soluble in the urine and sometimes maybe a little more. The one bottle then fills up throughout the day and is emptied, washed, and refilled with salt. The salt helps to kill the bacteria which would be lingering in the empty bottle. The next day, the bottle stays empty and the other is used.
I would add that I discovered that the bacteria (without the salt) does not usually grow unless the bottle is left with urine for two days. After this, however, that same bottle (without the salt) would retain the bacteria and immediately grow, if used again.
This system works relatively well, so long as it is done every day. It will even withstand 2 days with only moderate growth. (If I should leave it by mistake for longer it can get ugly). Nevertheless, I am still looking to improve upon this. One reason is that, if I drink less water or relieve myself normally, the bottle does not fill in one day. I am looking for someone with knowledge of chemistry to help me find a substance that can be added to this solution which fits a number of common sense criteria. I will also add a list of the substances that I have tried or already considered.
Necessary qualities
The following is multiple choice question (with options) to answer.
How long might a bear likely to remain its den without eating, drinking, or excreting after November? | [
"The first few weeks of December",
"Until it hears the call of the wild",
"For around twenty weeks",
"until hunters kill it for its pelt"
] | C | hibernation is used for conserving resources by some animals |
OpenBookQA | OpenBookQA-2003 | species-identification, microbiology, microscopy
Title: Identification of protozoa under microscope I observed maybe Protozoa from standing FRESH water and from slowly flowing FRESH water. I am complete dilettante. Can you tell what these creatures are?
https://www.youtube.com/watch?v=6D5ck3zNJzA&t=474s
Thank you.
Added picture for to be more specific At first glance, the organisms may hold the appearance of protozoans like ciliates. However, I am of the belief that these 'totally tubular' micro organisms are in fact diatoms.
The diatoms are a diverse range of eucaryotic microalgae which comprise a large percentage of the phytoplankton group. (Diatomaceous earth is the residual remains of their calcareous walls)
They are likely diatoms because of their apparent hard membrane, and slight brown-green pigment, typical of heterokont diatoms.
I would be unable to specify the organism to family level. However, you may wish to complete your investigation by looking under the order 'Pennales'.
For general information regarding the Diatoms, you may visit https://en.wikipedia.org/wiki/Diatom
Morphology and description available from: https://books.google.co.uk/books?id=xhLJvNa3hw0C&printsec=frontcover&source=gbs_ge_summary_r&cad=0#v=onepage&q&f=false
Good luck
The following is multiple choice question (with options) to answer.
An amoeba is a unique individual that | [
"makes friends",
"has multiple uses",
"works together",
"exists solitary"
] | D | a single-cell organism can survive without the help of other cells |
OpenBookQA | OpenBookQA-2004 | materials
The image is a modified version of an image found at www.geology.um.maine.edu. Original credit: Passchier and Trouw, pg 33 (2005).
The following is multiple choice question (with options) to answer.
Compost, small rocks, and organic material make up | [
"air",
"stone",
"land",
"water"
] | C | a plant requires soil for to grow |
OpenBookQA | OpenBookQA-2005 | mountains, rainfall
Title: Could a waterfall lashing onto a road lead to a landslide? Here is a video of a waterfall lashing on to a mountain road, with vehicles driving under it.
https://youtu.be/cHaguj--YBc
There appears to be a big hole carved out right next to the road, possibly by the force of the waterfall.
Is this a ticking time bomb for a landslide? Potentially, a landslide could occur. Whether it would be a minor slip or a major fall depends on the geological conditions at the site, the force of the water and the duration that the site is impacted by the water.
In the video in question, the rock face above the road appears competent, but there are not guarantees. The main issue would be is the water undermining the road which could cause a slip and the road to slide.
The more loose the geological material is, the easier it is to dislodge it. Once one item moves a chain of events can occur where additional items are dislodged and a slide occurs.
In addition to high pressure water dislodging material, water acts as a lubricant, making it easier for rocks and regolith to be dislodged.
To minimise the potential for a slide to occur in such a situation, the surface of the road would need to be sealed very well and a very good drainage system installed that would move the water away from the road and the slope below the road
The following is multiple choice question (with options) to answer.
Rain and what cause erosion? | [
"wind vanes",
"sunlight",
"concrete",
"drafts"
] | D | wind and rain cause erosion |
OpenBookQA | OpenBookQA-2006 | 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 cow eats some hay, an apple and a piece of bread. In its tummy | [
"the food rots",
"the food dissolves",
"the food melts",
"the food grows"
] | B | the digestive system breaks food into nutrients for the body |
OpenBookQA | OpenBookQA-2007 | the-sun, orbit, planet, earth
Is the spiraling movement caused by sun movement (on its path shown
above) where the sun is dragging the earth (and other planets)?
No, the Sun's and the Earth's mutual gravity cause the Earth to rotate around the Sun. The Milky Way's gravity causes our Solar System to revolve around the galactic center. The Sun and the Earth are on the same plane and moving through the galaxy together. The Earth would still rotate around the center of the Milky Way if the Sun magically disappeared.
Does the earth go in front of the sun then back, then fourth and back
like it is shown on the video? I see both the sun and earth racing
with each overtaking the other over and over. Is this assumption true?
In this manner, would earth, at one point in time, be closer to the
destination where the solar system is heading (I think they call the
destination Vega) than the sun?
If you consider a plane tangent to the Sun's velocity vector, then the Earth will pass across that plane twice per year, appearing "in front of" and then "behind" the Sun. This is simply a geometric result since the Earth and Sun share another plane. I wouldn't call any future position of the Solar System a "destination" without evidence the Solar System was sentient, but I am not a philosopher.
I am working on a poetry piece. If I mention that earth and sun are
locked in a never ending race with each taking the lead (earth moving
in front of the sun's path / winning) and earth actually dropping out
of the race (spiraling/moving out the race and falling behind), that
they are destined to never meet (collide), would I be correct?
We haven't ruled out the possibility that the Sun may someday envelope the Earth: What will "the Earth being consumed by the Sun" look like?. Also, the Earth isn't likely to leave its orbit before that time, but the Solar System is chaotic on long time scales. However, your poem would be consistent with current models, and we (humans) don't conclusively know how the Solar System will end. So my two cents is that your poem doesn't contradict modern astronomy. Besides, what's the use of a poetic license if you don't use it?
The following is multiple choice question (with options) to answer.
the Earth rotating on its axis causes the sun to appear to move across the sky during what? | [
"dark hours",
"sunlight deficient",
"night",
"waking hours"
] | D | the Earth rotating on its axis causes the sun to appear to move across the sky during the day |
OpenBookQA | OpenBookQA-2008 | photosynthesis, respiration, ecosystem, decomposition
Maybe you should study the metabolic processes of plants and life in general to better understand this. All life consists of chemical reactions that build up structures; in order to build them up you need energy (because of the second law of thermodynamics), and all living things create that energy by breaking down complex molecules into simpler ones. (as such it would be more accurate to say that all life consists of chemical reactions that build up and break down various structures). You might be wondering "but what about the difference between autotrophs and heterotrophs I heard about"; the difference between those is where they get the complex molecules from in the first place. Autotrophs use a different source of energy to build them up while heterotrophs get them from their environment. As such, you can think of every living thing as being made of two kind of molecules: those that actually form their structure (in humans, the molecules that make up cell membranes, bones, muscles, etc) and those that are stored in order to be broken down to power the whole system (in humans that's fat, glycogen, glucose, etc). Of course a molecule can do both; if you're starving your body may start to break down structural molecules for power. There are many different ways of breaking down those big molecules for power; the most efficient one, that starts with a big chain of carbon atoms and cuts it down into individual CO2 molecules using O2 molecules, is called aerobic respiration (i.e. respiration that uses oxygen).
Because those complex molecules are required to power all life, autotrophs (the organisms that actually make them) are very important, and the processes they use to make them are very important too. The process that makes almost all of the molecules that power almost all life on earth is photosynthesis, which uses the energy from the sun to power a reaction that converts CO2 from the atmosphere into big carbon-based molecules we'll call carbohydrates. This is called "fixing carbon", since the carbon atom is the most important one; measuring how much photosynthesis is happening is another way of measuring how many carbon atoms move from being part of a CO2 molecule to being part of a plant.
The following is multiple choice question (with options) to answer.
In the photosynthesis process what has the role of raw material? | [
"water",
"CO2",
"wind",
"dirt"
] | B | In the photosynthesis process carbon dioxide has the role of raw material |
OpenBookQA | OpenBookQA-2009 | arduino, mobile-robot, wheeled-robot, micromouse
Title: Looking for a cheap(ish) micromouse that I can program with C/C++ I'm looking to buy a micromouse (i.e. a small single-board unit with wheels and IR sensors that can move around freely). I've done a lot of searching but have only found resources relating to building one from components bought separately. However, I'm more of a programmer than an electrician so I fear I would struggle with this.
Anybody know where to buy one of these in the UK? (PICAXE does some suitable stuff but they're BASIC only unfortunately). My budget is about £60. Try a Pololu 3Pi. They were going for 50usd during black friday. Normally $99. You can use arduino IDE to program it using Wiring, a C/C++ like language.
You would probably have to add IR sensors yourself, either via the expansion board, or re-wire the existing line detectors
At the moment, Hobby Robots are still only reachable by those with soldering skills. But that will be changing in the next few years.
The following is multiple choice question (with options) to answer.
A mouse is made up of | [
"straw",
"organic material",
"dairy",
"buttons"
] | B | an organism is a source of organic material |
OpenBookQA | OpenBookQA-2010 | telescope, mars
Have a look at this guide explaining how consumer-grade computer webcams can be used. It contains a neat comparison of a single frame and a stacked image.
Please note that I'm merely speculating as to which techiniques could be used to obtain such images. I can see that the author posted their email on the S&T site and that there's a comments section as well. Feel free to ask them yourself.
The following is multiple choice question (with options) to answer.
Cameras reflect | [
"a persona",
"good decisions",
"UV rays",
"the stars"
] | C | tinted lenses reflect ultraviolet rays |
OpenBookQA | OpenBookQA-2011 | zoology
Title: What is the reason for cats not liking water? I have two cats myself, a Siberian and a Maine Coon, neither of which like water. In fact, they detest it - like most cats. I was wondering what the reason for this was and if any of you have any interesting theories as to why this is the case.
Thanks in advance! First, some cats do like water. But it seems true (from personal observation and most people's opinion) that most cats don't.
The question has already been asked many times online. Just Google your question!
I doubt one will find peer-reviewed papers on the question but below is a summary of what seem to be the most often mentioned possible reasons I could find. Of course, these bullet points are very hypothetical and I don't know of any research presenting evidence for or against these hypotheses.
Their fur is not really adapted for the water and will very quickly become waterlogged and heavy making it uncomfortable.
Cats are generally speaking quite skittish
Cats may not like the odour of chemicals we put in the water.
Cats love to groom themselves. It is an aweful lot of work to do the grooming after a bath.
Note also that domestic cats are descendent from cats living in very arid areas. The most closely related species with cats are the African Wildcat living in Northern Africa, the Near East and around the periphery of the Arabian Peninsula.
Source
My non-peer reviewed sources are
http://www.petful.com/behaviors/why-do-cats-hate-water/
http://www.animalplanet.com/pets/healthy-pets/do-cats-really-hate-water/
http://www.petguide.com/blog/cat/why-do-cats-hate-water/
The following is multiple choice question (with options) to answer.
A cat is shown that food is placed on a high surface. The cat needs to eat the food to live, so the cat | [
"learns to wear clothes",
"learns to eat bees",
"learns to jump higher",
"learns to cook food"
] | C | adaptation is when an organism develops a trait over time for survival |
OpenBookQA | OpenBookQA-2012 | species-identification
Title: What is this plant with purple berries? This plant was seen by a friend of mine in Virginia. What is it? It looks to me like beautyberry. Here is a link to a species page to judge for yourself. It's a very common cultivar and I've heard of people using it to control garden pests.
http://uswildflowers.com/detail.php?SName=Callicarpa%20americana
Here is an image of American Beautyberry from gardenknowhow.
It is often confused with Japanese Beautyberry which has smaller berries on stalks.
The following is multiple choice question (with options) to answer.
Plants can use what as a pollinator? | [
"bees wax",
"small extinct birds",
"rhinos",
"windy air"
] | D | pollination is when wind carry pollen from one flower to another flower |
OpenBookQA | OpenBookQA-2013 | Best Japanese Brown Rice, Air Fryer Burgers And Fries, østfold University College Vacancies, Band T-shirts Walmart, How To Become An Anglican Priest, Too Much Fennel Taste, Porter Cable Circular Saw Cordless, Utmb My Chart, Iams Large Breed Dog Food Nutrition Facts,
The following is multiple choice question (with options) to answer.
The national symbol for the US would most likely eat | [
"roaches",
"birds",
"mosquitoes",
"salmon"
] | D | eagles eat fish |
OpenBookQA | OpenBookQA-2014 | zoology, species-identification, ornithology, behaviour
Title: What is this crow eating, and is it a common part of the corvid diet? Here's a picture (by Rob Curtis) of a crow carrying and eating the corpse of what looks a bit like a small hawk or falcon:
Other pictures clearly show the crow is eating the dead bird. This image shows the underside of the head and beak; this one shows its legs, which are grayish.
What bird is being eaten?
Is this bird a usual part of the corvid diet? Or did the crow just opportunistically scavenge a dead bird? Crows are omnivorous, and will eat almost anything they find or can kill.
In this case the prey looks like a Yellow-Shafted Flicker.
The following is multiple choice question (with options) to answer.
What is used to catch prey by some birds? | [
"a bill",
"fire",
"nets",
"cups"
] | A | a beak is used for catching prey by some birds |
OpenBookQA | OpenBookQA-2015 | zoology, ethology, learning
Title: How do beavers learn how to build dams? I was wondering whether all beavers, from all around the world, know how to build dams and lodges? Do they need to learn it from their parents? If you release a group of beavers in the wild that haven't been in contact with their parents, would they start to build stuff? or just hopelessly die/starve to death? Question summary: is dam building learned or instinctive in beavers?
A blog post from 2011 references an article in the Juneau Empire titled Running water is sound of spring for beavers. This article is no longer hosted on the Juneau Empire website, but archived versions are available.
Here's an excerpt (emphasis mine) --
Swedish biologist Lars Wilsson spent years studying captive and wild beavers, and he gained remarkable insights into their behavior. He raised beavers in an outdoor enclosure and in a large indoor terrarium ...
Wilsson initially captured four adult beavers and later he raised a number of beavers from infancy, some in small colonies with their parents and some completely isolated from adult beavers. He isolated the young beavers to see what beavers learn from their parents and what behaviors are instinctive.
He found that young beavers - who had never even seen a beaver dam - were able to build almost-perfect dams at the first opportunity.
The foundation of sticks and logs anchored to the stream bottom, the interwoven lattice of trimmed branches, the mud chinking, every aspect of dam building was hard-wired. Beavers do get more skilled at dam building as they gain experience, but the building behavior is instinctive.
Wilsson learned that the sound of running water is the cue for dam building and dam repair. In one experiment, he played a recording of running water, and the young beavers built a dam in a tank of still water in the terrarium. In another peculiar experiment, his captive beavers built a "dam" on a concrete floor against a loudspeaker that played the sound of running water.
The following is multiple choice question (with options) to answer.
If you build it they will come also works for aquatic animals, as when there is more water: | [
"there are less aquatic animals",
"they increase with human intervention",
"their numbers will increase",
"they will remain stagnant"
] | C | as water increases in an environment , the population of aquatic animals will increase |
OpenBookQA | OpenBookQA-2016 | 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 plot of land a thousand miles wide has water, food, shelter, clean air and a good climate, then | [
"organisms will struggle with it",
"organisms will populate it",
"organisms will die off",
"organisms will avoid it"
] | B | as available resources increases , the population of an organism that uses those resources will increase |
OpenBookQA | OpenBookQA-2017 | entomology
Title: What is the name of this tiny creature? It looks like a tiny piece of moving cotton? By chance, I saw this tiny insect on my bag a few days ago in Sydney. Am I the first person who has pinpointed this animal?! If not can you please let me know its name? From your image, it looks like it might be a woolly aphid. I just did a bit of cursory research, and it looks like they're often described as floating pieces of fluff, that seem to wander instead of directly heading somewhere. The fluff on their back is actually wax produced as a defense mechanism from predators and the like. I hope this is what you were looking for!
The following is multiple choice question (with options) to answer.
What would a fly find most compelling? | [
"a science fiction movie starring the actor Jeff Goldblum",
"a toilet seat scrubbed with baking soda and vinegar",
"a saline solution for contact lenses",
"a steak forgotten on a counter for an entire day"
] | D | the smell of rotting meat attracts flies |
OpenBookQA | OpenBookQA-2018 | quantum-mechanics, operators, measurement-problem, eigenvalue, observables
If you measure the length of a piece of paper with a ruler for example, you will not obtain a different result when you measure it again.
When you now measure a quantum system, you have two types of statistics in there. First, your particle exhibits certain probabilities to be at a certain location. Secondly, your measurement apparatus is never 100% precise. The best you can do is perform lots of different measurements of identically prepared systems which is also a source of uncertainty because identical preparation might be difficult in real life. You will obtain the probability of presence of the particle at a certain position. But since the position is a continuous variable, there will always be an error. You can never measure "true values" but you will not be "limited by the collapsed state" as you formulated it.
The following is multiple choice question (with options) to answer.
With a ruler I can measure | [
"feelings",
"love",
"air",
"a phone"
] | D | a ruler is used for measuring the length of an object |
OpenBookQA | OpenBookQA-2019 | thermodynamics, water, phase-transition, phase-diagram
Title: Vaporization - phase diagram I understand what boiling and vaporization is. But what puzzles me is the phase diagram.
When I spill a glass of water in my room, it will soon vaporize, though there was normal atmospheric pressure and 20 °C. If you look in phase diagram of water, it should be still liquid at this point.
I understand that molecules of water escape the surface and turn into vapor, but... is the phase diagram of water wrong then? The temperature and pressure didn't change around that spilled water and still it turns into gas, although (looking at the phase diagram), it should be liquid. The phase diagram has equilibrium states for pure water, vapor, and both at saturation. You have water exposed to atmospheric gases, so the pressure is not that of pure vapor. The water will evaporate trying to create a partial pressure of vapor equal to the vapor pressure for saturated water at the water temperature. If the surface is open to flow of fresh air, this vapor pressure is not achieved, and the water slowly evaporates away.
The following is multiple choice question (with options) to answer.
The four stages of the water cycle are evaporation, condensation, precipitation, and collection. What happens after the last step of this cycle, and all cycles? | [
"explosion",
"a new step",
"it repeats",
"it ends"
] | C | a cycle happens repeatedly |
OpenBookQA | OpenBookQA-2020 | electric-circuits, electric-current, electrical-resistance, batteries, short-circuits
Title: The importance and the role of a switch in an electrical circuit There is this simple test:
Three identical bulbs are connected in the circuit illustrated in the figure. When switch $S$ is closed:
a] The brightness of $A$ and $B$ remains the same, while $C$ goes out.
b] The brightness of $A$ and $B$ remains the same, while that of $C$ is halved.
c] The brightness of $A$ and $B$ decreases while $C$ goes off.
d] The brightness of $A$ and $B$ increases while $C$ goes off.
For my opinion the answer to this question is D because the switch (which has a resistance of $0\, \Omega$ has a node connected before the third bulb C) that "interrupts" the circuit. But, going into detail, according to Kirchhoff's first law the current should also go on the third bulb as in the first red node it divides into two currents $I_1$ and $I_2$. The current $I_1$ goes for example in the key $S$ and $I_2$ in the third bulb. The key and the third bulb have the same potential difference. I believe that the current $I_2$ passes through the third bulb but the current passing through it is so small that it does not turn on.
I made a point. When an individual is operated on at the heart and puts a by-pass (a bridge), blood will flow on the tube that detects the by-pass and the occluded artery (the third bulb) where blood will flow slowly, over time it will atrophy.
If the circuit were like the one drawn in the picture I would answer the b).
My question is: I have not very clear the rule of a switch in a eletric-circuit.
In fact, I find it difficult to give an answer to the following image.
The following is multiple choice question (with options) to answer.
A light is turned on and the circuit is closed so | [
"the house is old",
"the connections get warm",
"the light is off",
"the light is broken"
] | B | electrical current running through a wire causes that wire to heat up |
OpenBookQA | OpenBookQA-2021 | air-pollution
Title: Less pollution: moving hurricane debris to other regions for use, or burning? When a big hurricane hits, it can create debris on the scale of $\mathrm{10^8 yd^3}$. Cities in Florida, Texas, and other affected areas are struggling to hire enough trucks and drivers to pick it up quickly. But aside from that, I noticed many of the areas have started to burn the debris once it starts building up.
Got to wondering... typically mulch comes in modestly pricey, and when free mulch is offered, it often goes quickly.
So assuming a fair portion of debris is mulchable and is of interest to other areas, and that we can acquire typical transportation resources, then we'll set up transfer from collection sites to those other regions rather than burning it. What would be the net pollution result?
If removed for mulch and such: trucking pollution + decomposition (- trees saved locally??)
If burned: the burning pollution.
Obviously it's about approximation rather than exacts, it's probably hard to appraise the different byproducts from burning versus decomposition, and a lot probably depends upon the way it is burned. But as a whole, can we get a rough estimate of comparable quantities/damage done... is it less pollution/damage even to truck it an average of 3000 miles? 1000 miles? 100 miles? 10 miles? Should it be burned on the spot (if done safely)? Would think there's got to be some way to get a very rough idea.
Certainly the best option if viable might be leaving it in place to decompose. But considering how upset people are getting at having debris around these parts a month later, exclude that option from the possibilities.
Trucking or burning, how do they compare? As the question was changed, my answer attempts to evaluate only the difference between burning and transporting. Please correct my values if my quickly found sources are inaccurate or you find more representing. I know there is quite a few unwritten assumptions that simplify this problem.
The following is multiple choice question (with options) to answer.
An industry that create a lot of waste is: | [
"Solar Power Companies",
"Recycling companies",
"water production companies",
"Cleaning Companies"
] | D | processes sometimes produce waste products |
OpenBookQA | OpenBookQA-2022 | entomology, habitat
Title: Do hornets return to the same nest after winter each year? I have what I think is a hornet nest on the soffit of my house.
The nest has been removed, however, the hornets keep rebuilding. Also, they have started to swarm the sewer vent pipe (not shown in photo).
If fail to get rid of the hornets this fall, will they return to the same nest next year (or overwinter and continue to live there)?
I'm not sure if this is relevant or not:
To give you an idea of what kind of winters I am dealing with, I am near Toronto, Ontario; the temperature goes down to -25 degrees Celsius.
If fail to get rid of the hornets this fall, will they return to the same nest next year (or overwinter and continue to live there)?
No. The nest, likely made of wood pulp (and maybe mud), will/should degenerate to unusable over the winter, though the bulk could remain for a couple of years. All wasps die, except for the new queens (fertile, mated females) who overwinter in sheltered crevices somewhere.
In spring, it is a single wasp that starts a hive: the new queen. She builds a new, small hive in which to lay eggs, which is added to initially by the queen and then by workers who have hatched.
While she will not return to an old hive, the conditions which appeared advantageous to one queen (shelter from rain, intense sunlight, winds, etc.) will also seem advantageous to other queens, which is why nests appear in the same places year after year.
Edited to add: It appears most likely that the queens that overwinter are "new queens", that is, mated female offspring of the queen. H/T @Brian Krause.
The following is multiple choice question (with options) to answer.
A bird can be saved in a harsh winter if it is driven to locate a | [
"long metal rod",
"small tiger sanctuary",
"stocked provisions",
"easy dial phone"
] | C | feeders attract animals to a location |
OpenBookQA | OpenBookQA-2023 | species-identification, ornithology
Title: Help me find out what this bird is (description, no picture) A while ago I read about this bird(s) whose species status was not confirmed. This was because they had a very large distribution and birds in adjacent population could breed with each other but birds at each end of the distribution (western Europe and South Asia I think) couldn't. I am pretty sure that they were some kind of gull and from Europe to Asia their wings got lighter, from black to grey. I think I might have read about them in a Richard Dawkins book.
Does anyone know the species I'm talking about? You're describing a Ring Species: "a connected series of neighbouring populations, each of which can interbreed with closely sited related populations, but for which there exist at least two "end" populations in the series, which are too distantly related to interbreed, though there is a potential gene flow between each "linked" population".
The classic ring species is the Herring Gull complex, and that's probably what you read about:
The classical example of the ring species model was originally based upon the herring gull complex (Mayr 1942). This group comprises more than 20 taxa of large gulls (Haffer 1982) which together occupy a circumpolar breeding range in the northern hemisphere. ... Mayr envisioned all taxa of the circumpolar chain to be connected by gene flow, while herring and lesser black-backed gulls in Europe, the hypothetical endpoints of the ring, have reached full reproductive isolation and now coexist as distinct species.
--The Herring Gull Complex (Larus argentatus - fuscus - cachinnans) as a Model Group for Recent Holarctic Vertebrate Radiations
However, recent genetic work shows that the situation is even more complicated than this, and it's questionable whether they really are "ring species":
Contrary to the ring-species model, we find no genetic evidence for a closure of the circumpolar ring through colonization of Europe by North American herring gulls. However, closure of the ring in the opposite direction may be imminent, with lesser black-backed gulls about to colonize North America.
--The herring gull complex is not a ring species.
The following is multiple choice question (with options) to answer.
Humming birds may help the growth of | [
"cars",
"buildings",
"ants",
"tulips"
] | D | An example of seed dispersal is animals eating seeds |
OpenBookQA | OpenBookQA-2024 | electric-circuits, electric-current
Title: Path Of Current In A Wire Why does current follow the path of least resistance? Will all current pass through a wire with $0$ resistance in a junction leaving other resistive wires with no current?
Why does current follow the path of least resistance?
Current doesn't follow the path of least resistance. Please forget that you ever heard that and if you hear someone else say that, respond with something like this:
If there are two parallel connected resistors with resistance $R_1$ and $R_2$ respectively, the current divides between the two paths such that the path with smallest resistance has largest current through.
This is simply due to Ohm's law and, in particular, the fact that parallel connected circuit elements have identical voltage across (by definition!).
With voltage $V$ across, the current through each resistor is given by Ohm's law:
$$I_1 = \frac{V}{R_1}$$
$$I_2 = \frac{V}{R_2}$$
and now it's clear that the smaller resistance has the largest current through. Denoting the total current $I = I_1 + I_2$, we easily derive the current division formula:
$$I_1 = I\frac{R_2}{R_1 + R_2}$$
$$I_2 = I\frac{R_1}{R_1 + R_2}$$
which again shows that the smaller resistance has the largest current through. Note that if (just) one of the resistances is zero, then all of the current is through the zero ohm resistor. For example, if $R_1 = 0$ then
$$I_1 = I\frac{R_2}{0 + R_2} = I$$
The following is multiple choice question (with options) to answer.
If an electric circuit has six paths and another electric circuit has one path, the six path circuit is | [
"really broken",
"singular",
"equidistant",
"slowly burning"
] | C | if electricity flows along more than one pathway then the circuit is parallel |
OpenBookQA | OpenBookQA-2025 | species-identification, botany, ecology
Title: Algae or Lichen identification. Coastal BC, Canada I have tried all books and internet resources I know of, but I still have no idea what this might be — a lichen or something else.
At first glimpse, I thought it was something man-made and unnatural, but then I looked closer and saw how it appears to be attached and growing. It grows on exposed rocks well above the high tide. The photo is taken in late March, on northern Vancouver Island. It's loosely attached to the rock.
It was somewhat abundant around the general area (within of a few km), but I haven't seen it elsewhere - although I'm not from BC so there might be a lot of this around.
The water droplet in the lower right corner give a rough sense of scale.
Edit:
Adding another photo in which I just noticed a streak of white, which I included in original resolution. I want to propose you expand your search to a broader taxonomic scope. Specifically, I think you might be looking at a species of "red" green algae (family: Trentepohliaceae).
From Nelson et al. (2011):
All Trentepohliaceae have filamentous growth forms and often contain large amounts of carotenoid pigments (ß-carotene and hematochrome), causing the algae to appear yellow orange in color (Thompson and Wujek 1997, Lo´pez-Bautista et al. 2002).
The Trentepohliaceae contains five genera: (Trentepohlia, Printzina, Phycopeltis, Cephaleuros and Stomatochroon) and 70+ species worldwide.
For example, the following algae (picture from England) looks fairly similar to your specimen:
Trentepohlia aurea
Source: David Fenwick
If your specimen is a species in this family of algae, it is most likely in the Trentepohlia genus (or possibly Printzina genus).
Trentepohlia is a genus of filamentous chlorophyte green algae in the family Trentepohliaceae.
Typically orange or yellow in color.
Live on tree trunks and wet rocks or symbiotically in lichens.
Here's a picture of a free-living Trentepohlia species from coastal Oregon, USA:
Source: Richard C. Hoyer (2015)
The following is multiple choice question (with options) to answer.
A coral plant will thrive in | [
"depths",
"jungles",
"arctic",
"shallows"
] | D | usually coral lives in warm water |
OpenBookQA | OpenBookQA-2026 | visible-light, sun, weather
Title: Why are clouds lighter than the sky during the day but darker at night This is probably a very basic question but I couldn't find a good answer to it, most search results are about rain clouds or clouds appearing red at night (something I've never seen except for during sunset but apparently it's common in bigger cities).
Basically what I'm wondering is why clouds during the day appear lighter than the sky (white vs light blue) while clouds at night and during the evening appear darker than the sky (see image).
Image quality is low because I took it with my phone through my window.
I guess the clouds could be blocking the light and therefore appear darker but in that case, shouldn't the same thing be happening during the day? There could be quite a few things going on.
Off the bat there's no incoming light for them to scatter: during the day, clouds are white because the water droplets are big enough for all visible light to cause Mie scattering, but if you don't have much light falling on them, you can't observe the scattering and you can't observe light passing through either.
Then you could consider the fact that in some places, it rains more in the evening/night than during the day (if you have hotter surface temperatures during the afternoon, you see cloud formation and precipitation during the late evening, and with the lower temperatures in the night, the air is more likely to become saturated, see Dew Point), and clouds which precede rain are thicker and denser. They don't allow much light pass through.
And lastly, there's less ambient light which they can reflect back towards you.
The following is multiple choice question (with options) to answer.
On a cloudy day | [
"the rain is invisible",
"the clouds are gone",
"the sky is more blue",
"the sun is less visible"
] | D | cloudy means the presence of clouds in the sky |
OpenBookQA | OpenBookQA-2027 | evolution, zoology, taxonomy, phylogenetics
The apomorphy that defines the tetrapods is "paired limbs". You have Amphibia to the left and Amniota to the right, whose apomorphy is " egg with extraembrionic membranes". Inside them, you have Reptilia, whose apomorphies are "skull with upper and lower fenestra and beta-keratin in epidermis". Turtles came from an ancestor with these characteristics. So, turtles belong to the monophyletic group of "Reptiles".
Post scriptum: You wrote that "turtles (specifically sea turtles) live on both land and water, very much like amphibians". Just a curiosity: the reason why sea turtles leave the water (sea) from time to time shows exactly that they are not amphibians! Amphibians, being non-amniotes, have eggs that survive under water (actually, with few exceptions, they need to be under water). Turtles, on the other hand, are amniotes, and the amniotic egg cannot be laid under water. That's why the turtles have to leave the water to lay eggs: because, contrary to the amphibians, they cannot lay eggs under water.
The following is multiple choice question (with options) to answer.
Amphibians such as frogs start their lives in eggs in | [
"the pond out front",
"in a camp fire",
"in the turn of the air",
"dark under belly of grass"
] | A | amphibians hatch from eggs |
OpenBookQA | OpenBookQA-2028 | organic-chemistry, everyday-chemistry, experimental-chemistry, biochemistry, food-chemistry
Title: How Bread is made with yeast, sugar and luke warm milk? Materials and Apparatus:
wheat flour
sugar
dry yeast
glass bowl
covering plate
milk
Procedure:
Lukewarm milk is taken in the glass bowl and sugar is added to it. Then, yeast is added to the same.
The mixture is left undisturbed for 10-12 minutes to activate the yeast
3 cups of wheat flour are added to the bowl containing the milk mixture.
The mixture is mixed thoroughly with 100ml of added water and the dough is kneaded well
The dough is placed in a bowl, covered with a plate and left undisturbed for 2 hours.
My query/confusion:
Why is milk needed?
"activated yeast"- what's the difference?
Can yeast work without sugar or milk.
Detail out the stages of the anaerobic oxidative process which takes place as a common first step in both aerobic and anaerobic respiration.
Finally, feel free to share anything I may be missing which should be here.
If you have any confusion regarding what I want to ask, please ask in the comments. Please upvote if you are curious about it too
milk is not needed, 'pure' bread is without milk
yeast is a fungus, therefore, it is alive. Its best to work with fresh yeast, which you find as small cubes in the refrigerated section. This one does not have to be activated. non-fresh yeast is dried, so in order for it to work properly, it has to be undried by adding water, which is called activation.
and 4. As said before, milk is not needed. Sugar however is the food for the yeast, without it, it does nothing. In aerobic breathing, the yeast metabolizes the sugar as we would: sugar + oxygen -> water + CO2. Without oxygen, the yeast resorts to ethanol fermentation: sugar -> alcohol + CO2 (this is, why it is used to make beer or wine). For making bread, we have a mixture of both respirations, which does not really matter, since we are only interested in the CO2, which makes the dough fluffy =) But without sugar, there is no CO2.
The following is multiple choice question (with options) to answer.
Toasting already-baked bread requires using | [
"unprocessed gluten mix",
"a thermal conductor",
"a snowboard",
"an energetic stream"
] | B | a thermal energy conductor transfers heat from hotter objects to cooler objects |
OpenBookQA | OpenBookQA-2029 | electricity
Title: Can touching a single power line (on the street) kill you? Statement: You need to touch two power lines at the same time to get electrocuted. I am kinda doubting this now because, in the video linked below, it looks like the person is only touching one line but still gets an electric shock. Is this possible? and also the person is on a tree and aren't trees insulators? This video isn't sensitive or anything, it actually funny, so please don't hesitate to watch. Thanks!
Video Unless there is sufficient insulation (electrical impedance) between you and the earth when you touch a high voltage wire, yes you may get electrocuted. This is because most electrical power systems in the world are earth grounded (referenced to earth). The higher the voltage the greater the impedance to between you and earth ground needs to be. At 60 Hz it only takes 50-100 mA of current in a path through the heart to cause ventricular fibrillation.
If you are isolated from ground and touching two wires with your bare hands, electrocution is possible if the voltage difference has the potential to cause a lethal electric shock and the insulation on the conductors is insufficient to limit the current to below the threshold for a lethal electric shock.
oh okay, bats die when they hang on the cables, but they do not
provide any connection between live and ground, how is this possible?
Regarding your above comment to Solar Mike, it is ONLY possible for the bat to be electrocuted if the bat is simultaneously in contact with the high voltage wire and another wire or grounded object where the voltage between them has the potential to cause a lethal electric shock.
Bats are physically different than the typical birds you observe on HV wires. For one I understand they may have wingspans much larger than ordinary birds. So if they are on a HV wire and spread their wings, there is a higher likelihood that their wings will simultaneously contact more than one HV wire at a time, or some grounded part, causing lethal electric shock. Regardless of the reason for their deaths, they must simultaneously be in contact with two conductors with a potential difference capable of causing a lethal electric shock.
Hope this helps
The following is multiple choice question (with options) to answer.
A person can be punched in the chest without the heart stopping because | [
"muscles crumple",
"ribs guard it",
"hearts are stone",
"hearts are hollow"
] | B | the skeletal system protects internal organs |
OpenBookQA | OpenBookQA-2030 | classical-mechanics, energy, electricity
Title: Can we imagine having a computer keyboard that recharges itself through mechanical utilization? Silly question here.
I have a debate with my father, and while I am decent at high school level physics, both he and I cannot determinate through calculus which of us is wrong.
Basically, he had the idea that perhaps, through simple mechanical utilization, a wireless keyboard can be charged and used, without any other energy source. (The keyboard can have a battery that can be recharged through the said mechanical utilization though), I have the intuition that the idea is interesting, but physically problematic.
With simple research, I have seen that an idle keyboard has a consumption of $1W$, and a used keyboard will use between $1.5$ and $2.5W$.
So, we have specific questions:
Is collecting the mechanical energy from the keyboard doable ?
And if yes, how much energy can typing on a keyboard's key produce ?
How it may impact the overall comfort of the user ?
I have multiple difficulties to answer these myself. How can I know how much a person can generate through typing, how much energy will be lost in the process of using a battery, etc..?
(This is not a concept that I try to sell or anything, this is a mere thought experiment that I wanted to share and resolve, please do not take it too seriously) What you are looking for is fairly simple. All you need to do is build a piezoelectric generator under each key. These generate electricity with each push. With this the element is stretched or vibrated with each push and this generates electricity. Do a Google search and you will find much more.
The following is multiple choice question (with options) to answer.
You can recharge your iPhone by using | [
"ice cubes",
"money",
"wind",
"frozen apple farts"
] | C | wind is a source of energy |
OpenBookQA | OpenBookQA-2031 | power-engineering
Title: Why are hydropower plants always wheel-shaped and not flat? Question:
Why are there no flat power generators like in the picture below, that work on the surface of shallow, but steadily flowing rivers ? (As a floating micropower plant.)
The picture shows a conveyer belt with vanes/blades(?) attached to it. The water flow moves the conveyer belt. A generator could be attached to the front and back "wheel" of the belt.
Here's a video of something similar. I would just build it on a larger river.
Why would I ask this?
There are much more flat rivers than waterfall-like structures on this planet. Using them looks like a much more non-nature-inversive, cheap solution. Having a longer surface should supply better drag by flowing water. When you want to solve a problem, the best start is to look at previous attempts. To provide some perspective, I'm doing that for you now. You are not looking at a typical hydro power plant where a dam provides a high head, and the flow is ducted onto a a francis or pelton turbine. You are describing a microhydropower installation with a floating turbine.
Floating hydrpower allows capturing some power without building a dam. The turbine could be placed in or near the middle of the river, where the current is fastest. An installation with a damn will always harvest vastly more power from the same river.
Before electrical power transmission became widespread, there used to be boat mills - workshops with machinery driven by water wheels, placed on boats.
(Boat mill in Servia, 1900, Image from lowtechmagazine page on boat mills)
Improvised versions have also been used for electricity generation.
Floating hydro power is, AFAICT, an ongoing area of developement. The two most common turbine shapes appear to be a propeller hanging from buoys:
(Image source)
... Or some sort of flat paddle wheel:
Vertical axis turbines also exist.
I think Kamran explains quite well why a propeller or a paddle wheel is used, rather than a conveyor belt. I will just add this: Look at the water wheel in the direction of flow: You want to maximise area here.
The following is multiple choice question (with options) to answer.
An early example of harnessing wind power would be | [
"unicorns",
"santas flying reindeer",
"trumps windy speeches",
"cloth on masts"
] | D | wind is a source of energy |
OpenBookQA | OpenBookQA-2032 | sun
Title: Is there an instance where the sun sets or rises partly, then return back? I am reading Longest Sunset from XKCD. At first, I've thought that he mentions these phenomena just for fun, but it turns out to me that it might happens, based on the level of somewhat seriousness that I perceive from his writing. He doesn't talk about that in detail.
For the sunset:
Sunset starts the instant the Sun touches the horizon, and ends when it disappears completely. If the Sun touches the horizon and then lifts back up, the sunset is disqualified.
I'm not sure if the sunset is disqualified is because it happens, but we don't count it, or because he's just making fun. But I can't prove that this cannot happen. The more we head to the poles, the shorter the night is. Ultimately there will be a point that the sun still sets, but not completely, right?
For the sunrise:
For the purposes of our question, this is not a sunset:
The phrase for our purposes strengthen my doubt that he is being serious. The logic is the same above.
But these two illustrations are in the series of other apparently amusing ones, which are the sun as the cell in division, or as the egg in hatching (if you read the book, you will see this effect stronger).
So, is there an instance where the sun sets or rises partly, then return back? Yes, such sunrises happens every year at the beginning and end of the polar nights at high latitudes. One can have a few days with a glimpse of the sun but disqualified sunsets and sunrises.
Sunsets occur at the end of the midnight sun period by the end of the summer, the first sunset is not complete.
Sun at it's highest elevation at midday. (To be honest, the picture might be taken the day after the first sunrise, as some mountains are hiding the horizon.)
Here is e.g. an article from Svalbardsposten, the northernmost newspaper in the world, reporting of the first rays of sunlight after the polar night and some pictures from the last sunrise/sunset before the polar night in northern Sweden.
The same occurs at the southern polar circle and south thereof, unless it's cloudy...
Update: here is a great time laps from Davis Station in the Vestfold Hills showing exactly what you asked about: Mid winter
The following is multiple choice question (with options) to answer.
The sun setting occurs | [
"30 days in January",
"28 days in February",
"every other day in April",
"every third day in May"
] | B | the sun setting occurs once per day |
OpenBookQA | OpenBookQA-2033 | 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.
A plant needs to use the roots of itself to move essential things | [
"to the dirt",
"to the sky",
"to the plasma",
"to the buds"
] | D | roots are a vehicle for absorbing water and nutrients from soil into the plant |
OpenBookQA | OpenBookQA-2034 | immunology, lab-techniques, flow-cytometry, cell-sorting
Without lysis, the RBCs overwhelm the cytometer, as they make up around 95% of the cells in human whole blood. White blood cells (leukocytes), on the other hand, only make up 0.1-0.2% of cells, and lymphocytes between about 15 to 50% of leukocytes.
The cell mixture is then analyzed on a cell sorter such as a BD FACSAria.
From: https://commons.wikimedia.org/wiki/File:Fluorescence_Assisted_Cell_Sorting_%28FACS%29_B.jpg
The cells pass in single file past one or more laser beams, which excite the dyes and cause them to fluoresce at a certain wavelength. The user can then use gating to select the combination and intensity of colors they are interested in, and when a cell meets the criteria, it is given an electrical charge, and electro magnets direct it into a collection container.
The following is multiple choice question (with options) to answer.
How can you get your hands on white blood cells? | [
"paint a fence",
"join a gang",
"tour a jail",
"pop a pustule"
] | D | white blood cell destroys pathogens in the body |
OpenBookQA | OpenBookQA-2035 | zoology, entomology, ant, sociality
Giving some reasons for their existence:
To what use is all this effort? Not, it seems, as protection from the elements. The earthworks fall apart in rain, and disintegrate when the earth is dry. Arcades are thin enough to puncture with a tap of a finger, which means a route is weatherproof only when it travels through an underground tunnel, perhaps dug and then abandoned by other animals. Alternatively, near the nest the ants may make a subterranean route of their own: over time, construction crews can scratch away so much soil from the trail surface that the highway sinks from view, at which point the ants seem to be able to construct a thicker, rainproof cover that becomes flush with the surrounding land.
The main function of this relentless building is defense. Because trunk trails extend for dozen of meters, they travel through territory controlled by other ant species. Marauder ants must therefore be organized to protect the trunk trails from aggressive neighbors or even from hapless passerby such as the Diacamma.(...)
...after an arcade has been completed[,] the Diacamma workers could now walk over the trunk trail, blissfully ignorant of the industry below them. if a trail should sink underground, it is as protected as a passage in an army bunker, safe even from human footfalls.
Bulwarks constructed over trails and provisions prevent battles among competing marauder ant colonies as well. Where they are absent, combat can last a day and engage thousands of minor workers, which pour along the line of contact between the armies.
The following is multiple choice question (with options) to answer.
A person stuck alone in the woods could keep themselves a bit more protected by building a | [
"cage",
"clock",
"tepee",
"religion"
] | C | shelter can protect humans from weather |
OpenBookQA | OpenBookQA-2036 | zoology, sensation
Title: Can animals that rely heavily on sonar sense colour? Apparently there're species around as rely heavily on sonar to sense the world around them.
E.g. Bat, Dolphin, Whale ...
The humans, and other terrestrial beings in a lighted world are capable of distinguishing colour in varying degrees of acuity. Is this ability to sense colour in our environment applicable to species (terrestrial, avian, and marine) that rely heavily on sonar? Any animal using sound cannot sense color though sonar directly, though these animals are not entirely blind and can probably see colors in the infrared we can't.
Even on the darkest night there is some light around and all bats use this. Old World fruit bats have colour vision, which is useful to them as they are often quite active in daytime, roosting on trees in exposed positions, rather than tucked away in dark crevices like most microbats, which can see only in black-and-white.
Dolphins have additional senses in addition to seeing they can sense electrical fields. So if an animal has its eyes covered, they will seem to be able to do things you would not expect. Its not the same as seeing the color though.
Such animals using sonar can additionally sense density and hardness as well as other material attributes which would cause the acoustic properties of the material as well as movement.
A hard-bodied insect produces a different quality of echo from one with a soft body, so bats can distinguish between some different groups of insects in this way. They can also determine the size of the object.
What's really interesting is that even human beings can experience this unusual sense. Blind people have learned to echolocate by making clicks with their mouth, and there is a movement to teach this skill.
Anyone can try it. In just an hour or two I was able to tell how close I was to a wall, whether the wall was concrete. I couldn't play video games (2:20 on the link) or see colors though.
The following is multiple choice question (with options) to answer.
Dolphins use echolocation to hunt for | [
"santa claus",
"school children",
"tasty morsels",
"direction in life"
] | C | hunting requires sensing prey |
OpenBookQA | OpenBookQA-2037 | a) Assuming that the ball starts with Joan,
what is the probability that she will have it back after 2 throws?
$\begin{array}{cccc} & \text{John} & \text{Joan} & \text{Kim} \\
\text{John} & 0 & \frac{1}{3} & \frac{2}{3} \\ \\[-4mm]
\text{Joan} & \frac{1}{2} & 0 & \frac{1}{2} \\ \\[-4mm]
Then: . $A^2 \;=\;\begin{pmatrix}\frac{1}{3} & \frac{1}{2} & \frac{1}{6} \\ \\[-4mm]
\frac{1}{8} & {\color{blue}\frac{13}{24}} & \frac{1}{3} \\ \\[-4mm]
\frac{3}{8} & \frac{1}{12} & \frac{13}{24} \end{pmatrix}$
Therefore, there is a $\tfrac{13}{24}$ probability that Joan will have the ball after 2 throws.
Correct!
b) Assuming that the ball starts with Kim,
what is the probability that Joan will have it after 3 throws?
We want $A^3.$
The following is multiple choice question (with options) to answer.
A ball is tossed to a person who misses it and is unable to catch it so | [
"it groans",
"it falls",
"it runs",
"it floats"
] | B | dropping something causes that something to fall |
OpenBookQA | OpenBookQA-2038 | thermodynamics, energy, power
Toyota Corolla, 13 gallon tank, 20% efficiency, 103 kWh usable energy
Tesla Roadster, 56 kWh battery capacity
Chevy Volt, 16 kWh battery capacity
If we compare a liquid Nitrogen car to the Chevy Volt it might not be so bad. But why would we do that? That car can still augment its range with gasoline. A part of the argument for electric cars is that you don't have the same energy loss from idling. Would that be true for a liquid Nitrogen car? There is no reason to believe that.
Let's say we assume a reasonable efficiency of half the isothermal process, which is illustrated in Figure 2 of the reference. Let's also say we'll hold 50 kWh of usable energy in the tank (even though this could still cause range problems). We've increased the tank size by a factor of 4 and the weight of the full tank is now around $1000 kg$. This is close to what many cars weigh.
The energy content relative to gasoline, as well as the alternatives, kills the idea. It would seem to require extremely optimistic assumptions to make it a reasonable proposal before we even get into the discussion about infrastructure needed to make it happen. The most fair comparison would be to other cars that also use alternative fuels, but it fails there too. EVs seem to have better viability on the basis of simple energetics. Maybe you're concerned that we'll run out of Lithium. A vehicle powered by compressed natural gas (not even the super-high pressure tanks that many have hope in) would blow it away, and the tank would be more manageable. Plus the fuel would be (dramatically) cheaper. Plus the infrastructure would be there. Plus, the engine is a proven design. We could do better with coal-to-liquids, we could probably do better with biofuels.
The following is multiple choice question (with options) to answer.
New hydro-electric vehicles will result in gas stations | [
"eventually earning a lot of money",
"being blown up by the governor of California",
"eventually losing a lot of money",
"reporting record third quarter growth"
] | C | as the use of alternative fuels increases , the use of gasoline will decrease |
OpenBookQA | OpenBookQA-2039 | machine-learning
Title: What was going on before PAC learning I am investigating PAC learning (computational learning theory) as a beginner with no previous knowledge of machine learning / AI. I am investigating the model mainly from a historical point of view.
For this, the most important things are of course the results based on the model. There are enough papers out there that document these results. But I also want to write something about what was going on before PAC learning, as to sketch the historical context up to where Valiant came with the notion of the PAC model.
No papers/surveys I've found so far document this, and as someone with no real knowledge of machine learning, it is hard to find this out. I am therefore asking this soft question here, because I believe there are enough experts that can help me with this. References are highly appreciated.
When I can research and study what was going on before PAC, I might get a better appreciation as to why the academic world is so enthusiastic about the PAC model, which is also something interest to document in my historical work!
References are highly appreciated.
An author is expected to address the question of the context and relevance of his results at the begin of his publication. I just skimmed over the introduction of "L. Valiant. A theory of the learnable. Communications of the ACM, 27, 1984." again, and found out that Valiant indeed well covered your question.
The original paper by Valiant is both freely available and not too difficult to read. (Except section 7, which only proves that the author can also tackle challenging mathematical problems, but doesn't contribute much to the real content of the paper.) Reading at least its introduction will be more rewarding than reading my overly long answer to this question, so I suggest to really try it.
The rest of this answer tries to cite some passages from the introduction which should indicate whether reading this introduction might answer the question about the historical context. Note however that an author has the natural prerogative to be biased with respect to such questions.
... such a system would, at least, be a very good start. First, when one examines the most famous examples of systems that embody preprogrammed knowledge, namely, expert systems such as DENDRAL and MYCIN, essentially no logical notation beyond the propositional calculus is used.
The following is multiple choice question (with options) to answer.
Which of these is a learned characteristic? | [
"long hair",
"a big nose",
"doing laundry",
"blue eyes"
] | C | doing chores is a learned characteristic |
OpenBookQA | OpenBookQA-2040 | genetics, genomics, mutations
Title: Understanding conclusions that functional regions are under negative selection? I am reading in notes for a comparative annotation lecture that :
all DNA is subject to mutations
most functional regions are under negative selection (ie., mutations are often deleterious)
The conclusion was:
that pieces of DNA with specific functions (especially genes) tend to be conserved against mutation more strongly than a DNA region with no specific function.
So if i understand it properly, since all DNA can accumulate mutations, the regions of genes that provide some fitness benefits avoid the negative selection of random mutations and are preserved (conserved?).
Also, the author placed in parentheses, (especially genes), therefore are there non coding regions that can provide benefits? Is he referring to "Selfish DNA" like Transposable elements that can have regulatory functions (or so i have heard). Lets assume for simplicity that DNA is globally subjected to the same mutation rate (which is probably not a fully correct assumption).
Now let take a DNA region which is functional (what you meant by giving a fitness benefit), mutations in this region will occur as anywhere else in the genome. Some mutations will be deleterious and reduce the fitness of (or kill) the cell therefore, on the long run, cells that do not carry those deleterious mutations will propagate. This means that now if you look at the genome in the cell that propagated, certain genomic regions will contain less mutations than other because of the negative selection. They were "protected" against deleterious mutation.
Similarly, In multicellular organisms any mutations that reduces the fitness of the germline cells will be negatively selected (again functional regions will be more conserved).
The author was likely referring to regulatory regions. These are regions that do not encode proteins but are very important for gene regulations. Regulatory regions include enhancers, silencers, insulators and locus control regions (Maston GA, 2006). These regions will also be more conserved as deleterious mutations in regulatory elements could reduce the fitness of the cell/germline.
The following is multiple choice question (with options) to answer.
the decrease of something required by an organism has a negative impact on that organism 's what? | [
"soil",
"being",
"survival knife",
"wood"
] | B | the decrease of something required by an organism has a negative impact on that organism 's survival |
OpenBookQA | OpenBookQA-2041 | biochemistry, botany, plant-physiology, photosynthesis
What are typical characteristics of different plants in this regard? I.e., how do common species of plants manage their C consumption before (and after) the development of leaves? There are quite a few questions and thoughts in there, I'll try to cover them all:
First, to correct your initial word equation: During photosynthesis, a plant translates CO2 and water into O2 and carbon compounds using energy from light (photons).
You are correct to assume the C is further used for the growing process; it is used to make sugars which store energy in their bonds. That energy is then released when required to power other reactions, which is how a plant lives and grows. C is also incorporated into all the organic molecules in the plant.
Plants require several things to live: CO2, light, water and minerals. If any of those things is missing for a sustained period, growth will suffer. Most molecules in a plant require some carbon, which comes originally from CO2, and also an assortment of other elements which come from the mineral nutrients in the soil. So the plant is completely reliant on minerals.
Most plants, before a leaf is established or roots develop, grow using energy and nutrients stored in the endosperm and cotyledons of the seed. I whipped up a rough diagram below. Cotyledons are primitive leaves inside the seed. The endosperm is a starchy tissue used only for storage of nutrients and energy. The radicle is the juvenile root. The embryo is the baby plant.
The following is multiple choice question (with options) to answer.
Photosynthesis features | [
"single celled organisms",
"humans",
"cats",
"fish"
] | A | a leaf performs photosynthesis |
OpenBookQA | OpenBookQA-2042 | statistical-mechanics, atmospheric-science, density
A limnic eruption, also referred to as a lake overturn, is a rare type of natural disaster in which dissolved carbon dioxide (CO2) suddenly erupts from deep lake waters, forming a gas cloud that can suffocate wildlife, livestock and humans. Such an eruption may also cause tsunamis in the lake as the rising CO2 displaces water. Scientists believe earthquakes, volcanic activity, or explosions can be a trigger for such phenomenon. Lakes in which such activity occurs may be known as limnically active lakes or exploding lakes.
Picture 1: one of a number of cattle killed by a limnic eruption at Lake Nyos, Cameroon.
We can occasionally prevent the buildup of carbon dioxide by degassing the body of water.
Picture 2: a siphon used by French scientists to de-gas Lake Nyos. The carbon dioxide emerges from its deposits and bubbles into the water, floating to the top.
The following is multiple choice question (with options) to answer.
When a lake receives too much rain it will | [
"swell beyond it's banks",
"reverse direction of flow",
"lower it's water level",
"dry up all together"
] | A | when a body of water receives more water than it can hold , a flood occurs |
OpenBookQA | OpenBookQA-2043 | homework-and-exercises
Title: Is geothermal energy ultimately derived from solar energy? The following question is taken from 10th class science NCERT book chapter 14th.
Most of the sources of energy we use represent stored solar energy. Which of the following is not ultimately derived from the Sun’s energy?
(a) geothermal energy (b) wind energy
(c) nuclear energy (d) bio-mass.
The answer is given as (c) nuclear energy.
I understand that the wind moves because of the uneven heating of the earth by the sun. And biomass uses solar energy for photosynthesis.
How is geothermal energy ultimately derived from the sun? It is not a correct statement:
Geothermal energy comes from the heat within the earth. The word "geothermal" comes from the Greek words geo, meaning earth," and therme, meaning "heat." People around the world use geothermal energy to produce electricity, to heat buildings and greenhouses, and for other purposes.
The earth's core lies almost 4,000 miles beneath the earth's surface. The double-layered core is made up of very hot molten iron surrounding a solid iron center. Estimates of the temperature of the core range from 5,000 to 11,000 degrees Fahrenheit (F). Heat is continuously produced within the earth by the slow decay of radioactive particles that is natural in all rock
italics mine.
Geothermal energy comes from the original energy of the matter solidifying into the sun-planetary system, ultimately from the Big Bang, and from continuous nuclear decays and reactions .
The following is multiple choice question (with options) to answer.
Solar energy called sunlight originates from | [
"jupiter",
"center of universe",
"our celestial star",
"deep space"
] | C | the sun is the source of solar energy called sunlight |
OpenBookQA | OpenBookQA-2044 | reaction-mechanism, experimental-chemistry
So, to answer the question: "which reagents in the experiment are responsible for changing the time before the colour change in the clock", the answer is H2O2 and Vitamin C. Now, while the rate-controlling step, associated with the slowest reaction is H2O2 (creating the colourful I2 highlighted by starch), some Ascorbic acid must be present to turn the solution clear again.
On the question:"Can you please clarify which reagents cause the increase/decrease in time of the chemical clock reaction?", the strength of the H2O2 (try changing from 3% to 10%) and the pH of the hydrogen peroxide (try adding alkaline Washing Soda Na2CO3 to the H2O2), both I would likely expect to have impacts on the Vitamin Clock timing.
The following is multiple choice question (with options) to answer.
Which ingredient may cause chemical change? | [
"almonds",
"milk",
"citrus juice",
"olive oil"
] | C | acid can cause chemical change |
OpenBookQA | OpenBookQA-2045 | mass, terminology, matter
Title: What is the meaning of "matter" in physics? What is the meaning of matter in physics? By defining matter in terms of mass and mass in terms of matter in physics, are we not forming circular definitions? Please give a meaning of "matter" in Physics that circumvents this circularity.
What is the meaning of "matter" in physics?
It doesn't matter. Sometimes matter means "particles with rest mass". Sometimes matter means "anything that contributes to the stress-energy tensor". Sometimes matter means "anything made of fermions". And so on. There's no need to have one official definition of the word "matter", nothing about the physical theories depends on what we call the words.
Discussing this any further is just like worrying about whether a tomato is really a fruit or a vegetable. A cook doesn't care.
The following is multiple choice question (with options) to answer.
matter is made of what? | [
"united atoms",
"sound",
"feelings",
"bonds of friendship"
] | A | matter is made of molecules |
OpenBookQA | OpenBookQA-2046 | electrostatics, electricity, water, everyday-life, air
Title: The Ultimate Hand Dryer I have come across many hand dryers that attempt to dry your hands really fast after you wash them. Here are two of them:
XLERATOR
http://www.exceldryer.com/
Dyson Airblade
http://www.dysonairblade.com/homepage.asp
So I guess I have a ridiculously high standard cause I think even these are too slow.
Would it be possible to create a large static electric field to attract the water molecules off of your hand? Can someone offer some ideas that would remove the water off of your hand using some type of electric field generated by charged plates or something? Water molecules don’t carry an electric charge (and if they do, you don’t want them on your hands…). The dipole moment of water molecules can only be used to rotate them in space, not to move them. Additionally, the forces that apply to water molecules on your hands also apply to water molecules in your hands. So even if you somehow managed to apply a sensible force on these water molecules, this would get rather uncomfortable. The same problem arises if you attempt to heat them up by means of electric resonance (similar to a microwave).
I therefore doubt that it would be possible to build a device based on electric fields rather than moving air, that removes water molecules from the surface of your skin.
However, it might be possible to vaporise the water on your hands using strong infrared lamps. This might lead to other problems, though, such as the focusing of infrared radiation on small areas of the skin by water drops.
The following is multiple choice question (with options) to answer.
What does a hand dryer produce? | [
"growth",
"money",
"carbs",
"hotness"
] | D | a hand dryer produces heat |
OpenBookQA | OpenBookQA-2047 | everyday-chemistry, water, absorption
Fig. B is complete speculation on my part as I did not return to the home during Winter to observe it. However in Spring when I returned, all of the tubs had experienced a change in their appearance.
All the tubs were now dry again, presumably down to evaporation due to increasing weather temperatures. And therefore releasing all that moisture back into the building again!
Three of the tubs were largely unchanged with some noticable "caking" together of the salt into crumbly, grainy lumps which returned to normal looking salt grains when crushed.
The most profound change from the remaining tubs was as you see in Fig. C of the diagram.
The salt had actually accumulated on the walls of the tub as a fine sediment. This suggests that water had accumulated in large amounts in the tub and had in fact risen higher than the original depth of the dry salt grains! I'd estimate that the tub would have had to accumulate about 0.5kg of water in order for the water/salt solution to reach the depth indicated by the dry sediment.
The salt had solidified into a single, large mass. The volume seemed to have increased noticeably but the density had also decreased accordingly, so the salt had basically expanded in it's container and solidified. It was crumbly and brittle and some of it had been reduced to a very fine sediment.
The home is a single storey, about 12m x 4.5m x 2.5m in volume.
My questions then:
Is this a valid technique for capturing excess moisture over Winter?
Are my observations and presumptions reasonable... Is Fig. B what really happened?
What is the chemistry / physics process that caused the salt to be transformed from Fig. A to Fig. C?
How many times did the tubs cycle between states B and C? Was it a single cycle that lasted all of winter, or a daily cycle following ambient weather temperatures? I could not tell just by looking at C on the last day of the experiment. According to Transportation Information Service: Salt:
The following is multiple choice question (with options) to answer.
Depressions in building materials that fill with frozen water will | [
"decompose",
"collapse",
"contract",
"expand"
] | D | when water freezes , that water expands |
OpenBookQA | OpenBookQA-2048 | homework-and-exercises, forces, kinematics
Title: Homework Question Transformation Energy A $1400kg$ car is approaching the hill shown in the figure at $14.0m/s$ when it suddenly runs out of gas.
What is the car's speed after coasting down the other side?
I think I have to use this equation
$mg(\Delta h)=\frac 12 m(\Delta v)^2 $
$(1400)(9.81)(\Delta h)= \frac12 (\Delta v)^2$
I am not sure if this is correct. If it is, what do I plug in for $\Delta h$? You have to use $\Delta h$=$5m$ since it is the height by which the car descends along the course of the journey. And instead of $$mg\Delta h=\frac12 m(\Delta v)^2$$ you should rather use $$mg\Delta h=\Delta KE=\Delta (\frac12 mv^2)=\frac12 m (v_f^2-v_i^2)$$
where $v_i=14ms^{-1}$ and evaluate for $v_f$.
The following is multiple choice question (with options) to answer.
Liz's 72 Mustang stopped on the highway because it had run out of fuel. What does she need? | [
"an available electrical outlet",
"A product derived from oil",
"a clean solar panel",
"a new set of spark plugs"
] | B | oil is a source of gasoline |
OpenBookQA | OpenBookQA-2049 | physical-chemistry, analytical-chemistry, crystal-structure, materials
Why can't "automated machining" match the precision of (assuming the
alternative) "machining by hand"?
In the polishing phase is not only a matter of precision but rather on adapting to the changes of surface. Expert polishers are incredibly well paid, they know how to modulate the polishing pattern and force to solve the specific problem of the surface (e.g. scratches valleys etc. etc.) nowadays automated polishing still can not adapt quickly to the chaotic behaviour of the surface.
I quote the article Towards an automated polishing system: capturing manual polishing operations:
Some automated solutions have already been proposed to assist or
replace human operator. However, these solutions typically lack
flexibility and dexterity that are provided by human operators. For
example, some of the polishing skills that are particularly
challenging to automate include rapid reasoning and decision making
based on visual inspections, and fast adjustment of the polishing
patterns, e.g. when a surface defect is identified
So I would rather think that with "atomic feeling" they are just referring to the impressive, not well-defined skills set that an expert polisher has matured in his career to reach "atomic" polishing results!
Or maybe not?
Looking at the answer of @Buttonwood it seems that the roundness error was +- 28 nm and the diameter around 10 cm that would be a signal with an amplitude of 56 nm and very long wavelength of around let's say 2 cm, that would fit into the range in the Nature article that I linked (even if so long wavelength would indeed necessitate another study...)so maybe somehow he was able to detect this imperfection on the roundness as well for guiding the polishing? In the meanwhile, at PTB it seems they found a way to replace the atomic feeling of Achim, as shown in this video.
The following is multiple choice question (with options) to answer.
A highly polished surface will | [
"absorb light energy",
"redirect light energy",
"attract shadows",
"shatter"
] | B | shiny things reflect light |
OpenBookQA | OpenBookQA-2050 | entomology
Title: What is the name of this tiny creature? It looks like a tiny piece of moving cotton? By chance, I saw this tiny insect on my bag a few days ago in Sydney. Am I the first person who has pinpointed this animal?! If not can you please let me know its name? From your image, it looks like it might be a woolly aphid. I just did a bit of cursory research, and it looks like they're often described as floating pieces of fluff, that seem to wander instead of directly heading somewhere. The fluff on their back is actually wax produced as a defense mechanism from predators and the like. I hope this is what you were looking for!
The following is multiple choice question (with options) to answer.
A skunk produces a bad what? | [
"food",
"reek",
"computer",
"title"
] | B | a skunk produces a bad odor |
OpenBookQA | OpenBookQA-2051 | visible-light, scattering, atmospheric-science, sun
It's tricky to figure out what it's a shadow of, but straight lines in the sky like this are almost always shadows of land features.
See this similar photo where the shadows are attributed to a thunderhead, in line with your suggestion about the shadow coming from a cloud.
The following is multiple choice question (with options) to answer.
Which would directly follow the appearance of grey clouds? | [
"UFOs",
"planes",
"sleet",
"tsunami"
] | C | grey clouds are a source of precipitation |
OpenBookQA | OpenBookQA-2052 | zoology, behaviour, mammals, rodents
Title: Why do Guinea Pigs chirp / sing? Ok, so this appears to be quite a mystery. Me and my girlfriend have 2 Guinea Pigs, 1 male and 1 female.
My girlfriend once picked up the female one and took her outside into our garden. The Guinea got scared for some unknown reason and jumped out of my girlfriend's arms and fell down hard.. That night, the female Guinea woke us up with some very strange sounds. She sounded like a chirping bird.
Since then, she sometimes repeats these sounds (most often at night, but not always). Mostly, we are puzzled as to why as there is often no apparent reason for her sounds. Also, when she makes the sounds, she appears to be in a trance-like state, making no movements at all.
Looking for the answer online I found many discussions on the subject like this one or this one. Mostly, the sounds (and the often mentioned trance like behavior) appear to be interpreted as either (1) alarm sounds, (2) loneliness sounds or (3) happiness sounds.
There are also recordings of it one Youtube, like this one.
What I was wondering:
Does anybody know about some actual research that has been committed on this subject? If so, what were the results?
I'm just so very curious to find out! I found this question very interesting so I did some research. Here's a brief summary of what I've found:
Researchers have found that there are 11 different call types. Some of these include a "sharp alarm cry", "sociable clucking", chutter, whining, purring etc. Using body position and behaviour, researchers attempted to associate these vocalizations with behaviour. Some vocalizations had no apparent associated action including what researchers designated the "chirrup" ( I think this is similar to what your guinea pig might have emitted.)
For more information you can read the results section of this paper by Berryman. You can find a full description of each of the 11 calls and their assumed cause or purpose. Some involve social interaction, reproduction, and distress. Much of the research regarding Guinea pig vocalization involves communication and response between mothers and pups.
In short, it seems as though this chirping behaviour your Guinea pig is exhibiting is normal, but not of any known cause.
The following is multiple choice question (with options) to answer.
A piglet was accidentally stepped on. In order to heal up, the piglet is offered | [
"a new toy",
"a pet puppy",
"slop",
"a warm bath"
] | C | an animal requires nutrients to grow and heal |
OpenBookQA | OpenBookQA-2053 | entomology
Title: Constantly wiggling moth pupa - will it emerge soon? Today I found a moth pupa in the soil in my garden in western Sweden. It's about 15 mm long.
I have found similar ones before, but this one is wiggling a lot more, even after I put it down and put a bit of dirt over it. It's been moving for more than an hour now, but less now than in the beginning.
I was hoping to see it emerge, but if it will take more than a day or so, I will probably put it back. So, what I'm wondering is if this wiggling is any indication of how soon it will emerge. Or if there are other ways to tell.
Update: an hour later it has stopped moving. Maybe it was just very disturbed by my presence. I'm keeping it in a jar with soil and a stick for climbing up on, and I'll decide what to do with it tomorrow.
Update: 12 hours later and it seems very still. But I'm letting the question remain since I really want to know if there are any signs to look for.
Final update: After 16 days it had turned almost black, and was still very active when handled.
And after 17 days this moth came out: I posted the same question on tumblr and got an answer:
It depends on the species. This one looks like a Noctuid. I’d give it
two weeks to a month or so. You may be able to see its wings showing
through the darkening pupal case when the time draws near! Just make
sure you give it somewhere to climb up and expand its wings when it
ecloses.
After keeping it until the moth emerged, I now know that wiggliness is not an indication of maturity, but turning dark is.
The following is multiple choice question (with options) to answer.
A moth that experiences a metamorphosis will change | [
"sex",
"shape",
"species",
"religion"
] | B | a moth undergoes metamorphosis |
OpenBookQA | OpenBookQA-2054 | species-identification, zoology, ornithology
Title: Identification by tail feather I saw the remains of a bird today I did not recognize, and it was pretty mangled so it was hard to describe it. It was about the size of a robin. However, it had a dark brown mottled body like nothing I have ever seen. I have included below a tail feather from the bird which is 5 inches long. I am sure it is not a thrush or a woodcock or a kestrel. So what was it?
Location is Great Bay, Portsmouth, New Hampshire, United States. I believe this is a tail feather (or retrix) from an adult male eastern whip-poor-will (Antrostomus vociferus). See right image below (click to zoom):
.
Source: USFWS Forensics Laboratory
Details:
The brown, mottled appearance and the size (~12 cm) match that of the OP's specimen.
A great resource for exploring bird feathers: https://www.fws.gov/lab/featheratlas/
The whip-poor-will's breeding grounds include the OP's location (i.e., New Hampshire), and according to All About Birds this species could still be present even late in the year ("they seem to leave between early September and late November.").
Orange is breeding. Source: All About Birds.
The whip-poor-will is a medium sized bird and similar in size to an American robin.
Whip-poor-will: 22-26 cm ; Robin: 20-28 cm
Eastern whip-poor-will, (c) Paul Cools, source: inaturalist
The following is multiple choice question (with options) to answer.
A particular bird has very bright multi-colored feathers. This could help them | [
"find the mother of its future children",
"attract a plane to rescue them",
"find a good source of food",
"become famous in movies"
] | A | coloration is used to find a mate by some animals |
OpenBookQA | OpenBookQA-2055 | ecology, population-dynamics, ecosystem, antipredator-adaptation, predation
I would also like to talk about other things that might be of interest in your model (two of them need you to allow evolutionary processes in your model):
1) lineage selection: predators that eat too much end up disappearing because they caused their preys to get extinct. This hypothesis has nothing to do with some kind of auto-regulation for the good of species. Of course you'd need several species of predators and preys in your model. This kind of hypothesis are usually considered as very unlikely to have any explanatory power.
2) Life-dinner principle. While the wolf runs for its dinner, the rabbit runs for its life. Therefore, there is higher selection pressure on the rabbits which yield the rabbits to run in average slightly faster than wolves. This evolutionary process protects the rabbits from extinction.
3) You may consider..
more than one species of preys or predators
environmental heterogeneity
partial overlapping of distribution ranges between predators and preys
When one species is absent, the model behave just like an exponential model. You might want to make a model of logistic growth for each species by including $K_x$ and $K_y$ the carrying capacity for each species.
Adding a predator (or parasite) to the predator species of interest
... and you might get very different results.
The following is multiple choice question (with options) to answer.
A rabbit might die if | [
"it has insufficient money to buy food",
"all the greenery was burned in a fire",
"all of the rabbit's prey has disappeared",
"all the other rabbits shun it"
] | B | an animal requires enough nutrients to survive |
OpenBookQA | OpenBookQA-2056 | mass, astrophysics, neutron-stars, white-dwarfs
Title: Why is the least massive neutron star less massive than the most massive white dwarf? Martinez et al. (2015) gives an example of a neutron star with mass as low as $1.17M_\odot$ (solar masses).
There is also the recent discovery of this candidate neutron star which is apparently only $0.77M_\odot$.
Yet the Classical Chandrasekhar limit for a white dwarf is $1.44M_\odot$, while the "true Chandrasekhar limit" "true Chandrasekhar limit" is around 1.37 to 1.38
What is the reason for this discrepancy? Well because they have different formation pathways. White dwarfs don't (often) become neutron stars, so there is no obvious reason why neutron stars should exceed the Chandrasekhar mass for carbon/oxygen white dwarfs.
However, there is reasonable cause to suppose that neutron stars should be heavier than the Chandrasekhar mass for an "iron white dwarf". That is because the main pathway to create a neutron star is a core collapse supernova. This is triggered by an instability (caused by photodisintegration or electron capture) that occur as the electron-degenerate iron core accretes mass and approaches its Chandrasekhar limit.
The Chandrasekhar mass is composition dependent. The "classic" limit derived by Chandrasekhar is given by
$$M_c = 1.44\left(\frac{\mu_e}{2}\right)^{-5/3}\ ,$$
where $\mu_e$ is the number of mass units per electron. For carbon and oxygen, $\mu_e= 2$, for iron $\mu_e = 56/26$ and $M_c = 1.27 M_\odot$.
The following is multiple choice question (with options) to answer.
Which is the least massive? | [
"the Earth",
"the moon",
"the sun",
"the solar system"
] | B | the earth has more mass than the moon |
OpenBookQA | OpenBookQA-2057 | 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.
Which of these is a side effect of vegetable farming? | [
"clowns",
"happy dogs",
"fertilizer sickness",
"cats"
] | C | runoff contains fertilizer from cropland |
OpenBookQA | OpenBookQA-2058 | temperature, light, heat
Title: Why does sunburn cause fever? Today I found out that sunburns can cause fever.
What I don't understand is how/why? In my understanding fever is the side effect of an immune reaction against an intruder, mainly bacteria (though I admit I can be wrong).
Google searches like "can sunburn cause fever" only bring up that it is possible, but not why. Here is a good article on the topic.
https://www.nlm.nih.gov/medlineplus/ency/article/003227.htm
But it's most likely due to the fact that a sun burn is an actual burn on the skin that can cause inflammation, inflammation can in turn cause fever. Also having a really bad sunburn can open you up more to the possibilities of skin infections. If this happens then once again you might get a fever due to infection. If you really want to find out more on the cause of fever after sunburn you need to examine the pathophysiology of fever and why fever happens. I bet my money on fever due to skin inflammation after a sunburn, I guess the real question would be why does inflammation cause fever since sunburn = skin inflammation
Here is a good article
http://antranik.org/inflammation-and-the-pathophysiology-of-fever/
The following is multiple choice question (with options) to answer.
Heat causes | [
"water to turn to vapor in a process called condensation",
"water to melt in a process called condensation",
"water to turn to vapor in a process called evaporation",
"water to melt in a process called abomination"
] | C | evaporation is when water is drawn back up into the air in the water cycle |
OpenBookQA | OpenBookQA-2059 | species-identification, zoology, bone-biology, bone
Title: What is this bone from? This object showed up on my fire escape in New York city. It appears to be some kind of bone. It's a bit smaller than an adult human hand. What animal is it from? Given the size and thin/elongated ilia as well as the urban location, I think a domestic cat and/or a raccoon are likely candidates. I'm leaning toward cat.
Cat pelvis:
VCA Hospitals
Ventral view of domestic cat pelvis; Source: BoneID
Raccoon Pelvis
Anterior view of raccoon pelvis; Source: BoneID
I'm not an expert in differentiating these two species' bones. I will note that your specimen is more or less in between the sizes of these two species. Your size is probably closer to the raccoon, but a cat is just more likely given the location.
The most noticeable trait that stands out to me is the size/pointedness of the ischial tuberosity, which better matches that of the cat.
The following is multiple choice question (with options) to answer.
Which is likely to be seen at the zoo? | [
"a polar bear in the jungle habitat",
"a zebra in the arctic zone",
"an alligator in the petting zoo",
"a snake under a hot lamp"
] | D | some animals live in zoo exhibits |
OpenBookQA | OpenBookQA-2060 | \tag{2}$$ Combining $(1)$ & $(2)$, we obtain $(\star)$.
The following is multiple choice question (with options) to answer.
A successful combination of things is | [
"tomatoes and peppers",
"nylon and carpet",
"milk and honey",
"sand and socks"
] | C | An example of combining two substances is pouring one substance into the other substance |
OpenBookQA | OpenBookQA-2061 | How about this? There is a 30% chance you'll go to New York and a 100% chance you'll go to the Empire State Building if you go to New York (because why else would you go to New York? kidding...). Does this mean there's a 100% chance you'll go to the Empire State Building? Well, since you have to go to NY to go to the ESB, that would mean there's a 100% you'll go to New York - and now we're being contradictory! So this interpretation makes no sense and is never what we mean mathematically or in plain English.
"The DVD Is either at my parents, my porch, or my living room. What is the % chance it's on my porch?", the answer is 33%.
This is definitely wrong. I'm pretty sure you either have ebola or you don't have ebola. Up to you whether you need to call 911 and get yourself quarantined right away because there's a 50% chance you have ebola. Or perhaps the doctors gave your sick relative 6 months to live, but your relative might live a year or two years or three years or four years or five years, which means there's at least an 86% chance the doctor is wrong.
Now put 10 red m&ms in a bag and 1 blue one. Grab one without looking. Since there's two possibilities, there's a 50% chance it's a blue one, right? So I'll bet you a dollar that it's red and you bet me a dollar that it's blue, and we'll see who's paying for lunch later.
The following is multiple choice question (with options) to answer.
In NYC, what would you expect during December? | [
"less day light",
"less rain",
"less weather",
"less moonlight"
] | A | when the season changes , the amount of daylight will change |
OpenBookQA | OpenBookQA-2062 | fluid-dynamics, differential-equations
Title: Flow around a rock in a river: which differential equation? I'm a canoist, so I know that when I go with my kayak behind a rock in a river, I feel a current that is opposite to the river current.
I'm also I student mathematician, so I would like to see this phenomenon from equations. But I don't know anything about the equations that govern fluid dynamic.
So my problem is: let be $W = \mathbb{R} \times [-2, 2]$ the river and $R = B_1(0)$ the rock (a ball inside the river). Let be $M = W \backslash R$ the river without the rock, i.e. where the water could flow. Let be $\phi: \mathbb{R} \times M \to M$ a function such that $\phi(t, x)$ is the position at time $t$ of the fluid particle that at time $t = 0$ was in position $x$. Let be the water flow from left to right. My question is: what differential equation for $\phi$ I have to solve? And does this equation predict the correct flow behind the rock? The simplest model that fits is potential flow around a cylinder (or a circle in 2D). This assumes an an inviscid, incompressible fluid with no vorticity, which is too simple to model the backflow. The backflow occurs because of viscosity produces boundary layer separation.
I think the second simplest model possible would be to solve the steady-state Navier Stokes equations for an incompressible fluid. Then it is just $$(\mathbf{v}\cdot \nabla)\mathbf{v}-\nu\nabla^2\mathbf{v}=-\nabla w$$ $$\nabla\cdot \mathrm{v}=0$$ where $\nu$ is the viscosity and $\nabla w=(\nabla p)/\rho$ is the pressure term (or other forces expressed as hydraulic head). Since you are interested in the 2D case it can also be turned into an equation for stream functions that leaves out the pressure term.
The following is multiple choice question (with options) to answer.
Where would a river flow downwards? | [
"at the zoo",
"on the mountainside",
"on the prairie",
"on flat land"
] | B | the slope of the land causes a river to flow in a particular direction |
OpenBookQA | OpenBookQA-2063 | javascript, object-oriented, design-patterns, simulation
draw() {
const imageData = this.ctx.getImageData(0, 0, this.ctx.canvas.width, this.ctx.canvas.height);
const data = imageData.data;
for (let x = 0; x < this.width; x++) {
for (let y = 0; y < this.height; y++) {
let i = 4 * (y * this.width + x);
if (this.array[y][x] == null) {
// white water
data[i] = 255;
data[i + 1] = 255;
data[i + 2] = 255;
data[i + 3] = 255;
} else if (this.array[y][x].species === 'fish') {
// yellow fish
data[i] = 255;
data[i + 1] = 255;
data[i + 2] = 0;
data[i + 3] = 255;
} else if (this.array[y][x].species === 'shark') {
// red sharks
data[i] = 255;
data[i + 1] = 0;
data[i + 2] = 0;
data[i + 3] = 255;
}
}
}
this.ctx.putImageData(imageData, 0, 0);
document.getElementById('chrononText').innerHTML = this.chronon;
document.getElementById('fishText').innerHTML = this.numFish;
document.getElementById('sharksText').innerHTML = this.numSharks;
}
tick() {
this.chronon++;
for (let x = 0; x < this.width; x++) {
for (let y = 0; y < this.height; y++) {
if (this.array[y][x] == null) {
// do nothing
} else {
this.array[y][x].tick(this.chronon);
}
}
}
}
}
The following is multiple choice question (with options) to answer.
A deer, shark, human and rose share which common activity? | [
"eating cheese",
"marrying",
"defecating",
"building ships"
] | C | all living things eliminate waste |
OpenBookQA | OpenBookQA-2064 | carbon-cycle, biogeochemistry, carbon, limestone
The rate of this process is dependent on how much energy you are prepared to throw at it. A fleet of several thousand nuclear reactors running 24/7 on this problem would do it.
Burial
Well, brute force sounds a bit expensive.. so we can try the approach mentioned by Jack R Woods. In this case, we capture CO2 (this still takes energy, although not much in theory), and pump it into thick basalt formations such as the ones in Iceland. Many flood-basalt igneous provinces have the combination of low-silica rocks and high porosity that are ideal for this kind of sequestration. The rate is limited by how fast you can capture CO2 out of the air. You could imagine using a Solar Updraft Tower - this would give an air flow that you could extract CO2 from, and provide power for the process. If the reaction goes as planned, it's safe on geological timescales.
The problem is, as ever, getting enough resources to build these things on the scale required.
The following is multiple choice question (with options) to answer.
Which process does the slate that comes from shale come from? | [
"height",
"compression",
"gravity",
"steel"
] | B | shale can be metamorphosed into slate by increased pressure |
OpenBookQA | OpenBookQA-2065 | meteorology, geomorphology, climatology, atmospheric-circulation
Source Commons Wikipedia.
The cold waters near the ocean surface results in a cool, stable coastal atmosphere. In this region, evaporation from the ocean is reduced and produces extremely low rainfall over land. Precipitation is limited to morning fog and produces some of the driest ecosystems on Earth. The Atacama desert is the best example of such environment with average rainfalls of 15 mm/year (the driest non-polar region). In some areas, they are trying to take advantage of the little moisture the fog (Camanchaca) brings to establish some agricultural zones. The fog droplets are too small (1-40 micrometers) to form water drops and precipitate, so they use fog-catchers to collect moisture from the fog.
Source: newatlas.com
The following is multiple choice question (with options) to answer.
Where would the environment be driest? | [
"the arctic tundra",
"the Gobi Desert",
"the Salton Sea",
"the rain forest"
] | B | a desert environment is dry |
OpenBookQA | OpenBookQA-2066 | forces, centrifugal-force
Title: MotoGP motorcycles lift front wheel while exiting curve I've seen multiple times now in MotoGP that motorcycles were leaving a curve, and because of the acceleration the front wheel is slightly leaving the ground. But at the same time they were still leaning to the inside of the curve, just following the curve to the end and then going straight again.
Now I understand why the can lift the front wheel. But what I don't get is why they can still finish the curve on one wheel, instead of just going straight and leaving the track. I thought the front wheel is supposed to use its traction on the surface of the ground to lead the motorcycle around the curve, but they keep going around the curve while the front wheel is in the air.
Which force makes the motorcycle do a curve while the front wheel is not touching the ground?
I'm not sure if my explanation was understandable, here are some pictures of what I mean. They still lean into the curve and follow the curve while already lifting the front wheel:
http://50to70.com/wp-content/uploads/2012/07/jorge-lorenzo-motogp-2012-mugello-test.jpg
http://farm3.static.flickr.com/2224/2331275819_ccbe52129f.jpg It is an interesting question and I know exactly what you mean. I often look at the likes of Stoner performing what you describe and think "wow!". Right, for the answer...
The following is multiple choice question (with options) to answer.
A hard wind blowing at the back of a bike that is being peddled forward will | [
"make it stop",
"speed it up",
"slow it down",
"blow it up"
] | B | force causes the speed of an object to increase |
OpenBookQA | OpenBookQA-2067 | thermodynamics, food
Title: Boiling Pasta resulting in a Torus like shape? I noticed when I was boiling pasta the other day that the pasta uniformly spread out and formed a donut like torus. Why does this happen? Does it have to do with the shape of the pot? I tried to take a picture when it was boiling, but steam got all over my lens. So, this is a more 2d version of what the pasta looked like with boiling (while boiling, the pasta strands were uniform and seemed to be repelled out uniformly from the center of the pot. The walls of your pot act like a thermal sink that transfers heat to the surrounding environment. Therefore, the water temperature gets hotter as you move towards the center of the pot. The cold water then sinks and the hot water pushes up through the center, creating the donut-like torus you are describing.
The following is multiple choice question (with options) to answer.
A pot of water is ready to cook noodles when it is boiling, as noted by | [
"salty taste",
"water smell",
"bubble production",
"cool water"
] | C | boiling is when liquids are heated above their boiling point |
OpenBookQA | OpenBookQA-2068 | special-relativity, waves, speed-of-light, acoustics, relative-motion
Title: Can sound be faster than 300m/s? If you sit in a car and it's driving $300{m \over s}$ and you clap your hands for a very very short sound, will it's wave be $600{m \over s}$ fast, because it adds the speed of the car?
Or will it be $300{m \over s}$ because it is just the point of origin that matters and from that point it travels away?
If the answer of the title question would be yes, that would also mean that light can also travel faster than speed of light, right? (I assume sound and lightwaves can be compared as both contains electeomagnetic waves) The speed of sound of 340 m/s is measured with respect to air. So here we can mention two cases:
If you are inside a car that is moving at 340 m/s in the highway and the windows are closed (so that the air inside the car is also moving at that speed), the sound of your clap will move at 680 mm/s with respect to the ground. This is because it moves at 340 m/s with respect to the air inside the car.
Imagine the same situation but with a car that has no roof nor windows. Then you, inside the car, will find that the air moves at 340 m/s backwards. If you clap in this situation the sound waves will move at 340 m/s in the air, but because this air moves at 340 m/s backwards you will see that the sound waves do not move at all.
The second case is exactly what happens in this picture:
When the supersonic aircraft is moving exactly at (or very near) the speed of sound (both with respect to the air), the waves travel at the same speed and they accumulate to form that peculiar cone.
In the case of light the case is different because light speed is 300000 km/s with respect to space itself. And you cannot move with respect to space, you move in space with respect to other things. Motion is relative. So the speed of light is the same for everyone independent of the speed of the observer (or the source).
The following is multiple choice question (with options) to answer.
Which would reach the other side of a room the fastest? | [
"the world's fastest bird",
"the world's fastest sprinter",
"the light from a flashlight",
"an extremely loud audio signal"
] | C | a flashlight emits light |
OpenBookQA | OpenBookQA-2069 | co2, oxygen
Title: Could earth run out of O2? Death in a closed environment due to lack of O2 is actually not that bad:
https://www.youtube.com/watch?v=kUfF2MTnqAw
And as far as I know as we are cutting down our life saving woods and jungles less $O_2$ is being produced and more $CO_2$ is not converted back to $O_2$.
Greenpeace and others tell us how bad this fact is.
But: If it continues like this, is it possible for humanity to extinct itself because we run out of $O_2$ and breath in too much $CO_2$?
Wouldn't it be much nicer than like burning to death if the $O_2$ would disappear? No, that will not happen. There is just too much oxygen in the atmosphere.
Over 20% of our atmosphere is oxygen.
Only about 0.04 % of our atmosphere is CO2, so too much CO2 would kill us much sooner than the lack of oxygen.
If you reduced the oxygen concentration in the atmosphere from 20.8% to 19.8%, you wouldn't even feel the difference. If you reduced it to 15 %, you would still survive it. You could even survive 10 % for short time periods.
However, let's see what would happen if you added CO2 as a replacement for the oxygen you removed: at 1%, you would feel extreme dizziness. At 5% you would lose consciousness and die.
But the real danger in CO2 lies elsewhere. Even an increase from our current 0.040 % to 0.045 % could cause a lot of damage to the climate, and an increase above 0.055 % could be disastrous. Unless you are locked in a small room, the reason why the increase of CO2 and decrease of oxygen will be dangerous won't be because you wouldn't be able to breathe. Changes significantly smaller than those required to make breathing difficult, would be enough to wreck the ecosystem, cause drought, desertification, starvation, and economic collapse.
Also note, that trees are very important for the water cycle, as a habitat for many species, and for preventing soil erosion, but they play an insignificant role in producing oxygen. Most of our oxygen is produced by algae.
The following is multiple choice question (with options) to answer.
Long decayed plant life would most likely fuel our | [
"nuclear power plants",
"dogs",
"motorcycles",
"bodies"
] | C | forming fossil fuels requires decaying vegetation |
OpenBookQA | OpenBookQA-2070 | entomology, invertebrates
Title: Selection for less efficient egg transfer in Human Botfly life cycle I have heard that the Human Botfly transfers its eggs through other invertebrates, and it strikes my curiosity that if an insect could simply land on its host directly to deposit its eggs, then why have intermediate hosts?
I have speculated that the vectors may be better specialized for penetrating hosts, and that penetrating hosts may be difficult, or that approaching hosts is risky. Another speculation on my part is that the Human Botfly may be filling a niche where it does not need to compete. In multi-host complex life cycles (CLCs), an intermediate host often aids in the dispersal of offspring.
In general terms, an animal, say a botfly, have an ultimate "purpose" or 'goal' to spread their genetic information as much as possible. This could mean producing a large number of offspring and hoping some survive or it could mean having one offspring, investing a lot of energy and ensuring it does survive. Regardless, spreading genetic information often requires offspring to disperse (or be spread) a great distance, which may allow the individuals' genetic information to dominate an new region.
In the case of botflies, having an intermediate host means the genetic information can be spread a great distance.
If you're looking for a more thorough explanation of complex life cycles, this paper describes it well. There is also this site more specific to the botfly which is not peer reviewed, but well-researched and descriptive.
The following is multiple choice question (with options) to answer.
A lily wants to spread its genetic material around and so relies upon | [
"beads",
"assistance",
"shopping",
"patients"
] | B | seed production requires pollination |
OpenBookQA | OpenBookQA-2071 | thermodynamics, temperature, thermal-radiation, equilibrium
Note that although the emissivity does not affect the equilibrium temperature it does affect the speed that the object attains equilibrium. The higher the emissivity the faster the object will reach equilibrium. So while your two objects are warming up they will warm up at different rates and therefore will temporarily have different temperatures.
The following is multiple choice question (with options) to answer.
When a dog adjusts its temperature | [
"it pants",
"it finds water",
"it sweats",
"it shirts"
] | A | panting is when an animal hangs its tongue out of its mouth to adjust to hot temperatures |
OpenBookQA | OpenBookQA-2072 | python, game, adventure-game, python-2.x
def CraftingList():
print ">>> Crafting List <<<"
print "1. Tinder: 1 x Wood > 3 x Tinder"
print "2. String: 1 x Plant Fibre > 1 x String"
print "3. String: 1 x Dead Grass > 1 x String"
print "4. String: 1 x Cloth > 2 x String"
print "5. Cloth: 1 x Clothes > 3 x Cloth ***Tearing Clothes will increase the rate of heat loss!"
print "6. Bow Drill: 1 x String, 2 x Wood > 1 x Bow Drill"
print "7. Bone Knive: 1 x Bone, 1 x String > 1 x Bone Knive"
print "8. Bandage: 1 x Cloth > 3 x Bandage"
print "9. Fire Torch: 1 x Wood, 1 x String, 1 x Vaseline, 1 x Tree Bark > 1 x Fire Torch"
print "10. Fishing Rod: 1 x Wood, 1 x String, 1 x Knive > 1 x Fishing Rod"
print "11. Water Bottle: 1 x Rabbit Skin > 1 x Water Bottle"
print "Which one do you want to craft?"
print
return raw_input(">>> ")
The following is multiple choice question (with options) to answer.
A person wants to use a raw material to make a toy, so they use | [
"bronze",
"plastic",
"denim",
"logs"
] | D | if something is a raw material then that something comes directly from a source |
OpenBookQA | OpenBookQA-2073 | acid-base, redox
As you can see, there is no sudden catastrophe as the second proton becomes more acidic than the first. As the second ionisation becomes more favourable, it smoothly and continuously suppresses the formation of $\ce{HA-}$ . Something nice does happen at the crossover point, where $\mathrm{pK_{a_1} = pK_{a_2}}$, namely all species are present in the same concentration when $\mathrm{pH = pK}$. However, this not surprising if you look at the equations above.
For good measure, here are all the plots once again, now with a logarithmic y-axis. It's nice to see that even with the suppression of $\ce{HA-}$, it still exists as a trace in the background, and still behaves smoothly.
And to finish things off, now here are graphs showing the mole fraction of each unique species as $\mathrm{pK_{a_2}}$ varies from 10 to -6, in decrements of 1 unit of $\mathrm{pK}$. I rather like the subtle way the curves for the fully protonated and fully ionised species change, as the intermediate ion stops being a significant contributor in the equilibria.
The following is multiple choice question (with options) to answer.
A thing may be changed on a chemical level after | [
"putting it in a tree",
"making it pay rent",
"setting it on fire",
"looking at it through a mirror"
] | C | chemical reactions cause chemical change |
OpenBookQA | OpenBookQA-2074 | java, swing, audio, music
System.out.print(" (" + finalNote + ")\n");
playNote(finalNote, Integer.parseInt(instrumentChoice.getText()));
}
}
There are at least three things going on here...
public void actionPerformed(ActionEvent e) {
Object source = e.getSource();
if (source instanceof JButton) {
JButton but = (JButton) source;
String note = but.getText();
String octave = octaveChoice.getText();
String instrument = instrumentChoice.getText();
int finalNote = (Integer.parseInt(octave) * 12) + extendedNote.indexOf(note);
int finalInstrument = Integer.parseInt(instrument);
playNote(finalNote, finalInstrument);
}
}
You've got the ActionListener, which is reading Strings out of awt, you've got a Parser, which knows how to turn those strings into notes and instruments, and you've got a Player that knows how to turn notes and instruments into sounds.
This separation is important, because you should be able to do test that the parser does the right thing without assembling the entire UI for it. You should be able to replace this player with another one that uses a different set of magic numbers to generate ShortMessages.
The following is multiple choice question (with options) to answer.
A person wants to play a song out yet lacks an instrument, so they can | [
"think about a piano",
"hold a paper towel tube",
"flick a taut rubber band",
"look at a table"
] | C | An example of playing a musical instrument is hitting the keys of a piano |
OpenBookQA | OpenBookQA-2075 | laser, glass, laser-interaction, fluorescence
Title: Mechanism causing red fluorescence from green (532nm) laser in household glass Background / Experiment
I was surprised by this toot by @gigabecquerel, where the author shows red fluorescence in the thick bottom of a (drink) glass when exposed to a cheap consumer-grade green laser pointer laser. They also verified that it's not some kind of selective scattering or such of a minor red component in the original laser, by using a diffraction grating to definitely select a monochromatic beam.
I was able to reproduce these results (no filtering, though).
I was able to show this red fluorescence for
Thick-walled drinking glasses
Thin-walled -"-
Glass jugs
Glass bottles
The following is multiple choice question (with options) to answer.
A laser produces a light source, which may be useful in | [
"cleaning a glass",
"juggling stones",
"playing with felines",
"doing the dishes"
] | C | a laser is used for producing light |
OpenBookQA | OpenBookQA-2076 | 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 person has a hot dish from the oven that they have left on the counter. After a few minutes, they place that dish into a sink full of cold water. The dish | [
"warms",
"freezes",
"dies",
"chills"
] | D | if a hot object is touches a cold substance then that substance will likely cool |
OpenBookQA | OpenBookQA-2077 | radiation
You see similar things happening here. The metal rod at the top of the lamp acts as a capacitive ground - given the very high voltage, a tiny charge will flow from the tip of the filament to the rod. There is a small amount of gas in the tube which is ionized and gives rise to the light you see. The electrons eventually bombard the metal "anode" and produce Bremsstrahlung - note that without the metal, you were getting a glow and no reading on the Geiger counter. There is a similar demonstration online which is more convincing in its use of conventional materials, but which otherwise shows many of the same phenomena.
It is almost certainly very inefficient. Most of the energy in an X-ray tube is converted to heat as the electrons burrow too deeply into the tungsten target for their radiation to escape- apart from the fact that only the most violent deceleration produces X-rays with high enough energy to penetrate the bulb and be detected.
I noticed that when the "alpha window" was removed, the reading in your video went up. Since there was also a biscuit tin and glass bulb in the way I suspect there was a lot more low energy radiation generated than was detected. Good stuff for skin cancer.
The experiment as shown should not be repeated. Not only were the HV precautions extremely poor, but so were the radiation safety precautions. Please don't try this at home...
The following is multiple choice question (with options) to answer.
A large source of heat can be seen in the | [
"sky",
"cave",
"ocean",
"tree trunk"
] | A | the sun is a source of heat called sunlight |
OpenBookQA | OpenBookQA-2078 | zoology, experimental
Title: Fish "coming back to life" after being frozen I've encountered a clip on Youtube showing a goldfish thrown in liquid nitrogen and immediately after to normal water and swimming normally. In the explanation to the clip it says:
For everyone that is worried about the goldfish, it survived and was perfectly fine until we fed him and a few of his friends to our turtles. (Which is what they were bought for in the first place!)
I am wondering now as to several issues.
If the goldfish wasn't fed to the turtles and was allowed to live out its life, would it suffer any long term damages from the act?
Is time an issue here, if the fish was kept frozen for a longer time, would it suffer more damage and would it be able to be revived?
Is the size and nature of the fish's body a factor? Would a larger animal or an animal with better resistance to frost that would take more time to completely freeze have damage due to gradual freezing of body and systems?
Does the fact that fish have cold blood affect the result of the experiment? I have no idea what's the real reason for the survival of the poor fish, but I would guess this is all in the timing. I know for certain ;-) that one can submerge a hand in liquid nitrogen for a short time or in general one can pour liquid nitrogen on the skin with no harm done whatsoever.
The reason is that the difference in temperature that interface (-180 deg C or so for liquid nitrogen and 20-30 for the skin surface) is so large that nitrogen vaporizes instantly and does not penetrate/affect the tissue. The demonstrator could have pulled the fish with bare hands.
I think that for the goldfish the time was too short and while it was cooled/shocked a bit, it might have been too short to do any serious damage. But -
As a scientist, I can't help but notice that we don't really know the condition of the fish before or after the liquid nitrogen 'treatment'. We only see it flapping for a few seconds when back in water. I wonder what happened to the eyes and the mouth, both quite sensitive tissues for such a shock. Also, the water the fish was in was a factor probably, providing additional buffer between the fish and the liquid nitrogen.
Last but not least, the ethical committee quite certainly did not approve that demonstration.
The following is multiple choice question (with options) to answer.
Which of the following can die if it gets too cold? | [
"iced coffee",
"snow",
"bears",
"Pluto"
] | C | if a living thing becomes too cold then that living thing will die |
OpenBookQA | OpenBookQA-2079 | atmosphere, ocean, hydrology, climate-change
Comment: I strongly endorse the use of wind and hydropower as sources of energy over the further use of fossil fuels. However, I still think it is important to do research into the actual renewability of presumed-renewable energy sources, as we don't want to end up with another fossil fuel-type situation, in which we become aware of dependency on these energy sources and their malignant environmental side-effects long after widespread enthusiastic adoption. Electricity from waves, from hydro (both run-of-river and storage) and from wind, are all indirect forms of solar power. Electricity from tides is different, and we can deal with that in a separate question. Global tidal electricity generation is not yet at the scale of gigawatts, so it's tiny for now.
Winds come about from the sun heating different parts of the planet at different rates, due to insolation angles, varying cloud cover, varying surface reflectivity, and varying specific heat of surface materials. Temperature differentials create wind currents.
Waves come about from wind, so they're a twice-indirect form of solar power.
Sunlight on water speeds up evaporation, lifting the water vapour into clouds, giving them lots of gravitational potential. That rain then falls, sometimes onto high land, from where it can be gathered into storage reservoirs that are tapped for electricity, or where it flows into rivers that are then harnessed in run-of-river hydro.
How much power is there? Well, the insolation from the sun is, at the outer boundary of the Earth's atmosphere, at an intensity of about 1400 Watts per square metre. The Earth's albedo is roughly about 30% - i.e. on average about 400 Watts are reflected back into space, giving an average irradiation into the Earth of about 1000 Watts per square metre. Picture the Earth's surface as seen from the Sun: wherever the Earth is in its orbit on its own axis, and around the Sun, the Sun sees a disc that has the Earth's diameter, so the surface area exposed to the Sun is just $\pi$ times the square of Earth's radius, which is about 6 300 kilometres.
So the incoming solar radiation is $1000 \times 6,300,000^2 \times \pi \approx 125 \times 10^{15} \rm \ W$
The following is multiple choice question (with options) to answer.
A person needing to use a renewable resource would consider all with the exception of | [
"solar energy",
"water source",
"hydrocarbon gas mixture",
"wind power"
] | C | natural gas is a nonrenewable resource |
OpenBookQA | OpenBookQA-2080 | thermodynamics, temperature, everyday-life, phase-transition, humidity
Title: Steam from a cup of coffee I observed that, in winter there is more visible steam from a cup of coffee than in summer. Is there any phenomenon taking place here. The amount of water that air can take up before the water creates fog or visible steam depends on temperature. The colder the air, the less water it needs to create fog/steam. It is the same principle when hot air rises, for example when pushed up a mountain and then it starts to cool down drastically --> It will rain.
For more have a look at: Relative humidity in https://en.wikipedia.org/wiki/Humidity
The following is multiple choice question (with options) to answer.
A cloud could form in a home if the conditions were right and steam could | [
"gather",
"file",
"burn",
"stem"
] | A | clouds are formed by water vapor rising and condensing |
OpenBookQA | OpenBookQA-2081 | $7|61$ gives $61=7\cdot 8 +5$
He would have 5 cows left over. So 61 can't be an answer
5. Hello, swimalot!
A cowboy was asked how many cows were on the ranch.
He replied that he was unsure, but he knew that when he counted them
by twos, threes, fours, fives, or sixes, he always had one left over.
When counted by sevens, he had none left over.
What is the smallest number of cows on the ranch?
Let $N$ = number of cows on the ranch.
The LCM of 2, 3, 4, 5, 6 is $60$
. . Hence: . $N \:=\:60a + 1$ ... for some integer $a.$
Since $N$ is divisible by 7: . $60a + 1 \:=\:7b$ ... for some integer $b.$
Solve for $b\!:\;\;b \:=\:\frac{60a+1}{7} \;=\;8a + \frac{4a+1}{7}$
Since $b$ is an integer, $4a + 1$ must be divisible by 7.
The first time this happens is: $a = 5$
Therefore: . $N \;=\;60(5)+1 \;=\;\boxed{301}$
6. Originally Posted by TheEmptySet
we know that it needs to be a multiple of 7 from all of the other clues we know it can't be even (because two can't divide it) and the last digit need to be a one because when divided by 5 it needs one left over.
here is our list,
56,63,70,77,84,91
If you check all the other conditions you will see that they hold.
I hope this helps.
Hello Tessy
91 doesn't work for ... four
91=88+3
7. You could use the Chinese Remainder Theorem, Topsquark has a lovely example in post #5 here http://www.mathhelpforum.com/math-he...nt-modulo.html
8. I will do the Chinese Remainder Theorem for you:
The following is multiple choice question (with options) to answer.
A person feeds their cows corn. They grow an acre of corn each year for the herd. They add another thirty cows to their herd, so they | [
"burn the corn",
"grow less corn",
"plant several acres",
"remove some cows"
] | C | as the use of a crop increases , the amount of crops planted will increase |
OpenBookQA | OpenBookQA-2082 | radiation
Title: Why can sunlight heat an object on the other side of glass? Q1. Why can sunlight heat an object on the other side of glass, but normal light from a CFL or Incandescent Light bulb can't.
Q2. Do they make a light bulb that can do this? I need to increase the tempature and objects inside a glass tank.
I'm fully aware of bulbs like the Floureon Ceramic Infrared Bulb Heat Emitter Reptile Lamp. Different types of "glass" transmit and block different types of radiation. When astronomers are making infrared instruments and they need to place a window in the instrument, they use sapphire. Ordinary glass, similar to borosilicate in the plots on this page, blocks infrared radiation that we normally think of as heat.
The way the sun heats up objects behind glass is by pouring enough visible and UV light through the glass to do the heating. The glass then blocks the infrared radiation from escaping, causing the heat to build up.
The following is multiple choice question (with options) to answer.
Which object would be best at heating up in the sunlight? | [
"a clear solar panel",
"a black solar panel",
"a white solar panel",
"an invisible solar panel"
] | B | absorbing sunlight causes objects to heat |
OpenBookQA | OpenBookQA-2083 | optics, visible-light
Title: Any scientific basis behind Thoreau's Stacked Shadows? In Walden Henry David Thoreau states,
Sometimes, when the ice was covered with shallow puddles, I saw a double shadow of myself, one standing on the head of the other, one on the ice, the other on the trees or hillside.
This was in a section where Thoreau was simply surveying the pond and describing things matter-of-factly, so I don't think it is meant to come across as symbolism.
I was hoping to find a possible explanation for this. Since he mentions this to happen only when shallow puddles are present, Perhaps it's a combination of reflection and refraction? Interesting question!
Consider the sketch below. Imagine that the ice is covered completely by water, making the surface reflective. If Thoreau is standing on the ice, the sunlight blocked by his body will form a shadow on the surface of the water.
From the locations on the ice, where his shadow is present, light will NOT be reflected on to the steep hillside in front of him. Therefore, there will be a Thoreau-shaped region on the hillside, where less light arrives - a secondary shadow!
As can be seen, Thoreau will observe two shadows seemingly "standing" on top of each other - one on the water and the other on the hillside.
EDIT: Looks like I was a bit to quick posting this drawing. The secondary shadow on the wall will actually be upside down!
The following is multiple choice question (with options) to answer.
John's shadow looks like it's directly underneath him. What time is it? | [
"9am",
"12pm",
"12am",
"2pm"
] | B | the sun is located directly overhead at noon |
OpenBookQA | OpenBookQA-2084 | fluid-dynamics, pressure
There are other sources of energy which could conceivable be used in a siphon-like experiment. One possible candidate is surface tension.
If the surface tension of a fluid is strong enough then it might in principle be able to overcome gravity. You would need a liquid that can form large drops with height of similar size to the size of the siphon. Water has a high surface tension compared with most liquids, but I don't believe it would work in a normal-sized apparatus, except perhaps in micro-gravity.
This device would be driven by the liquid trying to reduce its total surface area. The direction of flow would depend on how much liquid was already in each container, the relative heights of the liquid in the reservoirs, the shapes of the reservoirs and the amount of attraction between the liquid and the containers and tube.
The following is multiple choice question (with options) to answer.
A viscous liquid found underground can be made to create something that | [
"feeds your dog",
"foretells the future",
"tastes like milk",
"makes cars move"
] | D | oil is a source of gasoline |
OpenBookQA | OpenBookQA-2085 | genetics
Title: Arguments against incest Incest is forbidden in most countries because if there is a genetic disease in the family the child of a incestuous relationship will be at least holder of the gene of that disease. But lets say the members of a family dont have a genetic disease and are not holders of any gene related to a genetic disease then theoretically would a child of a incestuous relationship not suffer from diseases by birth? Incest doesn't necessarily mean that the partners are having unprotected sexual intercourse. It simply means sexual intercourse between closely related member of a family. In case of protected sexual intercourse, it doesn't matter whether or not the family has history of some genetic disorder.
But let's say they are practicing unprotected sexual intercourse. In that case, it does depend on the genetic history of the family. If either or both of the parthers has gene that result in a disorder, then thier offspring who gets that gene expressed in his/her body will suffer from that genetic disorder. And if it is not expressed, they become a carrier for that gene.
Now, coming to the case you mentioned, Yes, if neither of the partner have gene that causes certain genetic disorder, then the offspring will not suffer from the said gentic disorder.
But it only works if there's a no history of incest wihtin that family. In case they do have history of incest within thier family, they are likely to suffer from inbreeding depression. Inbreeding depression 'exposes' deleterious recessive genes by making them homozygous. This causes drop in fitness of the offspring and reduced fertility. Increased homozygosity is what causes issue, which increases chances of a harmful recessive gene getting expressed.
So it's not a big worry, if they don't have any such gene that cause obvious harm by resulting in a certain genetic disorder. But continuous incest in family may result in problems later on.
Anyway, it is possible to be able to determine compatibility of two people by checking thier genetic information [we may become even more advance in near future]. We can selectively edit a gene to make it so that it won't be present in the offspring. Gene editing at advance level will get really popular.
The following is multiple choice question (with options) to answer.
A parent may genetically share with a child of their own conception | [
"many freckles",
"new songs",
"big pizzas",
"silly faces"
] | A | reproduction is when an organism passes genetic information from itself to its offspring |
OpenBookQA | OpenBookQA-2086 | That would be a total of 5x30 + 3x40 + 2x60 = 390 plants (with an arbitrary factor that we'll set to 1 without loss of generality).
The amount of highbush is 5x30 = 150.
The amount of lowbush is 3x40 = 120.
The amount of hybrid is 2x60 = 120.
If the opossums didn't care, they would likely eat blueberries in this ratio (null hypothesis H0).
The total that we have observed the opossums to eat is 5% x 150 + 10% x 120 + 20% x 120 = 43.5 plants.
They eat 5% large, which a corresponding fraction of 5% x 150 / (5% x 150 + 10% x 120 + 20% x 120) = 17%
They eat 10% low for 10% x 120 / (5% x 150 + 10% x 120 + 20% x 120) = 28%
They eat 20% hybrid for 20% x 120 / (5% x 150 + 10% x 120 + 20% x 120) = 55%.
Checking... yes the total is 100%.
What we see is that the opossums prefer hybrid by far.
Small blueberries are their second choice.
Last edited:
#### anemone
##### MHB POTW Director
Staff member
Hi anemone!
What do you mean by the symbol E?
Anyway, you've found that the opossums eat 45.8% large and 54.2% small for a total of 100%.
But... what happened to the hybrid blueberries?
By the symbol E, I meant the blueberries (all 3 types of them) that are eaten by opossums...
That would be a total of 5x30 + 3x40 + 2x60 = 390 plants (with an arbitrary factor that we'll set to 1 without loss of generality).
The amount of highbush is 5x30 = 150.
The amount of lowbush is 3x40 = 120.
The amount of hybrid is 2x60 = 120.
If the opossums didn't care, they would likely eat blueberries in this ratio (null hypothesis H0).
The following is multiple choice question (with options) to answer.
Which of the following is likely to eat berries? | [
"a sparrow",
"a lobster",
"a tiger",
"a walrus"
] | A | birds sometimes eat berries |
OpenBookQA | OpenBookQA-2087 | cell-biology, organelle
Title: Univocal identifying of a plant cell We yesterday got our biology-exams back and there's one exercise where I don't agree with my teacher. However, since he is the expert and not me, I need the support of external sources, i.e. experts in order to justify my statement.
Now in the exercise, we first had to identify the parts of a cell (which was shown in form of an image) and then in part b) reason whether it was an animal or plant cell.
I had identified a chloroplast and a vacuole and stated that the only cell with this organelles was the plant cell. My teacher answered that I had missed the fact, that the cell had also a cell wall (which is indeed a difference between plant and animal cells).
My question is
Is the fact that the cell had a cell wall necessary in my argumentation, i.e. are there other cells having chloroplasts and a vacuole without being a plant cell?
Could you provide a source which supports, or doesn't support my statement so that I can show it to my teacher?
Thanks in advance Your teacher is right, chloroplasts and vacuoles are not sufficient to define a plant cell.
Amoeba have both chloroplasts (McFadden et al, PNAS, 1994) and vacuoles (Day, J. Morphology, 1927) but they are not plants - and they do not have a cell wall.
Sea slugs eat algae and can "steal" their plastids and keep them working for weeks/months, effectively becoming photosynthetic animals for a while. This is called kleptoplastidy (Pillet, Mob. Genet. Elements, 2013).
The following is multiple choice question (with options) to answer.
Chloroplasts need to be collected, so scientists gather up | [
"carnations",
"sparrows",
"stones",
"feathers"
] | A | a plant cell contains chloroplasts |
OpenBookQA | OpenBookQA-2088 | ecology, population-dynamics, ecosystem, antipredator-adaptation, predation
I would also like to talk about other things that might be of interest in your model (two of them need you to allow evolutionary processes in your model):
1) lineage selection: predators that eat too much end up disappearing because they caused their preys to get extinct. This hypothesis has nothing to do with some kind of auto-regulation for the good of species. Of course you'd need several species of predators and preys in your model. This kind of hypothesis are usually considered as very unlikely to have any explanatory power.
2) Life-dinner principle. While the wolf runs for its dinner, the rabbit runs for its life. Therefore, there is higher selection pressure on the rabbits which yield the rabbits to run in average slightly faster than wolves. This evolutionary process protects the rabbits from extinction.
3) You may consider..
more than one species of preys or predators
environmental heterogeneity
partial overlapping of distribution ranges between predators and preys
When one species is absent, the model behave just like an exponential model. You might want to make a model of logistic growth for each species by including $K_x$ and $K_y$ the carrying capacity for each species.
Adding a predator (or parasite) to the predator species of interest
... and you might get very different results.
The following is multiple choice question (with options) to answer.
As rabbits in a county die off, foxes will | [
"live longer",
"boom in population",
"do the same",
"eat trees"
] | C | as population of prey decreases , the population of predators will decrease |
OpenBookQA | OpenBookQA-2089 | geology, geothermal-heat, mapping, natural-conditions, underground-water
If you are in a desert climate, you may be able to do something similar on a smaller scale. Under a calm clear sky, you can often get frost on the side of an insulator facing the dark sky at night. Modifying this idea, create a large bottom insulated surface coated with a good IR emitter (Titanium dioxide white is one such.) , and run shallow water over it. If you can routinely get 30 C colder than day time air temps, then you only have to store a few days worth of coolth instead of a years worth.
You can make the system above colder by pre-chilling the water with an evaporative cooler
Edit: One source claims 1 degree F per 30 feet starting at around 100 feet. Temperatures above this
however are highly variable from water movement.
The following is multiple choice question (with options) to answer.
At 30 degress fahrenheit, water is | [
"hot",
"solid",
"quenching",
"gaseous"
] | B | freezing point means temperature at which a liquid freezes |
OpenBookQA | OpenBookQA-2090 | newtonian-mechanics, estimation
Would the rock have created a seismic event of its own (if so, how large)?
Would the rock have created a crater? The energy of the rock at the time of hitting the earth is mgh.
No rock we know of is going to be able to survive this collision with out breaking into pieces.
Non the less it will be a big impact and depending on the geology of the location it hits a variety of reactions scenarios can happen.
If the soil is aggregate of silt and sand and gravel, it would part into several shear rupture sections which look like slices of shell pattern surfaces starting from the bottom surface of the rock and turning up exiting the earth surface a few hundred yards outside of the impact zone and probably even eject some material out like a bomb crater. This scenario will have shakes that could be recorded miles away.
The calculation of how much of the momentum of rock will be shared with the shear material and accelerating them will be involved but not impossible.
If the geology of the impact area is of very low bearing like mostly silt and loose clays, the rock my lose most of its kinetic energy by just sinking into the dirt mostly with a giant humph with a cloud of dust rising.
If the geology is hard or rocky with the 'optimal' amount of mass and resilience it could create a substantial earthquake by resonating with the impact.
The following is multiple choice question (with options) to answer.
Rocks folded over and over which developed | [
"tall areas",
"wet rivers",
"large trees",
"grassy yards"
] | A | the Himalayas were formed by rock folding |
OpenBookQA | OpenBookQA-2091 | solutions, vapor-pressure
Title: If some particles of liquid in a solution convert to vapour then why can't some liquid particles convert to solid? I was reading about the vaporisation of liquid when I came across the following statement.
The average energy of the particles in a liquid is governed by the
temperature. The higher the temperature, the higher the average
energy. But within that average, some particles have energies higher
than the average, and others have energies lower than the average.Some
of the more energetic particles on the surface of the liquid can be
moving fast enough to escape from the attractive forces holding the
liquid together. They evaporate.
Now if some particles have energies lower than the average, then why don't they convert into solids in the same way the particles with higher energies convert to gases.
If we cover a vessel filled with water with a plate, after some time, we observe droplets of water accumulated at the plate because of vaporisation of water. Why don't we observe any changes that show liquid particles converting to solid? If water molecules go into the gas phase from the liquid then they are in a different phase. But water molecules go into the gas phase one at a time. If there are the same number of water molecules leaving the liquid as coming into it then the atmosphere above the liquid would have 100% humidity and be in equilibrium with the liquid.
Now if some small number molecules of water happen to line up to form an ice crystal within the water itself what happens? Such an ice crystal is thermodynamically unstable and then "melts" within the liquid phase. Since the whole process takes place in the liquid phase it is virtually undetectable.
Now you also have to realize that form ice crystals big enough to detect visually requires more than a handful of molecules. You'd need billions of billions of molecules. That is just a statistical impossibility.
The following is multiple choice question (with options) to answer.
Glass can become a liquid if | [
"it is baked",
"it is frozen",
"it is dampened",
"it is dyed"
] | A | melting point means temperature above which a solid melts |
OpenBookQA | OpenBookQA-2092 | algorithm, go, concurrency, dining-philosophers
// reserve a slot in the channel for eating
// if channel buffer is full, this is blocked until channel space is released
pPhilo.host.requestChannel <- pPhilo
pPhilo.numEat++
fmt.Printf("starting to eat %d for %d time\n", pPhilo.idx, pPhilo.numEat)
time.Sleep(time.Millisecond)
fmt.Printf("finishing eating %d for %d time\n", pPhilo.idx, pPhilo.numEat)
pPhilo.rightCS.mu.Unlock()
pPhilo.leftCS.mu.Unlock()
wg.Done()
}
}
func main() {
var wg sync.WaitGroup
host := Host{
eatingChannel: make(chan *Philo, numEatingPhilo),
requestChannel: make(chan *Philo),
quitChannel: make(chan int),
eatingPhilos: make(map[int]bool),
}
CSticks := make([]*ChopS, numCS)
for i := 0; i < numCS; i++ {
CSticks[i] = new(ChopS)
}
philos := make([]*Philo, numPhilo)
for i := 0; i < numPhilo; i++ {
philos[i] = &Philo{idx: i + 1, numEat: 0, leftCS: CSticks[i], rightCS: CSticks[(i+1)%5], host: &host}
}
go host.manage()
wg.Add(numPhilo * eatTimes)
for i := 0; i < numPhilo; i++ {
go philos[i].eat(&wg)
}
wg.Wait()
host.quitChannel <- 1
}
The following is multiple choice question (with options) to answer.
Overeating | [
"causes massive weight loss",
"causes the number on the scale to go up",
"boosts the immune system",
"causes the number on the scale to go down"
] | B | as the amount of food an animal eats increases , the weight of that animal will increase |
OpenBookQA | OpenBookQA-2093 | species-identification, zoology, bone-biology, bone
Title: What is this bone from? This object showed up on my fire escape in New York city. It appears to be some kind of bone. It's a bit smaller than an adult human hand. What animal is it from? Given the size and thin/elongated ilia as well as the urban location, I think a domestic cat and/or a raccoon are likely candidates. I'm leaning toward cat.
Cat pelvis:
VCA Hospitals
Ventral view of domestic cat pelvis; Source: BoneID
Raccoon Pelvis
Anterior view of raccoon pelvis; Source: BoneID
I'm not an expert in differentiating these two species' bones. I will note that your specimen is more or less in between the sizes of these two species. Your size is probably closer to the raccoon, but a cat is just more likely given the location.
The most noticeable trait that stands out to me is the size/pointedness of the ischial tuberosity, which better matches that of the cat.
The following is multiple choice question (with options) to answer.
A person approaching a dog from across a street can note that the dog | [
"looks tiny when nearer",
"is minuscule in person",
"looks more sizable after approaching",
"looks smaller up close"
] | C | if an object is close then that object will appear large |
OpenBookQA | OpenBookQA-2094 | 4. A contractor estimated that his 10-man crew could complete the construction in 110 days if there was no rain. (Assume the crew does not work on any rainy day and rain is the only factor that can deter the crew from working). However, on the 61-st day, after 5 days of rain, he hired 6 more people and finished the project early. If the job was done in 100 days, how many days after day 60 had rain?
(C) 6 - rains for 5 days from day 56-60. So 10 guys worked for 55 days and accomplished half of the work. If 6 more guys are added to the job then the rate is 16/1100. (since one man's rate is 1/1100). Half the job left means 550/1100 is left. Therefore 550/16 = 34.375 days of more work. Since there were 40 days between day 60 and job completion, it must've rained for 40-34.375 = 5.625 or ~6 days. (I'm not sure if this is correct)
5. If s and t are positive integer such that s/t=64.12, which of the following could be the remainder when s is divided by t?
(E) 45 - 64.12 = 6412/100 or 1603/25. 1603/25 gives a remainder of 3, 3206/50 gives remainder of 6 and so on ..pattern = factors of 3. so to get remainder of 45, we multiply everything by 15: 1603*15/(25*15) = 24045/375.
The following is multiple choice question (with options) to answer.
A storm ravages a town for a week straight, complete with deluges of rain. If someone in that town needs a source of water, it is | [
"everywhere",
"missing",
"in short supply",
"rare"
] | A | as the amount of rainfall increases in an area , the amount of available water in that area will increase |
OpenBookQA | OpenBookQA-2095 | fusion, renewable-energy
An energy "breakthrough" would be a loaded development. We already use lots of energy, and if we found it economic to use more we probably would. The last breakthrough shift in our ability to exploit energy resources rocketed the entire planet into a new geological era, the Anthropocene. We called this change the industrial revolution. Some obscure project that ARPA-E funded with $500,000 could cause the next industrial revolution. The implications of such a change would probably be beyond any of our imaginations.
The following is multiple choice question (with options) to answer.
A change on our planet could be | [
"cats eating mice",
"forests becoming lakes",
"clouds raining",
"deer running"
] | B | An example of a change in the Earth is an ocean becoming a wooded area |
OpenBookQA | OpenBookQA-2096 | species-identification, botany
Title: Identification of a plant Please help me to identify this plant
The plants can be found on italian balconies and I would like to buy one, but I do not know what I should look for.
The habit of the plant is trailing. This is likely to be a stone plant (Aizoaceae), depending on habit, it could well be the ice plant (Carpobrotus edulis). Stone plants are a quite diverse family of succulents from southern Africa, but are widespread throughout the western world as stabilizers of sand-dunes and in gardens as they are very tolerant of lack of watering and high salinity.
Ice plants are very common in the Mediterranean region, having become an invasive pest on much of the coastline.
If it is ice plant, then you can sub-cultivate it by taking a small part of the plant, usually leaves with a bit of stem, but even a leaf by itself may work, and placing it in water or on sandy soil. With regular watering, it should grow roots and then be plantable.
Apparently the leaves of ice plant are edible (hence the edulis part of the name), similar to Aloe I suspect.
The following is multiple choice question (with options) to answer.
An iris may have trouble thriving in an arid location, or even in a frozen location, because it needs | [
"to be dried and preserved",
"a certain climate to boom",
"a bucket of ice water",
"to be buried in snow"
] | B | a plant requires a specific climate to grow and survive |
OpenBookQA | OpenBookQA-2097 | entomology, ethology, habitat
Title: Preferred criteria for new bee colony location As a human I want a house with a roof, indoor plumbing, bug free, and make my wife happy. I don't want to drive too far to work, and it has to be well-suited for offspring.
What are the criteria that define a "good spot" for a new location for honey bees. I'm sure it involves water, shade, access to nectar, and defensibility, but I don't know any of the details.
Has anyone ever made measures of this? Beekeepers? Apiologists? What are the things bees think are important, and what values of those do they think are "best"? According to Thomas Seeley, in his book, Honeybee Democracy, he gives the following as important criteria for honeybees when selecting a nest site when a bee colony moves to swarm:
Larger volume (the minimum nesting capacity was found to be around 14 liters with more preference to nests with a capacity of approximately 30 to less than 100 liters)
Relatively small entrance (10 to 30 centimeters squared)
Nest with the entrance located near the floor of a tree cavity
Direction of the nest entrance (south facing for thermoregulation during the winter)
Nest height (preference given to higher nests for colony defense)
Remnants of previous honeycombs (saves work and energy in building the nest structure)
Interestingly enough, bees did not necessarily display a preference for the shape of the entrance, the shape of the nest, the draftiness or dryness of the nest cavity (they are able to plug and waterproof nests).
Flower/nectar/food availability is not necessarily a direct factor as this changes quite frequently throughout the seasons and honeybees are not able to leave their honey stores (which are necessary to sustain the colony throughout the winter) or take them with them every time the colony has trouble finding food. Honeybees have a complex and efficient system for optimized location and sharing of food sources, therefore distance is not as large a factor.
The following is multiple choice question (with options) to answer.
A bee will be able to make a hive of golden liquid if they have access to | [
"tumbleweeds",
"plastic flowers",
"products of flowers",
"painted colors"
] | C | bees convert nectar into honey |
OpenBookQA | OpenBookQA-2098 | everyday-chemistry, cleaning, minerals
Once you've got the crystal to the cleanliness you're happy with, you can polish it with powdered polish and a cloth, given time.
If instead of nice, angular crystals you're just trying to produce something like a smooth, rounded stone, after cleaning with water you can use a series of sandpapers (start at 60-80 grit and work up to ~400 grit) and polish to gradually smooth, then polish the stone by hand. This will clear away any deposits, but it will also change the surface of the stone itself. That might be acceptable to you if you've got something like a quartz river rock, and it will make a very nice end product. Take care to keep the stone wet while working, you don't want to breathe in rock dust if you don't have to.
The following is multiple choice question (with options) to answer.
What would be a source of the smoothest rocks? | [
"a riverbank",
"the cliffs",
"the desert",
"the mountains"
] | A | contact between rocks over long periods of time causes rocks to smooth |
OpenBookQA | OpenBookQA-2099 | angular-momentum, momentum, conservation-laws, collision, moment
This explanation has been misinterpreted:
If cutting off the zombie's head is an inelastic collision that
requires the greatest transfer of momentum/energy, then clearly this
will be achieved if the sword stops moving completely at the end of
the stroke - if the sword keeps moving it still has energy / momentum
that wasn't used to chop off the head.
As you can clearly see in the right diagram the sword stops moving at the hilt, at the side opposite to the CoP, because the linear velocity (to the right) and the rotational velocity (to the left) have equal value and opposite direction, while the tip of the sword keeps rotating and would also move to the right in a straight line if it were not held tight.
besides that
It is possible to put the center of percussion at the tip of the sword
- I believe this happens when you hold the sword at 5/12th of the way along the length.
you can easily verify that it would be practically impossible to put the CoP at the end of the sword.
It is probably opportune to conclude the explanation reminding that...
The sweet spot on a baseball bat is generally defined as the point at
which the impact feels best to the batter ... Although it has long been
believed the center of percussion and the sweet spot are the same,
recent practical observations have indicated that the point many
batters feel is "sweetest" corresponds to a pivot point in the arm,
beyond the handle of the bat
The CoP and soft spot are important in baseball because even the least swing of the bat at the wrist of the batter makes a great difference in the trajectory of the ball. But there is no chance that the bat or the sword can fly off the hand.
In conclusion, hitting a head with the point of a sword (roughly)at one third from the center, at 66.6 cm from the hilt makes only the wrist of the fighter feel more comfortable: the tip of the sword behaves in the regular way (the collision is obviously always inelastic since both bodies are not elastic) and you are only subtracting precious momentum to the blow.
As I said in my comment: ".. the only advantage you have hitting at the sweet spot is that you only no backlash at the wrist, but if you have a firm grip there is no problem and the sword has more momentum. If you cannot hold your sword,... don't fight "
The following is multiple choice question (with options) to answer.
A guy can hit another person if he | [
"drops a rock",
"lifts a dog",
"picks up shoes",
"sings a song"
] | A | An example of hitting something is dropping an object onto that something |
OpenBookQA | OpenBookQA-2100 | the-sun, orbit, planet, earth
Is the spiraling movement caused by sun movement (on its path shown
above) where the sun is dragging the earth (and other planets)?
No, the Sun's and the Earth's mutual gravity cause the Earth to rotate around the Sun. The Milky Way's gravity causes our Solar System to revolve around the galactic center. The Sun and the Earth are on the same plane and moving through the galaxy together. The Earth would still rotate around the center of the Milky Way if the Sun magically disappeared.
Does the earth go in front of the sun then back, then fourth and back
like it is shown on the video? I see both the sun and earth racing
with each overtaking the other over and over. Is this assumption true?
In this manner, would earth, at one point in time, be closer to the
destination where the solar system is heading (I think they call the
destination Vega) than the sun?
If you consider a plane tangent to the Sun's velocity vector, then the Earth will pass across that plane twice per year, appearing "in front of" and then "behind" the Sun. This is simply a geometric result since the Earth and Sun share another plane. I wouldn't call any future position of the Solar System a "destination" without evidence the Solar System was sentient, but I am not a philosopher.
I am working on a poetry piece. If I mention that earth and sun are
locked in a never ending race with each taking the lead (earth moving
in front of the sun's path / winning) and earth actually dropping out
of the race (spiraling/moving out the race and falling behind), that
they are destined to never meet (collide), would I be correct?
We haven't ruled out the possibility that the Sun may someday envelope the Earth: What will "the Earth being consumed by the Sun" look like?. Also, the Earth isn't likely to leave its orbit before that time, but the Solar System is chaotic on long time scales. However, your poem would be consistent with current models, and we (humans) don't conclusively know how the Solar System will end. So my two cents is that your poem doesn't contradict modern astronomy. Besides, what's the use of a poetic license if you don't use it?
The following is multiple choice question (with options) to answer.
The earth makes its way around the sun. Because of the constant rotation, the appearance of these is unlikely to be regular. | [
"the moon",
"the oceans",
"celestial bodies",
"the sun"
] | C | the Earth revolving around the sun causes stars to appear in different areas in the sky at different times of year |
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