source string | id string | question string | options list | answer string | reasoning string |
|---|---|---|---|---|---|
OpenBookQA | OpenBookQA-3001 | zoology, ethology, behaviour, psychology, death
I can't prove it to you, but I know that my Beagle had a rich emotional life. I know this because I spent huge amounts of time with him. He was a close friend of mine. I would just as soon question whether my wife has real emotions as my dog. I can't prove that my wife's emotions are real either, but I don't have to. It would be silly to assume that everything she shares with me is some sort of evolutionary programming, and not real emotion. Now, when I extend this to cetaceans, I must admit that I don't have any friends in those circles. So I can only guess.
The following is multiple choice question (with options) to answer.
Animals the exemplify relationship behaviors are | [
"air",
"space",
"metal",
"killdeer"
] | D | An example of a reproductive behavior is salmon returning to their birthplace to lay their eggs |
OpenBookQA | OpenBookQA-3002 | 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.
What are some birds? | [
"people",
"creature eaters",
"fish",
"solar"
] | B | some birds are predators |
OpenBookQA | OpenBookQA-3003 | thermodynamics, forces, water, estimation, freezing
Here, a phase diagram for water is useful. The discussion in Powell-Palm et al.'s "Freezing water at constant volume and under confinement" includes a volume–temperature phase diagram:
From this, we can predict the equilibrium response when heating or cooling water at constant volume (by moving vertically) or compressing or expanding water at constant temperature (by moving horizontally). We find that at constant volume (moving vertically downward from 0°C and 1 g/cc), over 200 MPa and 20°C undercooling is required* to get even a 50% slush of water and ice.
Let's zoom out a little. From Powell-Palm, "On a temperature-volume phase diagram for water and three-phase invariant reactions in pure substances," we find that 209.9 MPa is ultimately required* for complete solidification, into a two-phase region (at equilibrium) of ice-Ih (ordinary ice) and ice-III:
(Note that "0.00611 MPa" should read "0.000611 MPa"—the authors missed a zero.)
We can interpret this as the compact structure of ice-III providing a solution to the problem of ice-Ih being anomalously voluminous. We find from the temperature–pressure phase diagram of water that this ice-III nucleates (at equilibrium) upon cooling to 251 K, or -22°C:
The following is multiple choice question (with options) to answer.
Freezing point is best represented by | [
"ice sculpture",
"glass of water",
"flowing rivers",
"water falls"
] | A | freezing causes a solid to form |
OpenBookQA | OpenBookQA-3004 | the-moon, solar-flare, dust
Title: Any new info about solar flares hitting the Moon added by the LADEE mission? This article from 2011 mentions simulations about the sputtering effect caused by a solar flare hitting the Moon:
"We found that when this massive cloud of plasma strikes the moon, it
acts like a sandblaster and easily removes volatile material from the
surface," said William Farrell, DREAM team lead at NASA Goddard. "The
model predicts 100 to 200 tons of lunar material – the equivalent of
10 dump truck loads – could be stripped off the lunar surface during
the typical 2-day passage of a CME."
The researchers said they were waiting for LADEE to confirm these simulations and add new data, but I didn't find any conclusions on this subject on the mission website. I was interested if this event can create a significant static electricity difference between the 2 sides of the Moon, causing some sort of lightnings on the edges or even a mini-version of a dust storm. You'd probably be most interested in the results of the Lunar Dust EXperiment (LDEX). A 2015 paper states
LDEX data show no evidence for an electrostaticallylofted
dust component at densities greater than a few
per m3
I am assuming the solar flare stuff didn't pan out, otherwise it would be mentioned in the various LDEX summary papers. In addition, the NASA DREAM group site doesn't seem to have anything relevant LADEE results, and they're the ones that brought the subject up in the first place.
The following is multiple choice question (with options) to answer.
The moon has many craters on the surface due to space rocks | [
"candy canes",
"bumping into it",
"rain drops",
"cats"
] | B | the moon 's surface contains many craters |
OpenBookQA | OpenBookQA-3005 | pathology
Title: Why are some bodily fluids more of an infection risk than others? Whilst on a recent refresher course it was highlighted that when considering risk of exposure to infection from bodily fluids we should be aware of two distinct risk levels:
High Risk:
Blood
Semen
Vaginal Secretions
Diarrhea
Low Risk:
Saliva
Vomit
Urine
CSF (Cerebrospinal fluid)
Why is it that some bodily fluids are a greater infection risk than others? Is it related to the fluids themselves or the species of pathogen that are located within them? This is just about where the pathogens can be found that are dangerous to people.
Vomit is highly acidic and less accommodating to microbe growth. Similarly saliva has many immune components in it as well as digestive enzymes that keep most microorganisms down.
Urine and CSF are actually quite sterile as they come from environments that are highly filtered - the kidney is an osmotic processor that essentially is a molecular filter and does not allow cells to pass, the spine is highly insulated from the blood and other direct exposure to microorganisms.
Compare that with the 'dangerous' list and you have organs that are open to human pathogens. Venerial disease like HPV is so common that what - about 1 in 5 people under a certain age carry it. That is a pretty high expectation of a biohazard. most infections and viruses are blood bourne - influenza, cold, as well as any bacterial infections.
Feces is always a dangerous thing to handle as the digestive tract is rich in nutrients and essentially directly open to external bacteria and fungi. (and its not acidified like the stomach). Also parasites like tape worms and other multicelled animals! yum!
Diarrhea is often caused by an infection of some sort, so its just more likely a hazard, but feces is always a place where you might find a pathogen.
This is not to say that the 'safe' list is totally safe. Its just less likely to bear disease causing agents.
The following is multiple choice question (with options) to answer.
Which of the following could harbor unsafe bacteria? | [
"hand sanitizer",
"unwashed greens",
"properly cooked beef",
"washed carrots"
] | B | bacteria can cause people to become ill |
OpenBookQA | OpenBookQA-3006 | • I am also stuck at this point. If the first rose is $Red$ then the Bride enters the Church and in that case the probability is $\frac{10}{20}$. But now come the cases when the first rose is $White$: $WRR$, $WWRRR$, $WRWRR$ and so on. No matter what, if the first rose is $White$, the last two roses must be $Red$. And the total number of roses required ($\leqslant 20$) to enter the church is $Odd$, where the number of $Red$ roses will never exceed that of the $White$ roses but once when the Bride finally enters the church. Leaves me in doldrums, though. – JackT Oct 18 '17 at 7:42
• @Maths_student Actually, if you have got $x_1$ Red Roses and $y_1$ White roses, then you must get $y_1-x_1+1$ more red roses to enter the church. Or, rather, $x_2-y_2$ should be $y_1-x_1+1$. – MalayTheDynamo Oct 18 '17 at 7:49
• Your edit is incorrect. If she takes a red rose on the first try, she enters, so the probability has to be at least $1/2$ as you said. She can also enter the church if she initially takes a white rose, then takes two red roses in a row. Clearly, the probability is much greater than $1/20$. – N. F. Taussig Oct 18 '17 at 9:34
The following is multiple choice question (with options) to answer.
If a hundred bees swarm a pink rose and a dozen bees swarm a yellow lily, the lily will | [
"have more offspring than the rose",
"be lifted from the ground",
"have fewer offspring than the rose",
"be consumed and wilt"
] | C | as the number of pollinators attracted to a flower increases , the ability of that flower to reproduce will increase |
OpenBookQA | OpenBookQA-3007 | electromagnetism, electric-current
In cases of a conductor where $σ=∞$ and hence $f=0$, is it that current is moving so slowly that $J$ can be approximated to be zero is it that all current in the conductor stops?
This seems to be a wrong assumption. The word hence shows me that you think it is obvious that electric field $f$ would be close to zero at a large $\sigma$. This makes no sense, and I think you are mixing up conductivity $\sigma$ with resistivity $\rho$.
If on the other hand you wish to keep a certain current density $J$ constant, then yes, for a very large $\sigma$ a much smaller $f$ is neede to cause the same current. This makes sense, since much better conductivity $\sigma$ logically means that much less force $f$ is required to move a charge and cause current flow $J$.
How is this situation any different from when $σ=0$?
$σ=0$ means bad conductivity (and high resistivity against any current). For $σ=0$ no current will flow at all. This is an insulator, like plastic, that will not move charges.
The following is multiple choice question (with options) to answer.
Electrical flow can be slowed down if there is an insulator | [
"protected",
"avoided",
"active",
"demoted"
] | C | an electrical insulator slows the transfer of electricity |
OpenBookQA | OpenBookQA-3008 | 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 to the environment can be | [
"a toad finding a home",
"turtles eating small pellets",
"birds swimming in a pond",
"flowers poking through snow"
] | D | seasons cause change to the environment |
OpenBookQA | OpenBookQA-3009 | tissue
Title: Tissues in plants and animals
What is the equivalent connective tissue in plants?
Connective tissue in animals are mostly made up of collagen.
What about in plants?
Connective tissue in animals are mostly made up of collagen
Tissue is not like a simple chemical mixture ; rather tissue means a group or assemblage of cells, obeying certain defining-characteristics.
Animal connective tissues contain collagen mostly in the extracellular matrix. There are also other cell-constituents like phospholipid(membranes), DNA, RNA, etc. Blood is a liquid connective tissue which do not contain collagen in its matrix (plasma)
What is the equivalent connective tissue in plants?
Connective tissue is defined as all the tissues originated from the mesoderm layer of the animal embryo.
Now plants have a different mode of development than animals (plausibly due to evolution in separate route). So no part of a plant-body is homologous with a part of animal-body. It is impossible to bring a compare.
However; plants too; have their extracellular matrix; which is more popular as plant's cell wall (that contain cellulose, hemicellulose, etc.) as well there are intercellular spaces.
Still, if you forcefully want to bring a comparison; then the ground-tissue system of plant maybe called as a rough analogy with connective tissues in animals ( Similarly epidermal tissue of plant maybe a rough analogy with epithelial tissue of animals)
The following is multiple choice question (with options) to answer.
Special plant tissues transport what throughout the plant? | [
"dirt",
"manganese",
"animals",
"rage"
] | B | special tissues in plants transport minerals throughout the plant |
OpenBookQA | OpenBookQA-3010 | classical-mechanics, energy-conservation
Notice that we have basically three stages. In the beginning, we accelerate rather rapidly up to nearly optimal speed. Then in the middle portion we travel at nearly optimal speed in order to cover ground, and then at some point, we coast to reduce our speed, and finally brake to end up with zero velocity at the end.
We can also see our fuel use as a function of distance and compute the total fuel use and fuel economy for this trip:
The following is multiple choice question (with options) to answer.
As the use of alt fuels increases, the use of what will decrease? | [
"reusable fuels used for heating",
"fuels of the non reuse type power",
"fish swimming upstream in river",
"more hydro-electric power altogether"
] | B | something reusable can be used more than once |
OpenBookQA | OpenBookQA-3011 | human-anatomy
Taken from here such people would be able to dislocate then get their hands in front and relocate.
The body can be trained to be quite flexible through training like gymnastics etc...
The following is multiple choice question (with options) to answer.
Nerves all have | [
"microscopic parts",
"short arms",
"viable organs",
"liver transplants"
] | A | nerves are made of nerve cells |
OpenBookQA | OpenBookQA-3012 | 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.
What requires nutrients to grow and heal, and use a bill type instrument to process them? | [
"metals",
"dirt",
"birds",
"bear"
] | C | birds with beaks of different shapes eat different foods |
OpenBookQA | OpenBookQA-3013 | photons, everyday-life, renewable-energy, solar-cells, dissipation
Title: Why not use our own light production to produce new energy instead of wasting it? Why don't we use our own light production at night (I mean home, buildings, streets,..., lighting) to charge photovoltaic panels instead of wasting it? Solar panels work with sunlight. The energy per square meter of light from the sun , depending on the geographic area etc is of order of
8 hour summer day, 40 degree latitude 600 Watts per sq. meter
In one hour a photovoltaic cell of one square meter will provide energy of 600 watthours
Take a light bulb of 100 Watthour . To gather all that irradiance one would need to cover all the walls of the room with photovoltaics, which typically are 30% efficient. So one would gather 30 watthour of that "wasted energy" for an enormous cost in photovoltaics. ( disregarding that photovoltaics should be specially developed for low intensity conditions and as pointed out in the comments that a lot of that energy is in the infrared spectrum ).
In analogy will be the economics for other situations, Take a stadium with its large light sources, the power falls as $1/r^2$, where r is the distance between the light source and the panels.
The following is multiple choice question (with options) to answer.
Grow lamps provide artificial sun to | [
"bricks",
"dogs",
"succulents",
"fish"
] | C | a plant light is used for help plants by mimicking sunlight |
OpenBookQA | OpenBookQA-3014 | geophysics, sedimentology, glaciology, topography, isostasy
Are there any other reasons? What are the relative proportions in magnitude of these factors? Forming of coastline
During the last ice age, the North Sea was dry. When the ice melted sea levels slowly started to rise again and due to tides and currents
a barrier of dunes was formed along what approximately is today's coast line. This created an area of land that fell dry during ebb-tide and flooded during high tide (this can still be seen in the 'Waddenzee' in the North of the Netherlands where you can walk to some of the islands during low tide). The big rivers that flow through the Netherlands brought in more sand, slowly keeping larger parts of the land dry.
Isostatic rebound
During the ice age, the surface of Scandinavia was pushed down. After the ice melted it started to rise again and pushed the Western and Northern part of Netherlands down. Strangely enough the Southern and Eastern parts of the Netherlands are rising, so it seems the Netherlands is tilting.
I'm not sure how large the isostatic effect has been, but we know that the North of the Netherlands is still going down with about 2cm per century (source in Dutch).
Human influence
I know you've asked for non-anthropogenic causes, but I'm going to include this anyway because it seems human influence has had a much bigger effect on elevation than the isostatic rebound.
In the 11th century the Dutch started to actively shape the land by building dikes and later also by using wind mills to pump out water. The Flevopolder is an example of a large part of land that has been created by the Dutch in the 1950s and 60s. When groundwater levels became lower the moors settled and started oxidizing. Researchers think that the settling and oxidation of moors today is responsible for up to 15mm decline per year (source in Dutch).
Additionally in the 16th and 17th century a lot of peat was removed from the moors and used as fuel. Peat removal created new lakes, but some of those lakes were pumped dry later and were used as farmland. Also, the weight of dikes and houses on moors still cause subsidence today in areas in the West.
In the Northeastern part of the Netherlands gas extraction has also caused local elevation drops of up to 30cm (source in Dutch) in the last 40 years.
Other sources (all in Dutch):
The following is multiple choice question (with options) to answer.
Northern countries have extensive erosion due to | [
"glacial liquification",
"cola mining",
"more frequent tornadoes",
"meteors"
] | A | glaciers melting has a negative impact on the glaicial environment |
OpenBookQA | OpenBookQA-3015 | One important takeaway here is that we're not thinking of "implies" in terms of causality or possibility. If you want to talk about such things, we have to go beyond propositional logic - modal logic is a good place to set up shop.
Any if-then statement beginning with "If" and then something that has a value of False (not P in this case) is what's called "vacuously true". In some sense, it doesn't matter whether or not the implication would have held if that false statement after the if were true, because it isn't.
Your reasoning is fine ... but it's just that within the context of logic, any kind of 'if .. then ..' statement is analyzed using the mathematically defined material conditional ... and that can lead to some unexpected results since thate material conditional does not always quite match the English conditional.
So, you didn't "screw up" ... in fact, you were right to question this very result, but there are also excellent reasons for analyzing 'if .. then..' using the material conditional, so you better get used to the material conditional in the context of logic.
If you want to know more about this very issue, I suggest you look up "paradoxes of material implication"
You need to go back to the definition of the implication :
$$\begin{matrix} P & Q & P \Rightarrow Q \\ true & true & true\\ true & false & false\\ false & true & true\\ false & false & true \\ \end{matrix}$$
Now let's adapt it to the proposition ' If (not P) then (not Q)', i.e. $not(P) \Rightarrow not(Q)$:
$$\begin{matrix} P & Q & not(P) & not(Q) & not(P) \Rightarrow not(Q) \\ true & true & false & false & true\\ true & false & false & true & true\\ false & true & true & false & false\\ false & false & true & true & true\\ \end{matrix}$$
The following is multiple choice question (with options) to answer.
What is likely true? | [
"cacti will be in snowy regions",
"cacti will be in rocky regions",
"cacti will be in sandy regions",
"cacti will be in watery regions"
] | C | a desert environment is dry |
OpenBookQA | OpenBookQA-3016 | 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 shrew requires this for survival. | [
"radiation",
"air",
"silicone",
"clothes"
] | B | an animal requires air for survival |
OpenBookQA | OpenBookQA-3017 | c#, wpf, mvvm
no longer violates MVVM and works well with DI.
Also, prism uses plugin-based architecture. You define regions in your MainWindow, and then implement independent modules, which are plugged into those regions at runtime. I don't see you doing any of that. I think you should spend some time reading prism documentation. If you do it right - prism will wire your views and viewmodels automatically based on convention and you won't have those problems. Personally, I hate convention-based design just as much as I hate service locators (including ViewModelLocator). But if you chose to use prism, you should play by its rules. Fighting it or doing it wrong will only make things worse.
The following is multiple choice question (with options) to answer.
Which can be used to create a prism? | [
"dried dung",
"pine martens",
"teak",
"jello"
] | D | a prism refracts light |
OpenBookQA | OpenBookQA-3018 | everyday-life, diffusion, navier-stokes, convection
Diffusion in still air over distances of 400m usually takes a few hours rather than seconds, so I think that advection (the bulk movement of air) is likely to have been the dominant factor in the reported cases (as you suggested). Windspeeds at 10m above ground are typically 5m/s, decreasing downwards, so a transport time on the order of 100s is reasonable. Strong winds would reduce this time, but the descriptions "within seconds" and "almost instantly" seem somewhat exaggerated.
The following is multiple choice question (with options) to answer.
Which would likely spread the fastest? | [
"exhaust from a car",
"windshield fluid from a car",
"metal from a car",
"water from a car"
] | A | when a gas in an open container evaporates, that gas spreads out into the air |
OpenBookQA | OpenBookQA-3019 | Suppose A and B are statements of interest. Suppose we want to say in a short sentence that “whenever A is true, B is true, and that when A is false, we do not claim anything about the truth of B”. We use the word “implies” and state for short that “A is true implies B is true”, and mean the truth relations in the truth table you wrote. For this truth table, it wouldn't be meaningful for a good definition of "implies" to have A is false, B is true, "implies" is true. This would mean we are stating that B is always true, which is a valid claim to make, but not very helpful for a suitable definition of "implies".
Keep in mind we could state a different claim, namely, that “whenever A is true, B is true, and whenever A is false, B is false”. Here we are interested in claiming something about the truth of B when A is false. In this case we use the relation “iff” for short. We use this relation make the brief statement: “A is true if and only if B is true” and mean a different set of truth relations. In particular, A is false, B is false, the relation “iff” is true. Further, A is false, B is true, "iff" is false.
Now when you substitute “real” phrases for A and for B, you have to understand clearly what you are stating. Let’s say A is “Sticking a fork in an electrical outlet” and B is “you will get hurt”. Stating “A implies B” is the same as claiming that “if you stick a fork in an electrical outlet, you will get hurt”. This claim may not in reality be true, but that point is irrelevant to the statement from a logical point of view. The key point is that you are claiming nothing about getting hurt if you don’t stick a fork in the outlet. So in short, at this point it’s a matter of defining suitable definitions for useful relations, not about physical reality. Later of course we can do experiments, observe Nature, etc. to test if our claims hold up.
The following is multiple choice question (with options) to answer.
Which is true? | [
"the equator has winter and summer at the same time",
"humans on the equator celebrate Christmas in May",
"the equator is always cold",
"humans on the equator can go either north or south to change season"
] | D | winter in the Northern Hemisphere is during the summer in the Southern Hemisphere |
OpenBookQA | OpenBookQA-3020 | diffusion
Title: Permeability of containers to poop smells I do a lot of hiking trips that involve driving for an hour or two to the trailhead in the predawn hours. I'm a morning pooper, so I need to poop during the drive. Before COVID, I would usually plan a stop along the way at a Starbucks, get coffee, and use their bathroom. Then if necessary I'd also use a bathroom at the trailhead. Right now, during COVID, these bathrooms are all closed, so my new normal is that I pull over somewhere in the countryside, poop, collect my poop using one of my dog's poop bags, and bring it with me to a town or trailhead where I can dispose of it.
Sometimes this was stinking up my car, even though the bag was tied shut, so I tried putting the poop bag inside a large plastic (PETE) can that some nuts came in, and sealing it with the screw-on lid. Even then, there have been times when the smell seeped out within 30 minutes. Sometimes the smell has been like sour milk, sometimes like sulfur or eggs.
If I want to make this work better, what should I be focusing on? Is ~0.5 mm of PETE likely to be permeable to the smelly volatile compounds involved? Or is the issue more likely to be that there's a poor seal at the screw threads? Would I be better off trying something like the glass jars with clamping lids that people use for their coffee? A tupperware-style container with an o-ring seal? What kind of material should I be looking for in a gasket or o-ring?
(The other option I've tried successfully is to clamp the poop bag under a windshield wiper, so it's outside. But I'm worried this would, uh, catastrophically fail if I then drove at freeway speeds.) The problem likely is not (so much) the plastic material of your container, either solid, or bag.*) Assuming there is no contamination on the outer side of the container, most likely the smells are noticed because of closing the container by either knot or lid is not tight enough.
The following is multiple choice question (with options) to answer.
in order for a person's burger to make it successfully into the toilet, which of these must be functional? | [
"the respiratory system",
"the digestive system",
"the circulatory system",
"the destructive system"
] | B | the digestive system digests food for the body |
OpenBookQA | OpenBookQA-3021 | atmosphere, climate-change, climate
Title: Why is the temperature *still* rising? 2015 is the hottest year on record, and the average temperature continues to rise.
I don't understand why this continues, as (over the past twenty years) so much work was put into reducing Global Warming over the past 40 years, yet not only does the temperature not fall, it continues to rise more than it did between 1870-1960.
I don't understand something. The amount of industry went through the roof (literally) between 1870 to 1960, and no one cared about the environment
Now that we do care about it, and (at least somewhat) legislate cleaner cars, factories, etc, I would expect the temperature to even out, yet it doesn't
Why not? "So much work"? Actually, compared to the global rate of greenhouse gas emissions, it's a case of "so little work"! From a scientific perspective the 'economists' solution' of carbon trading was always unlikely to achieve the required carbon cuts, as has been verified by their ineffectiveness over the last decade or so. As farrenthorpe points out, the rate of increase of CO2 is largely population-driven, and hence there is still an inexorable rise in mean atmospheric CO2. The acid test of human efforts to limit global warming is whether the Hawaiian CO2 monitoring graph is flattening off:
It clearly isn't going to flatten anytime soon. In fact, if anything, it is getting steeper. So all the hot air from 'Paris', and previous talkfests, is evidently too little, too late. Realistically, limiting the average temperature rise to less than 2 °C, is now effectively unattainable. We have yet to see what 'all this work' can achieve. So far, almost nothing.
The following is multiple choice question (with options) to answer.
If the world has a universal temp increase, then | [
"ice chunks get small",
"glaciers will grow larger",
"water will stop existing",
"things will be fun"
] | A | if the atmospheric temperature rises then the glaciers will melt |
OpenBookQA | OpenBookQA-3022 | species-identification
Title: Trying to identify the tree in this picture. Shot from the Nepenthe restaurant, Big Sur, California I'm trying to identify the tree in this picture. This was shot from the Nepenthe restaurant, Big Sur, California.
Any help is appreciated!
Thanks,
Robert It's difficult to make out the leaves in the photo, but the tree in the foreground appears to be a coast live oak (Quercus agrifolia). The tree has hairy lichen growing on its branches.
The following is multiple choice question (with options) to answer.
A large oak can create | [
"water with salt",
"other oak creatures",
"watermelons",
"kites"
] | B | a tree can be replaced by planting a new tree |
OpenBookQA | OpenBookQA-3023 | 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.
Which eats other creatures? | [
"rainbows",
"cows",
"lynx",
"rabbits"
] | C | if an animal eats another animal then that animal is a carnivore or omnivore or predator |
OpenBookQA | OpenBookQA-3024 | newtonian-gravity, orbital-motion, space
To sum up, the co-orbital moons are likely close to ideal for body-jumping. There are definitely other places like between big chunks in Saturn's rings where this could be done. But beyond that you need implausible precision and durability.
The following is multiple choice question (with options) to answer.
Where would jumping be the hardest? | [
"Mars",
"Jupiterr",
"the Earth",
"the moon"
] | B | as mass of a celestial body increases , the force of gravity on that planet will increase |
OpenBookQA | OpenBookQA-3025 | c++, object-oriented, game, snake-game, curses
void game::play()
{
bool b;
genFood();
setSnake();
mvprintw(8, COLS/2-20, "??????????READY??????????????");
refresh();
sleep(1);
int ch= 0;
timeout(50); //adjust speed of the game
while((ch=getch())!= 'q')
{
switch(ch)
{
case KEY_UP: direction= 1;
break;
case KEY_DOWN: direction= 3;
break;
case KEY_RIGHT: direction= 2;
break;
case KEY_LEFT: direction= 4;
break;
}
clear();
map();
mvprintw(food_y, food_x,"F");
moveSnake(direction);
refresh();
b= check();
if(!b)
{
clear();
mvprintw(max_y/2-2, max_x/2-8, "GAME OVER");
mvprintw(max_y/2, max_x/2-10, "YOUR SCORE %d",score);
refresh();
sleep(2);
break;
}
}
}
bool game:: check()
{
bool b= false;
snake s= l.get(1);
int head_x= s.getX();
int head_y= s.getY();
if(head_x== max_x-1 || head_y== 1 || head_x== 1 || head_y== max_y-1)
return false;
else
{
int len= l.listLength();
for(int i= 4; i< len; i++)
{
s= l.get(i);
if(head_x== s.getX() && head_y== s.getY())
{
b= true;
break;
}
}
if(b)
return false;
else
return true;
}
}
The following is multiple choice question (with options) to answer.
Toy submarines bob up and down when put in a bowl of | [
"rice",
"vinegar",
"ice",
"sand"
] | B | baking soda can react chemically with vinegar |
OpenBookQA | OpenBookQA-3026 | rocks, remote-sensing, archaeology, ground-truth
Together, #1, #2, and #3 tell us that it's probably early summer just after the river ice has broken up.
The tooth-like features in the left image are simply erosional remnants sticking out of the riverbank. They could be bedrock (not likely), ice wedges, unmelted permafrost, or simply dirt. They are on the outside of a meander, so the river is actively cutting into them, and so the river-facing faces are quite sheer and high compared to the slopes in between. The right side might be white because the conditions there had left the snow unmelted when the image was taken. And of course their shadows are longer because the river channel is at the bottom of the bluff.
If you use Google Maps or Earth to go downriver a bit (up and to the left), you will see similar features sticking out of the riverbank, but because they're at a different angle from the features in your image, the fact that they're natural is more readily apparent.
Although the terrain is much less regular on the right side of the image, again the long shadows tell the tale. There are some round lumps that may be pingoes. The shadow that looks like a man is just a coincidental jumble of shadows from the broken terrain. If you look closely at the lump that is supposed to be the "man" (which would technically be an inunnguaq) does not have any protrusions that correspond to the "arms". The "arms" are the shadow of a little cliff or shelf past the lump, which is overlapped by the lump's larger shadow.
It's similar in effect to the infamous misinterpretation of a Viking orbiter image of a natural feature on Mars as a "Face on Mars".
This is a good example of the complications of image interpretation, specifically, understanding the conditions under which the image was taken. It's also a good time to emphasize the importance of doing ground truth when interpreting images. So when you go there, let us know what you find.
The following is multiple choice question (with options) to answer.
The below surface pebbles of the columbia river are of non rough edges because of? | [
"rough rocks",
"river movement",
"smoothness",
"fish movement"
] | B | rock is made of minerals |
OpenBookQA | OpenBookQA-3027 | 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 can enjoy a lovely snack on | [
"iris dust",
"fresh whale",
"hard leather",
"old shoes"
] | A | bees eat pollen |
OpenBookQA | OpenBookQA-3028 | species-identification, entomology
Title: I need help identifying a bug Basically this tiny bug plopped on top of my laptop keyboard. And as much as I disdained bugs, this one didn't look like anything I've ever seen. It had something that resembled bits of a dandelion on its back, and its body seemed like half a moth/ whatever insect. After closer inspection, I thought it was just a dying moth, the thing on its back being clipped wings and its body cut in half... but when i tried to shove it off the keyboard with my pen, it jumped about a hundred times its width onto my wall - instantly. Tried to get a second picture but it jumped again/disappeared... no idea where it went, or what it was... Here's the picture I took, and a quick sketch of what it looked like. This looks like an immature passionvine hopper (Scolypopa australis). They are informally known as fluffy bums.
Source: http://ketenewplymouth.peoplesnetworknz.info/friends_of_te_henui/images/show/1486-nymphs-fluffy-bums-scolypopa-australis
This is am image of the adult stage from the Encyclopedia of Life site:
More information can be found at the Encyclopedia of Life link above. It appears that their distribution may be only in Australia and New Zealand and I'm not sure where this photo was taken so take this information into consideration.
The following is multiple choice question (with options) to answer.
Where might you find a bug that has an incomplete metamorphosis | [
"a noggin",
"in space",
"on the moon",
"on Jupiter"
] | A | incomplete metamorphosis is when an insect reaches the adult stage without being a pupa |
OpenBookQA | OpenBookQA-3029 | toxicity
Cigarette smoke is a complex and dynamic aerosol consisting of at least 5,600 chemicals and toxicants found across two phases, the particulate (tar) and vapour phase.
(I would like to add the gas phase...) so when the product of the combustion of the tobacco are in this physical state you have to look at a different method of administration in this case vapour inhalation, Dust and Mist Inhalation and gas inhalation these are the most potentially dangerous method of administration. It seems that after about 40 minutes the liquid and solid part of the aerosol deposit (of course this depends on the condition, T, wind etc. etc.) so is probable that after this period of time the toxicity of tobacco combustion products decrease considerably. However this is not true for all the combustion products. For example: carbon monoxide is recognize tobacco combustion product and it is a gas so it wont deposit after this time and it will be "removed by reactions with OH radicals (85%), by soils (10%), and by diffusion into the stratosphere" very slowly.
Benzene is a good example of how the toxicity depends on the method of administration. LC50 inhalation value of benzene is 10000 ppm TFLo Dermal is 0.92 mL/kg so it is a big difference if you wait that the areosol deposit or if you inhale it.
If you are interested in rate of decomposition of benzene it seems that biodegradation of benzene can reach 0.95% at day according to Chiang.
Regarding 1-3 butadiene according to William A. McClenny and Donald Whitaker:
i.e., a 10-6 lifetime risk level for cancer due to inhalation exposure
of 0.03 $g/m^{3}$ (12.4 pptv at 20 °C and 1 atm pressure).1 This compound
is very reactive in the ambient atmosphere with a short
atmosphericlifetime, estimated to be 2–3 hr.
The half-life of acrolein is 14.4 hr.
You can also find a very complete EPA report EPA/600/P-98/001F
October 2002.
However determine the half-life of all the compounds is a very complex task because is related to how the ecosystem respond to these compounds so to the actual capability to decompose them through different mechanism is strictly related with thousands of factors.
The following is multiple choice question (with options) to answer.
if a driver drove by a corn field and tossed out his lit cigarette, what could happen? | [
"the corn will grow stouter",
"the corn would experience conflagration",
"the corn would grow bigger than normal",
"the corn will be more tasty"
] | B | fire destroys plants in an environment |
OpenBookQA | OpenBookQA-3030 | oceanography, rivers, satellite-oddities
Title: What are these river/canyon-like carvings in the ocean? Browsing around Google Maps, I came across this off the south-west coast of Ireland
It looks very consistent with the shape rivers and their tributaries might make, but it has me puzzled since it's all underwater!
The main, most "river-like" one is in the middle-left of the picture but there are more (which look more like fjords) at the bottom.
What caused this feature? The carvings are submarine canyons, a part of the continental slope leading from the continental shelf to the continental rise and ultimately the Abyssal plains. They are a product of :
erosion through currents and
slumping of the continental shelf
Like other erosive or slumping effects, they can be self-reinforcing, leading to canyon-like structures. The highlighted canyon here is the Gollum Channel system, seen here.
The following is multiple choice question (with options) to answer.
Which of the following would be seen outside of the ocean? | [
"a seahorse",
"an angler fish",
"a frog",
"a shark"
] | C | adult amphibians live on land |
OpenBookQA | OpenBookQA-3031 | electricity, electric-circuits, electric-current
I was wearing flip flops from the time I stripped off my neoprene wet suit at the car until the time I started getting shocked (my wife was wearing Birkenstocks).
I had been snorkeling for about an hour in the Pacific Ocean wearing a full body wet-suit, booties, and gloves (no hood).
I had been camping the night before and consumed quite a bit of Gatorade.
My wife had only been wearing a spring suit and gloves, no booties.
There was another receipt that had been left in the machine (maybe someone else had been shocked as well and decided it wasn't worth the risk of going after it?)
I can't think of anything else relevant. Any insights into what was going on here would be welcome. I tried calling the maintainers of the machine but couldn't get through (this was before I found out that I seemed to be the only one affected).
Thanks!
She tried touching the machine in various places, again nothing. I inadvertently touched her hand while she was touching the machine and then suddenly she felt it too.
From this it is evident you were a good conductor to the ground.
You later say :
We came back out 15 minutes later after drinking our hot chocolate and tried to reproduce the phenomenon with no luck.
So no charge was passing through you any longer?
15 minutes is too little a time to change your conductivity. It could be a combination of an intermittent fault in the circuit and your conductivity at that time. You should alert their maintenance to be on the safe side.
The following is multiple choice question (with options) to answer.
If I wanted to protect my feet from getting blisters I might | [
"pour alcohol on them",
"burn my legs in fire",
"rub them in acid",
"wear thick colorful socks"
] | D | as the thickness of an object increases , the resistance to damage of that object will increase |
OpenBookQA | OpenBookQA-3032 | intelligence
There might of course also be recessive genes on the X-chromosome causing males, who has only one X-chromosome, to be smarter but genes that are not causing disease might not be so interesting to investigate from a medical point of view.
According to wikipedia there are 499 x-linked genes and the total number of "vaguely defined traits" are 983.
I would say that yes, as a man you inherit more genes from your mother than from you father affecting your intelligence due to the fact that some genes on your x-chromosome affect your intelligence. Whatever the 499 x-linked genes do, you could say that traits affected by those genes to a greater extent are determined by your mothers genes than by your fathers, if you are a male.
Technically you would of course also have to take the genes on the y-chromosome, which are much fewer, into account.
The following is multiple choice question (with options) to answer.
If a child inherits a physical trait from his father he will likely receive | [
"tooth gap",
"favorite color",
"sense of fun",
"liking dogs"
] | A | inheriting is when a inherited characteristic is passed from parent to offspring by genetics |
OpenBookQA | OpenBookQA-3033 | python, programming-challenge
Title: Determine if Hill or Valley This is my accepted submission for LeetCode. The problem is
You are given a 0-indexed integer array nums. An index i is part of a hill in nums if the closest non-equal neighbors of i are smaller than nums[i]. Similarly, an index i is part of a valley in nums if the closest non-equal neighbors of i are larger than nums[i]. Adjacent indices i and j are part of the same hill or valley if nums[i] == nums[j].
Note that for an index to be part of a hill or valley, it must have a non-equal neighbor on both the left and right of the index.
Return the number of hills and valleys in nums.
The following is multiple choice question (with options) to answer.
If a river is flowing down the east side of a hill, then the hill | [
"drops at a slow rate",
"drops sharply right there",
"drops sharply on the west",
"is evenly sloped everywhere"
] | B | the slope of the land causes a river to flow in a particular direction |
OpenBookQA | OpenBookQA-3034 | earth-rotation, seasons, time
Title: Are the length of seasons the same globally? Is the length of time, say months, for each season the same all over the world or can it vary? As has been noted in a comment, it depends on how you define seasons (see https://earthscience.stackexchange.com/a/2603/111).
If seasons are defined in astronomical terms, then they have the same length everywhere on the planet. This is simply down to geometry.
However, the effects of astronomical seasons vary geographically in a number of ways. The magnitude of seasonal changes, for example changes in day/night lengths, is more pronounced in higher latitudes, so the effect of (for example) winter might be noticeable for a shorter time period in the tropics than the arctic, and hence some people might reasonably consider winter to be shorter there. There are other, less systematic variations that depend on local climate and weather. In weather terms, not everywhere in the world has the same 4-season cycle that temperate zones tend to experience - so when defining seasons in terms of observable effects one often has, for example, a wet season and a dry season rather than spring /summer /etc.
The following is multiple choice question (with options) to answer.
If a season switches from one to another in a place, the earth has | [
"exploded",
"stayed in place",
"moved more",
"frozen"
] | C | the Earth revolving around the Sun causes the seasons to change on its axis |
OpenBookQA | OpenBookQA-3035 | geochemistry, chemistry-in-fiction, minerals
Once you come up with a list of elements, you might want to ask the next questions in the Earth Science SE, not here.
The following is multiple choice question (with options) to answer.
Which would be excluded from a list of objects with metallurgical properties? | [
"iron",
"bone",
"gold",
"steel"
] | B | classifying means grouping materials by their properties |
OpenBookQA | OpenBookQA-3036 | resonance, vibrations, coupled-oscillators
Title: String Vibrations Interesting thing I noticed just now playing my ukulele.
For those who don't know how a ukulele works, it has four strings: a high G followed by a lower C, E, and A. Holding down frets causes the strings to play progressively higher-pitched notes. Now, it is possible for two or more strings to play the same note. I've noticed that when this happens, playing one string will cause the others of the same pitch to vibrate, even without actually playing them. However, it's only when they are exactly the same note. If it's not the same note, it doesn't vibrate (at least not perceptibly). Why? If it's caused by the vibration from the string spreading outward, why would it matter what pitch the strings are relative to each other?
Perhaps it's a property of the nylon in the strings? After noticing this, I checked on my steel-stringed acoustic guitar, which definitely does not (perceptibly) do this. The sound of a ukulele (or any similar instrument - guitar, violin, etc) does not come from the strings themselves, but from the whole body of the instrument vibrating and moving the air which is in contact with it.
The vibrations are transmitted from the strings to the body of the instrument mainly through the bridge.
If you stop two strings so that they produce the same pitched note, the vibration of the bridge will cause both strings to vibrate if you pluck one of them.
This will also happen on an acoustic guitar, but in an electric guitar the sound is not physically produced by the body of the instrument vibrating. Instead, by magnetic pickups sense the vibration of the steel strings and the electrical signals are then amplified and sent to a loudspeaker.
The same effect happens in instruments like the piano, but the steel strings are at a higher tension than in plucked instruments and there is no visible vibration of the strings (except perhaps for the lowest bass notes) in normal playing.
The following is multiple choice question (with options) to answer.
If an instrument is played, this may occur | [
"something is ignored",
"something is spit",
"something is flicked",
"something is killed"
] | C | An example of playing a musical instrument is hitting the keys of a piano |
OpenBookQA | OpenBookQA-3037 | physical-chemistry, everyday-chemistry, thermodynamics
As a comparison to this example, let's check out two liquids that do mix.
3. Water and ethanol
For the water, we have basically the same situation as before -- water molecules forming good bonds to each other. The ethanol, though, has an -OH group that can form bonds to the water in the same way that the water does (though not as well). This means that ethanol that mixes with water (and vice versa) will tend to stay mixed, and given that the liquids are being mixed around just by random motions, means that you'll get one mixing with the other just as a matter of statistics.
The following is multiple choice question (with options) to answer.
A good example of a mixture is | [
"dry wood and dry beans",
"ocean and lake water",
"rabbits and young hares",
"old bread and buns"
] | B | An example of a mixture is clay mixed together |
OpenBookQA | OpenBookQA-3038 | power, estimation, combustion
eg assume 6 kWh/kg for a sample of dry wood.
10% moisture would displace $\rm10\% \times 6000\,Wh = 600\,Wh$ from a 1kg mass.
$\rm600\,Wh = 600 \times 3600 = 2.16\,MJ$.
Energy to heat 100 g water 10$^\circ$C say to
$\rm100\,^\circ C \simeq 4.3\,J/^\circ C/g \times (100\,^\circ C-10\,^\circ C) \times 100\,g \simeq 40\,kJ$.
Energy to vaporise 100g of water from
$100\,^\circ\,\rm C$ to steam = $\rm2260\,J/g\times100\,g = 226\,kJ$
Total energy loss due to vapourising 10% water = $266\,\rm kJ$ = 11%
Loss of energy from water replacing wood = $2160\,\rm kJ$ = 89%.
Total loss to water = $2.426\,\rm MJ$.
Energy loss % in 1 kg wood due to 10% moisture = $\rm2.426\.MJ/21.6\,MJ$ = 11.2%
Not taken into account is the "watergas" process whereby passing water vapour over hot carbon results in breakdown of the water into Hydrogen and Oxygen and re-re action to form CO and CO$_2$. The net energy effects of this process vary immensely with circumstance and are ignored here.
Based on Warm Homes technical report.
The following is multiple choice question (with options) to answer.
Wood is generally dried out for | [
"dogs",
"turtles",
"beds",
"cats"
] | C | dry wood easily burns |
OpenBookQA | OpenBookQA-3039 | thermodynamics, energy, temperature, estimation
Title: What would happen if a 10-kg cube of iron, at a temperature close to 0 kelvin, suddenly appeared in your living room? What would be the effect of placing an object that cold in an environment that warm? Would the room just get a little colder? Would it kill everyone in the room like some kind of cold bomb? What would happen?
Don't think about how the cube got there, or the air which it would displace. Nothing overly dramatic, though it would be cool to look at. The cube would very quickly become covered by a layer of nitrogen/oxygen ice as the air which came into contact with it froze. Further away, you'd see condensation of water vapor into wispy clouds, which would swirl around the block due to the air currents generated by the sudden pressure drop.
Other than that, as long as you aren't in immediate thermal contact with the block, you wouldn't notice much other than that the room cools down. Here's a video I took of a vacuum can that was just removed from a dewar of liquid helium at 4 kelvin. It's maybe 5 kg of copper, not 10 kg of lead, but I'd say that's close enough to get the idea.
You can see one of my coworkers climbing down into a pit below it; he had to be careful not to bump his head on it, which would have really ruined his day, but there was no fatal cold bomb :)
The following is multiple choice question (with options) to answer.
if white cold items drop from the sky, what might these be? | [
"a gift from the heavens",
"a cloud is crying",
"it is an anomaly",
"it is ice precipitation"
] | D | snow falls during the winter in the arctic environment |
OpenBookQA | OpenBookQA-3040 | everyday-life, diffusion, navier-stokes, convection
Diffusion in still air over distances of 400m usually takes a few hours rather than seconds, so I think that advection (the bulk movement of air) is likely to have been the dominant factor in the reported cases (as you suggested). Windspeeds at 10m above ground are typically 5m/s, decreasing downwards, so a transport time on the order of 100s is reasonable. Strong winds would reduce this time, but the descriptions "within seconds" and "almost instantly" seem somewhat exaggerated.
The following is multiple choice question (with options) to answer.
What type of product can be made from the moving winds? | [
"snow",
"electricity",
"wood",
"bananas"
] | B | uneven heating of the Earth 's surface cause wind |
OpenBookQA | OpenBookQA-3041 | botany, species-identification
Title: Plant identification? Can anyone identify the plant below? It's in a backyard in Pennsylvania, and the photo was taken today. Those flowers don't come from the same plant as that big leaf in the front do they? Cant help you with the leaves, but the flower looks like a daylily. source: I know nothing about plants, but happen to have a mom who got a degree in horticulture :)
The following is multiple choice question (with options) to answer.
if a plant shows up in a new place, what might have happened? | [
"the plant is able to relocate itself",
"it spontaneously appeared there",
"it walked to the new place",
"its cased embryo have been dispersed"
] | D | seed dispersal is when the seeds of a plant are spread from the parent plant to another area |
OpenBookQA | OpenBookQA-3042 | human-biology
Title: Why do we sweat after drinking water and running? Why do we sweat after running?
Also we sweat sometime after drinking lots of water. Why it is so?
Can someone please enlighten me in this regard? Exercise, such as running, increases muscle activity. This increases the energy demand of these tissues, which increases the rate of cellular respiration. Respiration releases heat as a by-product, therefore the body is hotter during and after exercise.
Sweating is a homoeostatic mechanism to keep core body temperature constant. It is a response to lower the body temperature. When the body becomes too hot, sweat is released onto the surface of the skin. The water from the sweat then takes some of the excess heat energy from the body and uses it to evaporate. Because water has a relatively large specific heat capacity a lot of heat can be carried away by this method.
The following is multiple choice question (with options) to answer.
Sweating will make your body temperature go | [
"down",
"hits you",
"Sideways",
"Up"
] | A | when the body is hot , sweat is produced to cool the body |
OpenBookQA | OpenBookQA-3043 | palaeontology, herpetology
Title: How big can cold-blooded animals get? It seems impossible to have reptiles the size of dinosaurs, just because they are really big! Did they have different systems of maintaining body temperature or maybe they weren't the exact type of animals that we today call reptiles? Answer is quite simple as from @Alan Boyd link. They are cold blooded and thus, can go out for hunt in cold, they need to stay put till they get some prey.
So, it mainly depend on the temperature of the outside, I found this interesting paper on relation of body sizes and latitude.
Body sizes of poikilotherm vertebrates at different latitudes
Maximum sizes of 12,503 species of poikilotherm vertebrates were
analyzed for latitudinal trends, using published data from 75 faunal
studies. A general trend appears which may be summarized by the rule
"among fish and amphibian faunas the proportion of species with large
adult size tends to increase from the equator towards the poles". The
rule holds for freshwater fish, deepsea fish, anurans, urodeles, and
marine neritic fish arranged roughly in order of decreasing clarity of
the trend). In general the rule applies not only within these groups
of families but also within single families. In reptile groups, the
rule holds weakly among snakes and not at all among lizards or
non-marine turtles. Possible explanations include an association
between small size and greater specialization in the tropics; the
possibility in poikilo-therms of heat conservation or of some other
physiological process related to surface/volume ratio; selection for
larger size in regions subject to winter food shortages; and an
association between large adult size and high reproductive potential
in cold regions. Other suggestions can be advanced, but all are
conjectural and few are subject to test. Global size - latitude trends
should be looked for in other living groups.
Cite: Lindsey, C. C., 1966: Body sizes of poikilotherm vertebrates at
different latitudes. Evolution: 456-465
Now lets compare some of the largest cold blooded Animals:
Reptiles
Amphibians
Fishes (Pisces)
The following is multiple choice question (with options) to answer.
Which can best be described as hibernation for most amphibians? | [
"a brain dead frog in mud",
"a frog napping for an hour in mud",
"a frog burying itself in mud for months",
"a frog sleeping for the night in mud"
] | C | An example of hibernation is a frog burying itself in mud |
OpenBookQA | OpenBookQA-3044 | 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.
We might use our carbon dioxide waste to | [
"feed cats",
"feed sloths",
"feed roses",
"feed birds"
] | C | In the cellular respiration process carbon dioxide is a waste product |
OpenBookQA | OpenBookQA-3045 | zoology, mathematical-models, software, imaging
Title: What would it take to recognize a deer by its photo? I am trying to recognize a deer by its antlers or any other means.
Elaborating:
I was hoping to use their antlers to recognize them but I have heard that most deers shed their antlers every year so it would be difficult to recognize it from the last year's photo unless these antlers retain the same pattern every year.
If not the antlers, what other characteristics should I be looking for?
Is there any software that can help me in recognizing a deer? There is a lot of variation in how and when deer shed their antlers. In most arctic and temperate-zone species, antler growth and shedding is annual, and is controlled by the length of daylight. In tropical species, antlers may be shed at any time of year, and in some species such as the sambar, antlers last several years. Some equatorial deer never shed their antlers.
The horns change every year and, especially, increase the number of branches (and consequently, change their shape). You can't recognize them by antlers, but by other features, such as color of the hair or the lineaments. Like us, animals have individual morphological differences that are recognizable and listable.
Biologists specializing in studies of particular animal species not only take photos, but also make drawings and write descriptions of behavior, to identify individuals within herds.
An optical examination, however, of the subject through drawings and photos (and if possible, direct observation), is more useful than a PC program. This involves identifying particular similarities and equalities that are not "identical". This is possible to do visually on a large (but limited) number of specimens. The human eye is the best computer.
The following is multiple choice question (with options) to answer.
If a deer lives in a place with trunks, the area is likely to be a color matching a | [
"grasshopper",
"sky",
"clownfish",
"banana"
] | A | a forest environment is often green in color |
OpenBookQA | OpenBookQA-3046 | zoology, ichthyology, marine-biology
Switek goes on to to talk about exceptions in some marine mammals:
At this point some of you might raise the point that living pinnipeds like seals and sea lions move in a side-to-side motion underwater. That may be true on a superficial level, but pinnipeds primarily use their modified limbs (hindlimbs in seals and forelimbs in sea lions) to move through the water; they aren’t relying on propulsion from a large fluke or caudal fin providing most of the propulsion with the front fins/limbs providing lift and allowing for change in direction. This diversity of strategies in living marine mammals suggests differing situations encountered by differing ancestors with their own suites of characteristics, but in the case of whales it seems that their ancestors were best fitted to move by undulating their spinal column and using their limbs to provide some extra propulsion/direction.
The following is multiple choice question (with options) to answer.
A creature that is living will require this to have movement abilities: | [
"clouds",
"nutriment",
"glass",
"dirt"
] | B | an animal requires energy to move |
OpenBookQA | OpenBookQA-3047 | If the maximum number of fish caught is $$m$$, then the total number of fish caught is no more than $$m+(m-1)+...+(m-6)$$. So there is one fisherman that caught at least 18 fish. Repeat this process for the second and third highest number of fish caught and you should be good.
I should add that this is a common proof technique in combinatorics and graph theory. To show that something with a certain property exists, choose the "extremal" such something, and prove that property holds for the extremal object. For instance, to show in a graph where each vertex has degree at least $$d$$ there is a path of length at least $$d$$, and one proof starts by simply showing a maximal path has length at least $$d$$.
• If the most fish caught is $18$ that gives a tight result - there is a little work to check what happens if the largest number of fish caught is greater than $18$ Sep 30 '18 at 15:12
• @MarkBennet right, my thought was to iterate, i.e. After you choose the max $m$, replace $100$ with $100-m$ and $7$ fishers with $6$, this gives a bound on the second highest, etc. Thanks for pointing this out Sep 30 '18 at 15:15
• Not a problem - it actually gets a bit easier. This works and was my first way of doing it. Sep 30 '18 at 15:26
• Thank you for your solution. I accept Mark's solution because it is more accessible for kinds about 14 years.
– Aqua
Sep 30 '18 at 15:45
• @greedoid no prob! I would accept marks as well :) Sep 30 '18 at 15:45
I think I have a solution. First note that if $$r_4 \geq 15$$ then we have:
$$r_5 \geq 16$$
$$r_6 \geq 17$$
$$r_8 \geq 18$$
so $$r_5 + r_6 + r_7 \geq 16 + 17 +18 = 51$$ which is impossible.
Therefore $$r_4 < 15$$
The following is multiple choice question (with options) to answer.
tuna swim extremely fast to catch | [
"sharks",
"kelp",
"anchovies",
"starfish"
] | C | some predators move quickly to catch prey |
OpenBookQA | OpenBookQA-3048 | energy, photons, semiconductor-physics, solar-cells
Both approaches tailor the design of the solar cell to solar spectrum.
The latter is the most common approach and in essence you are using the spatial arrangement and the band gap property (which is different for each cell or "junction") of each material to split the spectrum across multiple cells.
The former approach is also currently being explored but require very optically efficient selective reflectors and are inherently more bulky and (probably) expensive.
Multijunction solar cells are the only real near term approach to very high efficiencies. The design of real cells is constrained because they can only be grown with materials that share the same lattice constant. There are other "mechanical stack" approaches which allows materials of different lattice constants to be stacked but this introduces many technological challenges.
In principle these approaches can achieve an 86% efficient device (with an infinite number of junctions or spectral slices). One reason why you don't see cells this efficient is because of the effect of diminishing returns. For example, you can jump from 30% to 55% efficient device when going from one junction to three. However, to get from 55% to 86% infinitely many more junctions are needed! Moreover, every time a new junction is added it contributes less to the overall efficiency enhancement. Furthermore, the technological difficult increases much faster as more and more junctions are added. At some point a limit will be reached beyond which there is little point in adding more layers.
Tailoring the spectrum to the solar cell
Your #4 is an example of the inverse, where the the spectrum is modified to better match the solar cell. These approaches are usually called photon up-conversion and down-conversion.
This can be achieved by utilising a three level system. Let's recap. Normal solar cell, and semiconductor in general, are two level systems meaning that there is a single dominant optical transition between the lower and upper level. However, with a three level system it's possible to use the additional optical transitions to change the energy of the absorbed photons.
In up-conversion one low energy photon causes a transition from energy level 1 (the lowest energy level) to level 2. Then a second low energy photon can cause a transition from level 2 to level 3 (the upper most level). Finally, the electron that has been promoted to level 3 can fall directly to level 1 in a single step. The two low energy photons have been converted to one high energy photon.
The following is multiple choice question (with options) to answer.
Which would most directly benefit from installing receptors for converting light into power? | [
"a family of humans in a city where it rains every day",
"a herd of crows",
"a research base near the equator",
"a group of squirrels"
] | C | a solar panel converts sunlight into electricity |
OpenBookQA | OpenBookQA-3049 | image-processing
Title: High Dimensional Spaces for Images Can anyone explain why pictures are not considered 2D, but rather high dimensional? Especially with regards to CV and AI. From one perspective, a picture is a 2D image, because it has height and width.
But from a machine learning perspective, we can think of a picture as a point in a high-dimensional space. In particular, suppose we have a greyscale picture that is $m\times n$ pixels, i.e., $m$ pixels wide and $n$ pixels high. Then there are a total of $mn$ pixels in the image. Each pixel has a greyscale intensity, which we can think of as a real number in the interval $[0,1]$. Therefore, we can think of the picture as being a collection of $mn$ real numbers. In other words, the picture can be treated as a $mn$-dimensional vector -- as an element of $\mathbb{R}^{mn}$. Thus, any particular picture can be thought of as an element of a high-dimensional space.
The latter perspective arises natural for some machine learning approaches to computer vision, e.g., where we feed the pixels of the image into the machine learning algorithm, where each pixel value is treated as a separate pixel.
(A color image can be thought of as an element of $\mathbb{R}^{3mn}$: for each pixel, we have three numbers, corresponding to the intensity in the red, green, and blue channels.)
The following is multiple choice question (with options) to answer.
High areas can be visually represented by | [
"basins",
"deep sea",
"valleys",
"mountains"
] | D | a valley is formed by a river flowing |
OpenBookQA | OpenBookQA-3050 | earth, universe, big-bang-theory, fundamental-astronomy, space
Title: Why do we we even exist? It came to my mind one day that why does this universe even exist and why do we even exist and like we are enclosed in the so called atmosphere and a floating rock in space called the Earth, so is there any possibility that the universe is also enclosed in something and if it is, then what is outside that enclosure? That's an interesting question, but as the comments say might be a better place to ask this question in the Philosophy SE site, but the question about the universe being englobed maybe by another much bigger 'space' is something we might never be able to prove right or wrong. This 'existential' question might refer to the holograph theory, the multiverse theory. The thing is, at the moment the only possible explanation of whats beyond the 'observable universe' boundary is nothing, neon, an infinite multi-dimensional plane of nothingness.
The following is multiple choice question (with options) to answer.
we only have diamonds because of the existence of | [
"raw bacon",
"machines",
"pressure",
"work"
] | C | extreme heat and pressure compact sediment into sedimentary rock |
OpenBookQA | OpenBookQA-3051 | everyday-chemistry, water, crystallography
Spin-off question:
I heard (not sure where) that each snowflake assumes a unique shape. How true is this?
Now, as I understand it, all processes proceed so as to maximize the "randomness" of its constituent particles. (Oversimplified version of the Second Law of Thermodynamics, yes, I know... just don't chew me out in the comments section...)
Yes. True.
This Law can easily be observed in, and verified by, natural processes.
Sure. Still with you.
Now the formation of snow is a natural process, agreed? The way my brain sees it, is that water droplets ought to freeze into random, and by virtue of its "randomness", highly unsymmetrical shapes. But this is not the case here!
The following is multiple choice question (with options) to answer.
Which of the following would occur in nature? | [
"an osprey catches a fish with claws",
"a fish catches a fish with its claws",
"a dog catches a fish with its claws",
"a worm catches a fish with its claws"
] | A | claws are used to catch prey by some predators |
OpenBookQA | OpenBookQA-3052 | astrophysics
Title: Is there any way to survive solarwinter like in Sunshine - movie? Is there any way to survive solarwinter like in Sunshine - movie?
Solar winter is where for some reason sun looses its capasity to produce radiation( heat etc.). It doesn't loose everything but some of its radiation energy( say 50 %) That causes earth to cool down causing next "ice age" Food could be grown using UV lights, powered by nuclear fission.
We could probably do it.
But it would be the spece equivalent of a human being on a life support machine - all our time and energy would be consumed just with survival, so while humans as a species might survive, our society, culture and science would probably slow down to a crawl, or disappear completely. Most other species would die off, so it would be a pretty dismal future.
The following is multiple choice question (with options) to answer.
Leaving your ice cream outside is never a good idea because it will absorb the solar energy from the sun which will do what to the temperature | [
"go up",
"explode",
"nothing",
"decrease"
] | A | if a substance absorbs solar energy then that substance will increase in temperature |
OpenBookQA | OpenBookQA-3053 | observational-astronomy, star
Title: What star is this? From this image, can you help me identify the star circled in yellow? This picture was taken mostly above my head, but facing slightly southeast, from the southwestern corner of Virginia. The circled star is Procyon (α CMi). The other stars, from the top, are Castor (α Gem), Pollux (β Gem), Al Kirkab (κ Gem), then the almost central triangle formed by Wasat (δ Gem), Mekbuda (ζ Gem), and Alkibash (λ Gem), then to its right Alhena (γ Gem) and Alzirr (ξ Gem). Just above and to the right of circled Procyon is Gomeisa (β CMi), and at bottom right the brightest star in the image is also the brightest star in the sky, viz. Sirius (α CMa), and to its right Murzim (β CMa).
Hope this helps!
I visited southwest Virginia many years ago. Nice neck of the woods. I stayed in Wise, but also went to Norton a few times.
The following is multiple choice question (with options) to answer.
The North Star is | [
"A person",
"A dog",
"A cat",
"many intergalactic beings"
] | D | the North Star does not move in the sky in the Northern Hemisphere each night |
OpenBookQA | OpenBookQA-3054 | mercury
As for a YouTube video saying the highest point is "Mt. Hermes," that sounds dubious to me with respect to anything official (for one, mountains on other bodies are "montes" after the Latin, if they have a formal name). A search shows no one else is using this name.
Regarding "sea level," it's what Wikipedia said: You use a reference ellipsoid, usually. The reference ellipsoid is made usually by fitting many different limb profiles to an ellipsoid, and/or via a laser altimeter. The best fit is the ellipsoid. Any deviations from that would be topography. Mercury has plenty-enough data to make a reference ellipsoid, indeed you linked to one in the comments above. Once these are published in the scientific literature, assuming they are generally accepted, the International Astronomical Union makes that a standard and publishes it in various reports. They don't often update their standards, though I think the last one was in 2015. So, it would not reflect the latest you found.
Practically all resolved solar system bodies have a reference ellipsoid that's used and published. How good it is, though, is another question. Asteroids, given their highly irregular shapes, for example, that were imaged by flyby missions would generally have a much more poorly constrained ellipsoid than, say, Earth's moon that has been observed through telescopes for over 400 years, orbited by numerous spacecraft, has retroreflectors on it, and has >8 billion laser altimeter points from the Lunar Reconnaissance Orbiter Laser Altimeter.
The following is multiple choice question (with options) to answer.
which of these formations are typically the highest point from sea level? | [
"the sandy river bank",
"a long river channel",
"a cooled lava top",
"a lush green valley"
] | C | a plateau is formed by a buildup of cooled lava |
OpenBookQA | OpenBookQA-3055 | newtonian-mechanics
I should add that the above is simply what I, as a physicist with a fairly long experience, suspect is what is going on. It is not something I have read about and I am sure there is somewhere a more thorough discussion. So I hope I am right; I think I have a good argument. As I have described it above, I have in mind mainly the last part of the process where the wood only moves a little relative to the metal. In the earlier part, when the wood moves through a larger distance, it is inertia that is the main consideration, just like in the party trick where you abruptly whisk away a table cloth and the dishes on the table stay where there are. The more abrupt the better.
Added remark
It occurred to me that there is another thing worth mentioning here, that makes this method preferable to resting the axe head on something, or supporting the handle on a work top and hitting the head. It is that by hitting the end of the handle, with the head just hanging, you are going to deliver the force more accurately at the join, because it travels along the handle in exactly the direction you want. If instead you strike the head then there is a danger it will be knocked slightly obliquely, introducing a random tilt with each blow, which is liable to deform the wood and thus loosen the fit.
The following is multiple choice question (with options) to answer.
A human can, merely by pushing on it, cause a visible alteration in the shape of a | [
"manly sculpture",
"inhumanly tall building",
"plastic dinner container",
"standard burning sun"
] | C | if a flexible container is pushed on then that container will change shape |
OpenBookQA | OpenBookQA-3056 | meteorology, tropical-cyclone, lightning, mesoscale-meteorology
The answer for Harvey is probably all of the above. Places like Houston were first in the further extents of the storm the early days and so were able to see the more typical fluctuations of strong rising updrafts and stronger sinking downdrafts more typical of normal thunderstorm convection and the outer rainbands in tropical cyclones. And then had a storm seeing important structural changes by the time it moved nearer Houston (as marked by the significant tornado outbreak)
And areas nearer the center of Harvey saw rapid intensification (indicating there was more instability nearer the storm center still), eyewall replacement, plus the usual frictional convergence at landfall all favoring a bit of an uptick in lightning. Harvey may well have not been too different from most landfalling hurricanes, but had the benefit of rapid intensification to help lightning production some... and it was dark so it could be seen more!
The following is multiple choice question (with options) to answer.
If a flood is occurring there was most likely | [
"light hail",
"clear skies",
"great droplets repeating",
"some leaves"
] | C | heavy rains cause flooding |
OpenBookQA | OpenBookQA-3057 | climate-change, hypothetical, solar-terrestrial-physics
Title: How much reduction of insolation (solar energy) would be required to stop global warming? Suppose a giant sheet of semi-reflective mylar (or some other kind of partial sun-screening material) was temporarily placed into space between the Earth and the Sun with the intent to lower the amount of solar energy reaching the surface of the planet.
How much solar radiation (and in what frequency ranges) would need to be filtered to cool the planet to the most-desirable global temperature? Also, would the entire planet need to be shaded or just a key area like the Equatorial region?
Obviously the plan would be to reduce the warming effect without dramatically darkening the day since so many plants require the visible spectrum of sunlight to live. It's not that hard to make an estimate.
CO2 traps about 2 watts per square meter. Direct sunlight at 1 Astronomical Unit is about 1,360 watts per square meter, but spread out over the earth, average night and day it's about 1/4th of that about 340 watts per square meter. (note, Casey's point is valid, it's probably better to use the number of watts that hits the Earth, so, my estimate is likely a bit low)
There may be more detailed and specific ways to look at it, but this is probably pretty close. If you shade enough sun to reduce 2 watts out of 340, or 1/170th, that should balance out climate change, at least at current levels.
From space, you can view the earth as a disk in terms of area needed for shade, so the 2D area of the earth is about 127 trillion square meters, and 1/170th of that, about 750 billion square meters, or 750,000 square KM, slightly larger than Texas and as you get closer to the sun, the area needed is reduced by the square of the relative distance.
Still, that's no easy task, to put up a shade the size of Texas into space and it's no easy task to keep it there as it would in effect by a huge solar sale and likely enormously heavy. It's far easier to simply build mirrors on earth than try to build something in space and I've seen that discussed as a possible solution to climate change. of-course, they'd need to be kept clean to be effective, it would require maintenance, but it's probably doable.
The following is multiple choice question (with options) to answer.
Which of the following would likely reduce pollution the most? | [
"using a truck instead of a car",
"using a bicycle instead of a motorcycle",
"using a car instead of the bus",
"using a motorcycle instead of a bike"
] | B | burning gasoline is a source of pollution |
OpenBookQA | OpenBookQA-3058 | food-chemistry
popcorn (kernels)
honey (jar of)
sugar (most forms)
alcohol (spirits like vodka, whiskey)
dried beans, dried lentils
I would not be planning to eat any of these stored for 25 years myself. And in general I'd suggest testing the items before trying them after 25 years or more (if you feel you must).
I would not expect cans or glass or plastic bottles of soda to be in good shape after anything like 25 years. The plastic might not survive without degrading. The can and plastic might react with the liquid over that timescale and the glass would survive but I'd be less optimistic about a sugar laced chemical soup like soda or cola not undergoing some changes. Hard to say.
If you want more info on this try this website.
Will it be ok to drink it, if it won't explode?
I would not try it. At best it soda would be flat and possibly not taste the same (chemical changes over that timescale ?) and at worst it could actually be harmful.
Exploding seems very unlikely.
Also, what about Snickers or a hamburger in a ziploc package with air sucked out of it with vacuum cleaner?
Air isn't the issue. There are bacteria that will happily live (and increase in numbers) on what's in the food. Well, it is food, after all. There are bacteria that will survive refrigeration as well. Over the timescale you're talking about I'd say it's all bets are off territory.
So: will Snickers, Hamburger in a ziploc, Bottle (or can) of Cola, all not opened, go crazy in 25 years? In 50 years?
All of those could be dangerous over such a long time period, IMO. At the very least they'd taste bad and at worst they'd kill you if you consumed them.
If so, can they go out of their packages and ruin the contents of the time capsule? If not, will it be safe to consume one of them?
Depends on the packaging. Glass would last indefinitely baring physical force or extreme of hot and cold (which might possibly cause fatigue cracking). The other wrappers would last pretty well (structurally), but 25 years is way past their design intentions. It would be a dice throw.
The following is multiple choice question (with options) to answer.
Candy disintegrates in | [
"sand",
"a pool",
"a dry bowl",
"the fridge"
] | B | sugar dissolves in water when they are combined |
OpenBookQA | OpenBookQA-3059 | food, nutrition, energy-metabolism
Title: What are the bare minimum nutrients required to survive as a human? I am trying to determine the bare minimum nutritional requirements to survive as a human, ignoring energy (caloric) requirements. Another way to ask this question is: What elements can humans not live without? I am not inquiring solely about what nutrients are needed, but also their approximate amounts.
Imagine pills that a person can take that covers all their base nutritional needs and that after taking this pill the person can eat whatever they want to meet their caloric requirements. Hypothetically, this pill could have some amount (how much?) fat, carbohydrates, protein, fiber, minerals, and vitamins, and the person could subsequently eat any other food to meet their caloric requirements knowing their nutritional needs would already be otherwise met. Lets ignore the possibility of the person suffering from health issues due to eating too much of any specific food to meet their caloric requirements (e.g., taking the magic pills and then eating only butter).
A person in this situation could think "Ok I've got most of my bases covered, now I just need to ingest another 1000 calories of (almost) anything I want).
What nutrients are absolutely necessary for humans to survive indefinitely, and how much of these nutrients are required?
I am hoping for a complete list with approximate amounts (e.g., 20g fat, 20g carbohydrates, 1mg Vitamin X, .05mg Vitamin Y, 10mg mineral X). Essential nutrients include (NutrientsReview):
Water
9 amino acids: histidine, isoleucine, leucine, lysine, methionine,
phenylalanine, tryptophan, threonine, valine
2 fatty acids (alpha linolenic and linoleic acid)
Vitamins: A, B1, B2, B3, B5, B6, folic acid, biotin, B12, C,
D, E and K (and choline, which is considered a vitamin-like substance)
Minerals: calcium, chromium, chloride, copper, iodine, iron,
manganese, molybdenum, phosphorus, potassium, selenium, sodium, zinc
The following is multiple choice question (with options) to answer.
What requires nutrients to grow? | [
"metals",
"birds",
"dirt",
"computers"
] | B | sharp beaks are a kind of adaptation for catching prey |
OpenBookQA | OpenBookQA-3060 | evolution, ornithology, ethology, sexual-selection
Bateson P. 1978. Sexual imprinting and optimal outbreeding. Nature 273, 659 - 660.
Bereczkei T, Gyuris P, Weisfeld GE. 2004. Sexual imprinting in human mate choice. Proceedings of the Royal Society of London, Series B: Biological Sciences 271: 1129–1134.
Immelmann K. 1972. Sexual and Other Long-Term Aspects of Imprinting in Birds and Other Species. In Advances in the Study of Behavior, Vol. Volume 4 of, pp. 147–174, Academic Press
The following is multiple choice question (with options) to answer.
A hummingbird will be useful to which of these things in procreation? | [
"sawdust",
"bears",
"beetles",
"cherry tree"
] | D | pollination requires pollinating animals |
OpenBookQA | OpenBookQA-3061 | inorganic-chemistry, redox, combustion
As M. Farooq pointed out a combustion reaction happens quickly, producing heat, and usually light and fire. For example, lets look at combustion reaction of an alkene (a hydrocarbon). If it is a complete combustion, the fire have a blue flame:
$$\ce{C_nH_{2n} + $\frac{3n}{2}$ O2 -> nCO2 + n H2O}$$
If it is a partial combustion, it can have a multiple $\ce{C}$ compounds as products, and have a yellow flame due to presence of elemental $\ce{C}$:
$$\ce{C_nH_{2n} + x O2 -> m C + p CO + $(n-m-p)$CO2 + n H2O}$$
where $x = \frac{2(n-p-m) +p}{2} = \frac{2n-2p-2m +p}{2} = \frac{2n-p-2m)}{2}$. In your reaction would not produce fire and it didn't use either oxygen or other oxidants ($\ce{CuO}$ is not that type of oxidant). It is true that the reaction is a redox reaction.
The following is multiple choice question (with options) to answer.
If a thing experiences a burning combustion, then it is | [
"damaged",
"fine",
"great",
"safe"
] | A | fire causes harm to living things |
OpenBookQA | OpenBookQA-3062 | general-relativity, gravity, black-holes, event-horizon, tidal-effect
And yes, you would still be able to move your body parts normally, including using your hands to turn the pages of the book.
Think of it as a really long bungee jump, but with no bungee to bring you back. Nothing can bring you back. It's a one-way trip, and the friends you left behind will never see you cross the horizon, but otherwise it's just like a bungee jump.
The following is multiple choice question (with options) to answer.
if a person looked a their head in a mirror, and moved toward it, what would happen? | [
"the head would start to grow",
"the head would disappear",
"the head would start to shrink",
"the head would explode"
] | A | as distance from an object decreases , that object will appear larger |
OpenBookQA | OpenBookQA-3063 | species-identification, botany, ecology, trees
Title: Identifying a shrub with unusual "many shoots" growth behavior While recently hiking in the southern mountains of New Hampshire, we came across a plant, and some of them were exhibiting what we interpreted to be a disease, or least unusual growth. On some of the nodes, there were a large number of extra stalks:
On each plant, the number and locations of these things varied, and not all of them had it. And we first assumed it was some ivy, or parasite, or separate plant, but it seemed pretty clear to us that it was coming right from the same branch.
We soon saw there were dead versions of this plant, and all of them had this "extra shoot" variation:
So we reasoned that no matter what this thing was -- natural variation or some kind of disease -- it was killing the plants.
Google image search was no help. It possibly identified the plant as a "viburnum", but was unable to help with the growth.
Anyone know what plant this is, or what this growth behavior is the result of? Possibly an example of a "Witch's Broom."
Witch's Broom is a deformity in plants (typically woody species) which typically causes dense patches of stems/shoots to grow from a single point on the plant. The name comes from the broom-like appearance of the stems.1
Witch's broom may be caused by many different types of organisms, including fungi, oomycetes, insects, mistletoe, dwarf mistletoes, mites, nematodes, phytoplasmas, or viruses.2
Sources:
1. Wikipedia
2. Book of the British Countryside. Pub. London : Drive Publications, (1973). p. 519
Image1. Gardeningknowhow.com
Image2. Iowa state University
The following is multiple choice question (with options) to answer.
A deer created a rose garden by | [
"pooping",
"feelings",
"time travel",
"screaming"
] | A | if seeds stick to the fur of an animal then that seed will be transported by the animal |
OpenBookQA | OpenBookQA-3064 | electrostatics, electric-current, electrical-resistance
Title: Why resistivity of copper wire is not zero even at zero kelvin?
At zero kelvin, everything seems dead stop. There is no movement occurring at zero kelvin, even at atomic level. As there is no movement in atoms, there is no vibration of atoms about their mean position (lattice sites). So, there is no inter-atomic collision. There is no collision between free electrons and atoms which the source of resistance in wire. As there is no collision among atoms or between electrons and atoms, resistance is expected to be zero. Thus, resistivity is expected to be zero. But this does not happen. There is some value of resistivity, although very less even at zero kelvin (as depicted in the graph above). What is the reason for retaining some resistivity at zero kelvin?
Layman terms used. So, correct me if necessary.... In copper there are mobile (free) electrons which are not attached to any particular nucleus and these free electrons are responsible for the conduction process in copper and other metals.
So you can think of a lump of copper as having copper ions held in position in a structure called a lattice and the ions vibrating about fixed positions.
The free electrons move around these ions within the metal just like gas molecules which are in a box.
When a voltage is applied across copper the free electrons start moving from the negative terminal to the positive terminal and in doing so gain kinetic energy.
However the free electrons do not have a free passage through the copper and collide with the vibrating copper ions losing some of their energy and making the copper ions vibrate more. Thus the temperature of the copper increases.
After a collision with a copper ion a free electron again gains kinetic energy and the process repeats itself.
The more the ions vibrate the greater the impediment to the passage of the free electrons.
So as the temperature of the copper gets less the copper ions vibrate less and so there are fewer impediments to the passage of the free electrons – the resistance of the copper is lower.
This is a simple model which does illustrate what happens but perhaps now it is better to make the model slightly more sophisticated and say that if all the copper ions in the lattice were arranged in perfect order then free electrons would not interact with the copper ions (lattice) and the resistance of the copper would be zero.
The following is multiple choice question (with options) to answer.
A live copper wire is touched to anther copper wire end to end | [
"it doubles in length",
"it melts into a puddle",
"a current can reach further",
"it breaks in half"
] | C | if one electrical conductor contacts another electrical conductor then electricity will flow through both conductors |
OpenBookQA | OpenBookQA-3065 | star, planet
Title: Why is it always planets orbiting stars? In our solar system, there are 8 planets orbiting a star, the Sun.
And I understand that there are about 500 confirmed solar systems out there.
But why is it always planets orbiting stars? Why can't it be several stars orbiting a planet, or a star orbiting a star? Why is a star by definition stationary as opposed to planets which are moving.
Of course, in that case, it wouldn't make much sense to call it a solar system, but still. "Why is a star by definition stationary as opposed to planets which are moving." This just isn't true. Both star and planets orbit a point in the system known as the barycenter (a.k.a. the center of mass of the system).
Because stars are much more massive, this barycenter is much closer to the center of the star than it is to the planets. Hence it appears to the casual observer that the less massive object orbits around the more massive object. In fact both objects orbit the barycenter. Like so:
The following diagram (seen on the wikipedia page above) shows the motion of the solar system barycenter with respect to the center of the Sun. Note that the barycenter is close to the center of the Sun, but often spends time outside the visible surface of the Sun. It follows this complicated path, mainly because of Jupiter but all the other planets make smaller contributions too.
The following is multiple choice question (with options) to answer.
what do planets orbit? | [
"volcanos",
"starlight",
"astral beings",
"people"
] | C | planets orbit stars |
OpenBookQA | OpenBookQA-3066 | climate-change, paleoclimatology, solar-terrestrial-physics
Summarizing, the IPCC consider solar irradiance variations, the timing of solar minimums and maximums. However, it consider also many other factors that also affect Earth's energy budget. Then, they do predictions based on the combined effect of all these factors. In contrast, some people tend to focus on just one factor (as solar activity) and erroneously assume that it will dominate over all the others.
For the particular case of solar activity, as you can see in the cites above. The IPCC acknowledge the possible occurrence of a solar minimum in the future, but combining all the models they conclude that there is a high confidence that its effects will be much smaller in magnitude than the projected increased forcing due greenhouse gases.
Part of the reason your question might not be well received is because it starts from an assumption that is false: "climate experts from the UN/IPCC never mention Grand Solar Minimum". They do mention it, and if you follow the references in the IPCC you will find plenty of discussion about Dalton, Maunder and older Grand Solar Minimums. And part of that discussion is to estimate the real impact that those events can have in Earth's climate. Then the IPCC get those estimates and figure out how they interplay with the many other factors that conjugate to determine current and future Earth's climate.
The following is multiple choice question (with options) to answer.
Which would likely be the biggest factor in climate change? | [
"bees",
"glaciers",
"bicycles",
"factories"
] | D | carbon dioxide concentrations in the air have increased over the last decade dramatically |
OpenBookQA | OpenBookQA-3067 | meteorology, mesoscale-meteorology
In a sense, the fact pressure at one elevation induces changes\motion in another elevation maybe shouldn't seem any less weird than the fact that a low-level low pressure system can affect the wind and weather hundreds of miles away from it horizontally. This isn't spooky action at a distance, this is a continuous fluid where changes to one part of it causes impacts on another part.
The following is multiple choice question (with options) to answer.
How is a location of lower elevation affected by flooding as opposed to a higher location? | [
"It is more affected by the flood",
"It is more resistant than a higher place",
"The lower area is drier",
"It is impossible to flood a lower elevation location"
] | A | as elevation of a place decreases , how much a flood will affect that place will increases |
OpenBookQA | OpenBookQA-3068 | soft-question, mass, metrology
So its only about 3 or 4 steps then? – PyRulez
Are you referring to the video? I'll try to clarify, your question referred to manufacturers:
How are weights and scales used by the public calibrated?
As I briefly hinted above, in every developped country there is a National Institute of Metrology and each institution " will hold several "national standard" kilograms, which are periodically calibrated against the IPK and each other."
Manufacturers make/sell a) replicas of this Secondary standards for laboratories and b) accurized scales, so, when 'the public' buys scales, they have been already tuned. Besides that, in town market-places there is usually an office of the municipal police that periodically checks the accuracy of the scales of the sellers, and where 'the public' can verify the accuracy of the weight of purchased goods.
Now, as to your follow up question: most household/ kitchen-scales can be calibrated at home if they have the 'calibrate' function/ button, like the one in the video. It is only one step: after you push the button, you put an accurate (required) weight onto it, and it authomatically calibrates itself. The only problem is to find an accurate weight: If you personally have that problem, go to a pharmacy and check your home-made sample on their precision scales and then use it at home for a couple of months.
So I presume bathroom scales are simply based on tables and spring
laws then? – PyRulez
Yes, springs are made according to Hooke's law: they are calibrated so that measured-force translates to mass at earth's gravity. They are becoming obsolete because they cannot be very accurate and they have two sources of error: the measured weight varies with the strength of the local gravitational force (by as much as 0.5% at different locations on Earth), and the elasticity of the measurement spring can vary with temperature.
Nowadays scales are usually electronic devices: if you want to know more about how scales are actually manufactured and tested, you can find plenty of details on the web: start with the quoted wiki's article and follow the links therein strain gauge, load cell, microbalance, etc.
The following is multiple choice question (with options) to answer.
A scale can measure | [
"javascript",
"intentions",
"guitar picks",
"thoughts"
] | C | a scale is used for measuring weight |
OpenBookQA | OpenBookQA-3069 | python, beginner, python-3.x
Title: Flooring cost calculator I've made a small program that calculates the cost of flooring for a given area based on the price per sqft and total sqft. I have only been programming for a few days now so I am sure that there are some things I could be doing better.
from decimal import *
import time
print("This program will help you find the cost of floor covering\n")
def program():
exit_program = ["q", "Q"]
global move_on
move_on = ["y", "Y"]
global more_info
more_info = ["n", "N"]
cost_of_tile = Decimal(input("What is the cost of the tile per square foot?"))
global answer
answer = input("Do you know how big the room is in sqft? Y/N")
if answer in move_on:
global sqft
sqft = Decimal(input("Please enter the room's size in SQUARE FEET"))
print("The cost to cover your floor will be $%s" % (sqft * round(cost_of_tile, 2)))
labor()
answer = input("Would you like to run the calculator again for another room? Y/N")
should_i_stay()
elif answer in more_info:
answer = input("Do you know the length and the width of the room? Y/N")
if answer in move_on:
width = Decimal(input("What is the width of the room?"))
length = Decimal(input("What is the length of the room?"))
sqft = width * length
print("Your room is %s sqft" % sqft)
print("The cost to cover your room will be $%s" % (sqft * round(cost_of_tile, 2)))
labor()
elif answer in more_info:
print("Sorry we need more information ")
answer = input("Would you like to run the calculator again? Y/N")
should_i_stay()
elif answer in exit_program:
print("Exiting")
exit()
The following is multiple choice question (with options) to answer.
What could be used to find out how much carpet is needed for a room? | [
"a tape measure",
"a compass",
"a barometer",
"a beam balance"
] | A | a tape measure is used to measure distance |
OpenBookQA | OpenBookQA-3070 | 1. Let total distance=X.
1st distance =30x/100.Speed=20kmph
2nd distance=60x/100 Speed=40kmph
3rd distance=10x/100Speed=10kmph
T1=1/20*30x/100 = 3x/200
T2=1/40*60x/100 =3x/200
T3=1/10*10x/100 =X/100
Applying S=D/T Formula
30x/100+60x/100+10x/100
______________________________
3x/200+ 3x/200+ X/100.
=100x*200/8x*100
=25
2. Thank you so much
3. excellent
4. Palal,post your calculation so we can rectify. It may consist a calculation error. Otherwise, answer would be same.
5. if we have taken x instead of 100, why answer doesnt comes the same way
Related Questions on Speed Time and Distance
The following is multiple choice question (with options) to answer.
Calculating a short distance can be accomplished with a | [
"yard stick",
"thought",
"touch",
"a penny"
] | A | a meter stick is used to measure length |
OpenBookQA | OpenBookQA-3071 | 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.
Bird dogs use their nose to find | [
"water foul",
"your keys",
"the Titanic",
"the menu"
] | A | smell is used for finding food by some animals |
OpenBookQA | OpenBookQA-3072 | # Mean and Median in a Classic River Crossing Problem
Consider the following classic problem:
Four people on the west side of a river wish to use their single boat to get to the east side of a river. Each boat ride can hold at most two people, and the time it takes to get across will be the time preferred by the slower occupant. The time preferences are: $1, 2, 5$ and $10$ minutes. What is the minimal amount of time in which you can get all four people across the river, where an eastbound trip must have two occupants and a westbound trip must have one occupant?
Answer: $17$ minutes. (Though many mistakenly believe it is $19$ minutes.)
Question 1: If you look at all possible ways of ferrying these four people across the river, subject to the above constraints, what would the average (mean and median) times be?
Question 2: What if you replace the time preferences with $x_1, x_2, x_3$ and $x_4$ minutes?
Question 3: What if you have time preferences $x_1, \ldots, x_n$ minutes for $n$ people, respectively?
Probably the easiest way to broach Question 1 would be to write a quick program to compute the answer, and perhaps doing this for several different time preferences would give some insight into the mean and median in the general four person case. I'm not quite sure how I would start thinking about the general $n$ person case; perhaps by solving it for $n = 1, 2, 3, 4$.
Answers (even partial ones) to any or all of my questions would be greatly appreciated!
The following is multiple choice question (with options) to answer.
Which would one most likely run into when crossing a stream? | [
"a fire",
"a piranha",
"a painful death",
"a scorpion"
] | B | aquatic animals live in bodies of water |
OpenBookQA | OpenBookQA-3073 | thermodynamics, forces, water, estimation, freezing
Here, a phase diagram for water is useful. The discussion in Powell-Palm et al.'s "Freezing water at constant volume and under confinement" includes a volume–temperature phase diagram:
From this, we can predict the equilibrium response when heating or cooling water at constant volume (by moving vertically) or compressing or expanding water at constant temperature (by moving horizontally). We find that at constant volume (moving vertically downward from 0°C and 1 g/cc), over 200 MPa and 20°C undercooling is required* to get even a 50% slush of water and ice.
Let's zoom out a little. From Powell-Palm, "On a temperature-volume phase diagram for water and three-phase invariant reactions in pure substances," we find that 209.9 MPa is ultimately required* for complete solidification, into a two-phase region (at equilibrium) of ice-Ih (ordinary ice) and ice-III:
(Note that "0.00611 MPa" should read "0.000611 MPa"—the authors missed a zero.)
We can interpret this as the compact structure of ice-III providing a solution to the problem of ice-Ih being anomalously voluminous. We find from the temperature–pressure phase diagram of water that this ice-III nucleates (at equilibrium) upon cooling to 251 K, or -22°C:
The following is multiple choice question (with options) to answer.
Freezing point is best represented by | [
"water falls",
"flowing rivers",
"glass of water",
"static ice sculpture"
] | D | flowing liquid can push objects |
OpenBookQA | OpenBookQA-3074 | thermodynamics, experimental-physics, heat-conduction
\pi
V\alpha
\frac{\mathrm{d}T}{dt}
+C_V\frac{\mathrm{d}T}{dt}
$$
Which we can simplify to:
$$
\dot U=
(\pi
V\alpha
+C_V)\dot T
$$
Where the dots denote time-derivatives.
$$
\frac{1}{\pi \alpha V+C_V}\dot U=
\dot T
$$
And if we're working with specific heat capacities:
$$
\frac{1}{\pi \alpha V + m c_V}\dot U=
\dot T
$$
This equation is general for any system with constant composition, which your bars certainly are. The term $\dot U$ is the power of your heating system. The amount of energy it dumps into your metal bar per unit of time. Presumably, it will be the same for both bars so there is no reason to simplify this further.
$$
\dot T=\frac{\dot U}{\pi \alpha V + m c_V}
$$
Presuming you'll be heating your systems using the same power source, it turns out that how fast the temperature of your bar changes is inversely proportional to both the $C_V$ and the $\alpha$.
So while it's nice that the brass will have the most pronounced expansion, making it easier to measure, that also means it would take longer to heat up, but if it's $C_V$ is much lower than that of steel, the effect is compensated and then you may be able to have your cake and eat it too as brass will both have a larger expansion and will heat up faster. It all depends on the internal pressure $\pi$.
Conceptually, the internal pressure is involved with how tightly bound are the particles in the system and it captures how difficult it is to increase the system's volume. The harder it is to increase a system's volume, the more its internal energy (and thus its temperature) decreases as its volume increases because the expansion is done against the mutual attraction of the particles that make up the material.
The following is multiple choice question (with options) to answer.
What might be created with brass? | [
"a tree",
"Light placers",
"A Cotton dress",
"Tennis shoes"
] | B | brass is made of copper and zinc |
OpenBookQA | OpenBookQA-3075 | newtonian-mechanics, projectile
Given these accelerations, along with the initial launch conditions, the paths of the putted golf balls can be determined."
My question is when does the ball stop? With the level green it is easy; the ball stops when $v_x$ and $v_y$ are both equal to zero. However, if we have straight uphill green where $\phi$ is large the ball will stop at some point on the hill, where $v_y$ is 0, but the ball will start roll back towards the starting location because of the steepness of the hill.
What is sort of speak the "end criteria"? The condition for a momentary stop is, as you say $v_x = v_y = 0$. In order for the ball to remain there indefinitely and not roll off in some direction, the acceleration of the ball must also vanish, as otherwise that acceleration will increase the velocity again.
So your condition for the final position is
$$ v_x = v_y = a_x = a_y = 0$$
(with a bit of abuse of notation).
The following is multiple choice question (with options) to answer.
What would happen if you swing at a golf ball and miss? | [
"pharmacy garbage",
"dog hair",
"loss of soil",
"soil gain"
] | C | soil loss causes grooves in soil |
OpenBookQA | OpenBookQA-3076 | 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 a dam is torn down, the beavers will | [
"play",
"relocate",
"weep",
"reconsider"
] | B | habitat destruction causes animals to move to find shelter in another habitat |
OpenBookQA | OpenBookQA-3077 | # Logic problem
##### Active member
Consider the following sequence of statements:
$$S_1: \text{at least 1 of the statements }S_1-S_n \text{ is false}\\ S_2: \text{at least 2 of the statements }S_1-S_n \text{ are false}\\ \vdots \\ S_n: \text{at least } n \text{ of the statements }S_1-S_n \text{ are false}$$
Where $n$ is some integer.
Question: for which $n$ are these statements self-consistent? In those cases: what is the truth value of each statement?
I got this off of a blog I tend to frequent. I will wait before posting the solution this time.
EDIT:
Changed the question; I had written the statements wrong
Last edited:
#### Klaas van Aarsen
##### MHB Seeker
Staff member
Suppose $k$ out of $n$ statements are true.
Then $S_1$ up to $S_k$ have to be true and the rest has to be false.
This appears to be consistent for any $n$ and any $0\le k \le n$.
##### Active member
Suppose $k$ out of $n$ statements are true.
Then $S_1$ up to $S_k$ have to be true and the rest has to be false.
This appears to be consistent for any $n$ and any $0\le k \le n$.
Sorry about that, you were absolutely right about the question as phrased.
However, this new version should prove to be a bit more interesting. This is what I had meant; I had accidentally written "true" instead of "false".
#### Klaas van Aarsen
##### MHB Seeker
Staff member
If $S_n$ is true, then $n$ statements are false, including $S_n$.
Therefore $S_n$ is false.
We now know that at least $1$ statement is false.
Therefore $S_1$ is true.
For $n=1$ this is a contradiction, and for $n=2$ this is a consistent solution.
The following is multiple choice question (with options) to answer.
Which statement is true? | [
"cans should be recycled because its materials are infinite",
"cans should be recycled because its materials are renewable",
"cans should be recycled because its materials are delicious",
"cans should be recycled because its materials are essentially finite"
] | D | aluminum is a nonrenewable resource |
OpenBookQA | OpenBookQA-3078 | dna, human-genetics, dna-sequencing, genomics
Title: Is it possible to deduce facts about a person's parents just by studying his/her genome? As an example, suppose Anne had abusive parents. Is it theoretically possible to deduce this from her genome even if she didn't inherit this quality (of being an abusive parent)? It might seem pernickety but you often can't deduce from a genome; you can only infer from it. For many characteristics about a person, there are only rough, probabilistic associations between genotype and phenotype. Not one-to-one relationships.
You can take an educated guess that someone with a certain genotype could be a social person of European ethnicity with a low risk of psychosis, which might suggest things about their parents. But there are likely many genes that influence those characteristics and still more non-genetic factors. So you couldn't be certain.
For a factor like whether the persons parents had abusive personalities, I think the genetic differences would be so subtle (if existent) and there would be so many other factors (such as the habits and choices of the parents) that you would be very unlikely to be able to draw any conclusive associations. Articles and studies about linking human genetics with a person's characteristics are listed below. If any of the genes in question are linked with those characteristics then the parents of someone with the gene could possibly have those genes and characteristics too.
Personality types including belligerence, charisma, cynicism, housekeeping, lack of personality, obsessive-compulsive behaviour and gullibility.
Psychosis and Schizophrenia risks.
Ethnicity and European ethnicity, which in turn correlate with geographical location, language and certain phenotypes.
Height.
If anyone would like to suggest additions to that list, I'll happily add them.
The following is multiple choice question (with options) to answer.
if a child gets certain traits from the parent, what delivers these to them? | [
"the epidermis of the skin",
"the platelets of the blood",
"the plasma in the blood",
"the body's nucleic acid"
] | D | offspring receive genes from their parents through DNA |
OpenBookQA | OpenBookQA-3079 | temperature, everyday-life
Title: Frosty Window Panes There might be an obvious reason for this, but yesterday, while travelling in the bus, it was heavily raining outside and the window panes becomes frosty and hazy so I could write a bunch of stuff on it. Why does this happen? That is because water had condensed onto the window pane. This water on the window pane condensed out of air. Prior to condensation, it was in the form of vapor. Now for a given water vapor pressure in air, condensation into liquid water can only occur if the temperature drops sufficiently low (to be precise, lower than saturation temperature). So rain must have cooled the window pane sufficiently for this to happen. Either that or rain increased the water vapor content of the air enough to make the corresponding saturation temperature exceed the temperature of the window pane.
The following is multiple choice question (with options) to answer.
Fogged up glass on a store window is a stage in the | [
"food chain",
"water cycle",
"life cycle",
"lunar cycle"
] | B | condensation is a stage in the water cycle process |
OpenBookQA | OpenBookQA-3080 | genetics, botany, twins
In a number of varieties, two and sometimes three megaspores were functional, giving rise to several embryo sacs. On fertilization, embryos develop in these, causing the phenomenon of pseudopolyembryony.
Therefore this source seems to agree with the first.
However, a more recent paper Martínez-Gómez, P., & Gradziel, T. M. (2003). Sexual polyembryony in almond. Sexual plant reproduction, 16(3), 135-139., focused on almonds, suggests that certain almond cultivars are prone to true polyembryony, though it seems like the additional seeds are often a bit stunted and have high mortality. They also reference a paper purporting to mention polyembryony in peach, Toyama, T. K. (1974). Haploidy in peach. HortScience, 9, 187-188., though I cannot find this article in anything but Japanese - the title, however, suggests that these may be haploid polyembryos, which also occur with the almonds - these are indeed from division of the same embryo, but because they are haploid they would not actually be genetically identical, since each is taking half of the diploid chromosomes.
With only these limited descriptions to go by, which seem to be mostly observational rather than backed by any systematic study, I would hesitantly conclude that most likely what you are seeing is a fruit in which two separate ovules developed together, and therefore could be as genetically different as any two different peaches from the same tree. True polyembryos seem to be possible in stone fruits, but as a mostly rare occurrence that is only common in particular strains - when it does occur, it may be via haploidy, which means the seeds will still be genetically distinct.
The following is multiple choice question (with options) to answer.
If a thing has both seeds and reproductive dust, it is | [
"a producer",
"a meat source",
"a consumer",
"a marine mammal"
] | A | a flower produces pollen and seeds |
OpenBookQA | OpenBookQA-3081 | optics, visible-light, reflection, refraction, lenses
Title: Why can't rainbows form at the start of a storm? I was recently at a park looking at the gorgeous scenery. I looked above and saw thick grey clouds covering up 3/4 of the sky. The sun's light is still visible for 1/4 of the sky, and it looks low enough to refract it's light through the clouds to form a rainbow. The rain started dripping slowly for 10 minutes. At five minutes I decided to take a panorama shot and ask the question, why won't a rainbow form at the start of a storm. I thought the place I was standing had the perfect condition for a rainbow to form.
Here is the panorama scene shot
There were a few rain drops pouring from the sky
The time I looked at the sky was 5:00 p.m., so the sun should be at an appropriate location.
But even if my scenario didn't give a rainbow, is this rare event still possible? The big deal with a rainbow is the angle between the sun and water droplets. The sun has to be behind you and the rainbow will occur at about 42 degrees away from the line from the sun through you. If everything lines up, you can have a rainbow at any time. (I've seen them on water spraying from a hose where things lined up just right.) This will work better when the sun in low in the sky, if the sun is too high in the sky the line from it to you goes into the ground. Since thunderstorms are often afternoon phenomenon, the sun is more likely to be low in the sky after the storm than before.
Looking at your panorama, it doesn't look like the sun was visible to you, so I wouldn't expect to see one.
The following is multiple choice question (with options) to answer.
If a sunbeam shoots through a rainstorm, | [
"hues show up",
"fields are burned",
"trees blow up",
"mice grow up"
] | A | a rainbow is formed by refraction of light by splitting light into all different colors |
OpenBookQA | OpenBookQA-3082 | the-sun, red-giant
However, even if the Earth escapes immediate engulfment, the Sun would be several thousand times more luminous than it is today, so the temperatures at the surface of the Earth could reach $>1000$ Celsius even if it stays an astronomical unit away from the Sun's surface.
A further issue is the effects of tidal dissipation. The Earth will be dragged back by tidal bulges induced in the Sun's extended envelope. The rate at which angular momentum is lost is however exquisitely sensitive to the exact radius of the Sun and the radius of the Earth's orbit, to the extent that their orders of magnitude uncertainty in whether the Earth will be dragged into the Sun's envelope even before it reaches the tip of the RGB (this is what Schroder & Smith 2008 claim) or whether the loss rates will be too low to have much effect. It all depends on how much mass loss there is (Schroder & Smith use a slightly lower estimate than above) and therefore what radius the Earth reaches and what the final radius of the Sun becomes.
At the moment I would say there is sufficient uncertainty that the fate of the Earth is undecided, but it will unarguably be uninhabitable.
The following is multiple choice question (with options) to answer.
During the summer solstice the Earth is actually what in relation to the red giant? | [
"Dying",
"Feeling sick",
"Unhappy",
"far away"
] | D | the amount of daylight is greatest on the summer solstice |
OpenBookQA | OpenBookQA-3083 | atomic-physics, geophysics, explosions
I think the most interesting diagrams are the ones labeled (e) and (f) - where the explosion happens at great depth. In that case, you get a "tight packing" of the soil above in a way that I think is similar to the mechanism that causes sugar to "settle" if you first fill a bowl to the rim, and then tap the bowl gently. The shock wave that travels through the soil (or the sugar) causes individual grains to find a more energetically favorable orientation - so they are a little more tightly packed. This can result in a crater.
Now whether you consider this "compacting voids" is a matter of opinion. But it's a real effect. Of course, very close to the nuclear reaction the heat will be so great that the rock will liquify; as a liquid it might be able to pack more tightly, although that depends on many factors.
The following is multiple choice question (with options) to answer.
A 40 foot wide hole is found in the dessert. It's shaped like a ball had hit it. What could have happened? | [
"something from space entered the atmosphere",
"a lizard built the hole",
"the moon's gravity pulled sand out of the hole",
"a dust storm filled it in"
] | A | usually craters on planets are formed by asteroids impacting that planet or moon 's surface |
OpenBookQA | OpenBookQA-3084 | materials, chemical-engineering, plastic, safety
Title: Why do glass windows still exist? (Why haven't they been replaced by plastics?) Glass is fragile and impractical to transport, install and repair. Even worse, glass kills and hurts people when it breaks. Falling to the streets like guillotines during earthquakes and bomb raids. During wars people put tape on their windows to prevent shattering. When that meteor exploded over Chelyabinsk, people got hurt by standing inside of a window watching the sky when the shock wave hit them.
There are perfectly transparent plastics, for example the PET material used to make coca cola bottles. Why aren't windows made out of that instead of glass (fragile ceramics)? It seems to be much cheaper, safer and more practical to handle. Is there any advantage at all to make windows out of glass? Is this a billion dollar business idea, and if so, why haven't anyone realized it yet? There are two main reasons why glass is still preferred over say PMMA.
The first is durability. As long as it isn't broken, the glass in a window can easily last for hundreds of years in good condition. In particular it is a lot more resistant to scratches than comparable plastics and isn't really subject to much in the way of environmental degradation. Windows are very prone to getting scratched when they are washed as they accumulate small particles of grit on their surface which gets rubbed around the surface during cleaning. Even with scratch resistant coatings no transparent plastics get anywhere near the hardness of glass.
Most glasses are also much more resistant to environmental degradation from sunlight and various chemicals in the environment. Even the most resistant plastics start to discolour and become brittle over time.
The second factor is stiffness. Glass has a much higher Young's Modulus than PMMA. In bottles etc which are stiffened by their shape this doesn't matter much but, as windows tend to be large, flat, thin panels stiffness is a big issue, affecting their ability to be sealed into their frames and their optical properties. So a plastic window would need to be substantially thicker than a glass one to have the same stiffness with consequences for optical quality and cost.
There may also be issues with gas permeability in the context of double glazed windows.
The following is multiple choice question (with options) to answer.
You can easily scratch a windshield with | [
"beach sand",
"non-abrasive sponges",
"rubber standoffs",
"prophylactics"
] | A | quartz scratches glass easily |
OpenBookQA | OpenBookQA-3085 | 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.
Regarding food, animals are | [
"decomposers",
"something else",
"consumers",
"producers"
] | C | In the food chain process an animal has the role of consumer which eats producers for food |
OpenBookQA | OpenBookQA-3086 | oceanography, rivers, satellite-oddities
Title: What are these river/canyon-like carvings in the ocean? Browsing around Google Maps, I came across this off the south-west coast of Ireland
It looks very consistent with the shape rivers and their tributaries might make, but it has me puzzled since it's all underwater!
The main, most "river-like" one is in the middle-left of the picture but there are more (which look more like fjords) at the bottom.
What caused this feature? The carvings are submarine canyons, a part of the continental slope leading from the continental shelf to the continental rise and ultimately the Abyssal plains. They are a product of :
erosion through currents and
slumping of the continental shelf
Like other erosive or slumping effects, they can be self-reinforcing, leading to canyon-like structures. The highlighted canyon here is the Gollum Channel system, seen here.
The following is multiple choice question (with options) to answer.
What are you unlikely to find in a canyon? | [
"granite",
"sandstone",
"squid",
"limestone"
] | C | a canyon is made of rocks |
OpenBookQA | OpenBookQA-3087 | organic-chemistry, combustion, environmental-chemistry, atmospheric-chemistry
I'm suspicious this may just be ethanol, but the manufacturer swears it isn't.
The advertised ratio is 1 oz to 12.5 gallons of fuel which is less than 0.1% (I believe they used double that in the tests). Too low to be ethanol anyway, right?
Follow-up:
I have confirmed that I was originally mistaken in that all measurements are ppm. I received a new copy of the original results, and $\ce{CxHy}$ and $\ce{CO2}$ are indeed measured in percent, rather than ppm. It was incorrectly rewritten in the report. The numbers are the same, though. With reference to the discussion in the question comments, this product does not appear to appreciably reduce carbon emissions in total. It does however appear to reduce carbon monoxide emissions. As carbon monoxide is a product of incomplete combustion, it is plausible that the additive is helping the fuel burn more completely. Broadly speaking, you would hope that the majority of the carbon in your exhaust gas would come out as carbon dioxide, which is 'merely' a greenhouse gas and not truly nasty like CO or PAHs. Prior to the advent of catalytic converters, carbon monoxide poisoning by vehicle exhaust was a much greater risk.
It should be noted that conservation of mass tells us some powerful things about what to expect from an engine - namely that the carbon that goes in to the engine as a component of fuel must come out as exhaust gasses, particulates, polycyclic aromatic hydrocarbons etc., or else be sequestered inside the engine (though the latter is achievable by putting a banana into the exhaust pipe, it is generally done as a prank).
Reduction of carbon emissions in general is achieved through obtaining more work per mass of fuel burnt, which, when coupled with the mass and other design features of the car confers the fuel efficiency. Unfortunately, the data provided don't tell us anything about that. The more complete burning of the fuel, evinced by the reduction of CO concentration in the exhaust gas does imply some increase in efficiency, however CO is a very small component of exhaust gas, indicating alongside the low concentration of unburnt hydrocarbons that the fuel is already burning virtually to completion.
The following is multiple choice question (with options) to answer.
If a fuel is a biofuel, it may be | [
"water",
"corn",
"sunlight",
"oil"
] | B | plants are a source of biofuel |
OpenBookQA | OpenBookQA-3088 | astronomy, everyday-life, popular-science, climate-science
It is for much the same reason that Winter is colder than Autumn, even though they have the same amount of daylight hours.
The following is multiple choice question (with options) to answer.
The reason you tend to think of the color white when you think of environments where its constantly freezing, is because those place get tons of | [
"Chipmunks",
"droughts",
"snowfall",
"monkeys"
] | C | cold environments are usually white in color from being covered in snow |
OpenBookQA | OpenBookQA-3089 | 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.
If a person restores a garden complete with oaks, then they have replaced | [
"concrete",
"jelly",
"steam",
"a resource"
] | D | An example of replacing a natural resource is planting new trees where a forest once stood |
OpenBookQA | OpenBookQA-3090 | electrical-engineering, ethics, sales, safety
But all of those steps are going way above and beyond what you're obligated to do in this particular case. This is especially so when there is a safe usage for the product along with an unsafe approach. And any of those actions are likely to irreparably damage your relationship with that client. Damaging the relationship will impair your credibility with them and make it less likely that they'll listen to your concerns.
So your obligation is to lay it out to them in unambiguous terms that you believe they need to stop using the product in their "preferred" manner and that your firm will no longer provide any support whatsoever regarding future use of that product in that configuration.
The following is multiple choice question (with options) to answer.
Doing something harmful to a person or animal will make its situation | [
"better",
"poorer",
"colorful",
"eleven"
] | B | harming something has a negative effect on that something |
OpenBookQA | OpenBookQA-3091 | rocks, remote-sensing, archaeology, ground-truth
Together, #1, #2, and #3 tell us that it's probably early summer just after the river ice has broken up.
The tooth-like features in the left image are simply erosional remnants sticking out of the riverbank. They could be bedrock (not likely), ice wedges, unmelted permafrost, or simply dirt. They are on the outside of a meander, so the river is actively cutting into them, and so the river-facing faces are quite sheer and high compared to the slopes in between. The right side might be white because the conditions there had left the snow unmelted when the image was taken. And of course their shadows are longer because the river channel is at the bottom of the bluff.
If you use Google Maps or Earth to go downriver a bit (up and to the left), you will see similar features sticking out of the riverbank, but because they're at a different angle from the features in your image, the fact that they're natural is more readily apparent.
Although the terrain is much less regular on the right side of the image, again the long shadows tell the tale. There are some round lumps that may be pingoes. The shadow that looks like a man is just a coincidental jumble of shadows from the broken terrain. If you look closely at the lump that is supposed to be the "man" (which would technically be an inunnguaq) does not have any protrusions that correspond to the "arms". The "arms" are the shadow of a little cliff or shelf past the lump, which is overlapped by the lump's larger shadow.
It's similar in effect to the infamous misinterpretation of a Viking orbiter image of a natural feature on Mars as a "Face on Mars".
This is a good example of the complications of image interpretation, specifically, understanding the conditions under which the image was taken. It's also a good time to emphasize the importance of doing ground truth when interpreting images. So when you go there, let us know what you find.
The following is multiple choice question (with options) to answer.
If you're looking for the rock between the 2nd and the 4th from our star you are looking for | [
"uranus",
"earth",
"jupiter",
"pluto"
] | B | Earth is the planet that is third closest to the Sun |
OpenBookQA | OpenBookQA-3092 | food, psychology, health, taste, children
Title: Why do children prefer sweeter foods? As we get older, we tend to lose our sweet tooth and become more tolerant to bitter foods, like vegetables. However, I never understood how this works. Why is it that children prefer sweeter foods, even some that adults may consider "too sweet"? In fact, is there any reason they would also dislike bitter foods, even when they can be beneficial to their health?
This just seems bizarre to me that the body would start out craving sweets and lose this later on. Are only humans like this? Is there anything suggesting that younger animals prefer sweet foods too, but like them less as they get older? Does this have any biological advantage or is it just random? @Colombo explains one reason that I think is obvious. However, there has been some research done on this.
One other reason is because it would provide an evolutionary advantage in environments where calories are scarce. Also, sugar actually acts like a pain reliever. Studies show that giving sugar to babies and children during surgery act like a pain reliever.
The sweet tooth could be controlled by hormones secreted from the growing bones. Some common hormones like insulin also affect sensory centers in the brain. This explains why the sweet tooth goes away as an adult.
Reference
NPR -http://www.npr.org/sections/thesalt/2011/09/26/140753048/kids-sugar-cravings-might-be-biological
The following is multiple choice question (with options) to answer.
If a person is avoiding sugar, they will stop eating | [
"meat",
"eggs",
"butter",
"bread"
] | D | carbohydrates are made of sugars |
OpenBookQA | OpenBookQA-3093 | thermodynamics, thermal-radiation
Title: Why don't gas flames radiate much heat directly, but metal objects heated by them do? Gas barbeque manufacturers place metal bars, ceramic plates or lava rocks above the gas burner so that they radiate more heat towards the grill. Cooking directly over a single gas flame just wouldn't work very well.
Why don't gas flames radiate much heat directly but a metal/ceramic object heated by the same flame does? For example, you can put your hand near a flame and not feel anything but lava rocks will scorch your skin easily. The luminous flame itself is hot; the site where the chemical process of combustion takes place. But the product of combustion, typically CO₂, H₂O, and perhaps some CO gas carry off a great quantity of the heat energy created in the reaction.
The main purpose of the lava rocks, grill etc. is to capture a good part of that heat flux so it doesn't just blow by the food into the atmosphere. Another reason is to provide a more uniform distribution over the cooking field.
The reason the lava rocks 'feel' hotter than the bare flame is that they have the capacity to store a lot of that heat. The flame and hot product gases transfer heat over time and that heat integrates over time to raise the temperature of the rocks.
The following is multiple choice question (with options) to answer.
Cooking a burger on a grill does what to the burger? | [
"makes the burger alive",
"turns the burger into groceries",
"transfers energy from the charcoal to the burger",
"freezes the burger solid"
] | C | if food is cooked then heat energy is added to that food |
OpenBookQA | OpenBookQA-3094 | evolution, definitions, artificial-selection
It does not lead to new species
In short, 1) it does lead to new species 2) the concept of species is often meaningless as poorly defined 3) evolution > speciation. In more details, below..
It does lead to new species. Different lineages of cabbage are considered different species. Cows and ox are different species. Pigs and boars are often considered different species. While wolves and dogs are considered same species, some lineages within this species (such as a Chihuahua and a Great Dane) are, I think, reproductively isolated. You might also want to have a look at the post Have we ever observed two drosophila lineages that evolved reproductive isolation in labs?
The question of whether selective breeding lead to speciation or not does not matter much on the question of whether it leads to evolution. Speciation is one outcome of evolution but is definitely not the same as evolution. Evolution does not need to lead to speciation. For example, evolution of the lactase gene in humans (see this post) did not lead to any speciation. It is still an evolutionary process.
The concept of species is mainly arbitrary. If you want to understand the concept of species, have a look at the post How could humans have interbred with Neanderthals if we're a different species?.
It decreases, rather than increases, the size of the gene pool (is this actually true?)
The following is multiple choice question (with options) to answer.
If members of a species are born then what of the species increases? | [
"food",
"populace",
"transportation",
"deaths"
] | B | if members of a species are born then the population of that species increases |
OpenBookQA | OpenBookQA-3095 | geophysics, sedimentology
Title: Does dirt compact itself over time? If so, how does this happen? If I were to bury something 10 feet (~3 metres) underground, with loose soil on top, would the ground naturally compact itself over time, until whatever I had buried has dirt tightly pressing against it on all sides?
What if I buried it 50 feet (~15 metres) underground?
If it exists, what is this compaction process called and how does it happen? Soil is a collection of various sized minerals grains, of various types of minerals produced by the weathering of rock. Typical soil minerals are clays, silts and sands.
The properties and behavior of different soil types depends of the composition of the soil: the proportion of clays, silts and sand in a soil. Sandy soils are well draining and clayey soils are sticky.
Between the grains of minerals that comprise a soil are spaces, called pores or pore spaces. The pores can be filled with either water or air, depending the location of water tables and wetting events like rain, snow melts or other forms of water inundation.
The density of a soil is dependent on the degree of compaction of the soil. For to a soil to be compacted, a stress has to be applied to the soil to realign the grains of soil which reduces the total volume of the pores and reduces the amount of air within the pores.
Consolidation of a soil occurs when pore space is reduced and water in a soil is displaced due to an applied stress.
Regarding having something buried and soil compacting around it over time, yes that will occur but it is a question of how much stress the soil experiences, the duration of time and the nature of the soil - sandy or clayey. Something buried for a day without any stresses not much will happen. But, something buried for thousands of years with people and animals walking over it, rain falling on the soil, vibrations from nearby human activity and an occasional earthquake all add to the stresses the soil will experience and increases the degree of compaction or consolidation over time.
The following is multiple choice question (with options) to answer.
What could loosen the soil by creating tunnels? | [
"candles",
"spaceships",
"love",
"rabbits"
] | D | tunnels in soil loosen that soil |
OpenBookQA | OpenBookQA-3096 | 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.
Birds in cold climates ________ by growing thick feathers | [
"migrate",
"adapt",
"die",
"reproduce"
] | B | thick feathers can be used for keeping warm |
OpenBookQA | OpenBookQA-3097 | climate-change, geography, rivers, rainfall, agriculture
Today Climate change and its consequences are some of the biggest challenges facing Humanity, with water scarcity being the big factor in Sub-Sahara Africa.
By Ultimately raising the Rainfall in the entire Southern Africa, through the managed and controlled filling and utilization of the Natural 30 000 - 60 000 square km of evaporation pans more regularly, will this not lower the extreme temperatures (day and night temperatures due to water absorbing much of the daytime heat and releasing it during the night) and drought patterns Southern Africa has experienced, and by all predictions are bound to worsen and could become more extreme?
In effect, creating a second Okavango Delta, but considerably bigger - large parts of Chobe.
A study of such a magnitude will need large amounts of research in multidisciplinary sciences, from Archaeology to Agriculture to Economics, and a much broader field of expertise - the biggest being Politics!
Could such a mammoth project not be but one small answer to a much bigger Climate Change challenge facing the Earth? (and ultimately send a bit of rain to my little piece of land in the Waterberg in the long dry winter months when we receive those dry West Winds - and fires become a serious hazard - simply by adding a bit of moisture from the vast pans Botswana are so blessed with!)
My mind has been going in circles as to the feasibility of such a mammoth, yet so cheap and easily implementable idea?
Any ideas? We agree that additional evaporation enhances energy transport from the surface to the atmosphere and intensifies the hydrological cycle and cloud formation, and that some of the most serious climate change issues such as:
The following is multiple choice question (with options) to answer.
Deserts are in extremely dry environments, so liquids will naturally be | [
"rainbow",
"plentiful",
"meager",
"talented"
] | C | a desert environment is low in availability of water |
OpenBookQA | OpenBookQA-3098 | classical-mechanics, rotational-dynamics
Title: How can earthquakes shift the earth's axis? One often comes across news articles that claim that an earthquake shifted the earth's axis.
http://news.google.com/?q=earthquake%20shifted%20OR%20shifts%20earth%27s%20axis
If you ignore the influence of other celestial bodies, an internal event like an earthquake surely can't change the direction of the angular momentum of the Earth (unless stuff is ejected out of Earth), since angular momentum has to be conserved in the absence of an external torque. So the axis has to remain fixed.
Am I missing something? Or are geologists trying to say that the resulting movement of tectonic plates causes a change in the point of intersection of the axis (which remains the same) and the plates that include the poles, so that it seems as if the axis has shifted?
EDIT
Some articles mention the value of the shift in the axis and also the change in the length of the day. If, as Ted Bunn's answer indicates below, the shift in the axis isn't actually real but is because of the movement of tectonic plates with respect to the axis, shouldn't the shift be different at the north and south poles? How are the shifts and the change in day-length calculated? Angular momentum doesn't change, but the angular velocity vector does. This is effectively due to a shift in the body's moment of inertia tensor.
The following is multiple choice question (with options) to answer.
The earth being tilted on its axis causes what? | [
"happiness",
"solar flares",
"temp changes",
"earthquakes"
] | C | the Earth being tilted on its axis causes seasons |
OpenBookQA | OpenBookQA-3099 | # Thread: Most likely of two examples
1. ## Most likely of two examples
Hi My instructor gave us two examples and posed a question:
We have a fair coin which is more likely?
1. We flip the coin 100 times and see exactly 50 heads.
2. We flip the coin 1000 times and see exactly 500 heads.
Someone in the class said immediately that 1 is more likely by a factor of sqrt(10). Why is sqrt(10) the difference? Now explanation was given.
2. ## Re: Most likely of two examples
Hint: Try calculating the actual probability using the PDF (or by using a Normal distribution approximation with continuity correction).
Have you come across using the Normal distribution to approximate a binomial distribution for large values of n?
3. ## Re: Most likely of two examples
The binomial distribution with N= 100, p= 1/2 has mean 50 and standard deviation $\sqrt{(100)(1/2)(1/2)}= \sqrt{25}= 5$. To approximate that with the Normal distribution, use a normal distribution with that mean and standard deviation and find the probability that x is between 50- 1/2= 49.5 and 50+ 1/2= 50.5.
To do the same with N= 1000, p= 1/2, mean is 500 and standard deviation $\sqrt{1000}(1/2)(1/2)}= \sqrt{250}= 5\sqrt{10}$. Find the probability of x between 500- 1/2= 499.5 and 500+ 1/2= 500.5.
The following is multiple choice question (with options) to answer.
Which is least likely to happen? | [
"a human goes from teenager to adult",
"a human goes from child to preteen",
"a human goes from teenager to child",
"a human goes from infant to toddler"
] | C | adulthood is a stage in the life cycle process |
OpenBookQA | OpenBookQA-3100 | energy, waves, energy-conservation, interference, superposition
Title: What happens to the energy when waves perfectly cancel each other? What happens to the energy when waves completely cancel each other out via destructive interference? It seems like the energy just disappears, but that would violate the law of energy conservation.
My guess is that the kinetic energy is transformed into potential energy. Or maybe what happens to the energy depends on the specific interference scenario? Can someone elaborate on that or correct me if I'm wrong? Waves always travel. Even standing waves can always be interpreted as two traveling waves that are moving in opposite directions (more on that below).
Keeping the idea that waves must travel in mind, here's what happens whenever you figure out a way to build a region in which the energy of such a moving wave cancels out fully: If you look closely, you will find that you have created a mirror, and that the missing energy has simply bounced off the region you created.
Examples include opals, peacock feathers, and ordinary light mirrors. The first two reflect specific frequencies of light because repeating internal structures create a physical regions in which that frequency of light cannot travel - that is, a region in which near-total energy cancellation occurs. An optical mirror uses electrons at the top of their Fermi seas to cancel out light over a much broader range of frequencies. In all three examples the light bounces off the region, with only a little of its energy being absorbed (converted to heat).
A skip rope (or perhaps a garden hose) provides a more accessible example. First, lay out the rope or hose along its length, then give it quick, sharp clockwise motion. You get a helical wave that travels quickly away from you like a moving corkscrew. No standing wave, that!
You put a friend at the other end, but she does not want your wave hitting her. So what does she do? First she tries sending a clockwise wave at you too, but that seems to backfire. Your wave if anything seems to hit harder and faster. So she tries a counterclockwise motion instead. That seems to work much better. It halts the forward progress of the wave you launched at her, converting it instead to a loop. That loop still has lots of energy, but at least now it stays in one place. It has become a standing wave, in this case a classic skip-rope loop, or maybe two or more loops if you are good at skip rope.
The following is multiple choice question (with options) to answer.
A light using energy can cease that activity when | [
"light bulbs are gold",
"lights are always on",
"wall switch is adjusted",
"walls are painted blue"
] | C | a switch is used to stop the flow of current in an electrical circuit |
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