source string | id string | question string | options list | answer string | reasoning string |
|---|---|---|---|---|---|
OpenBookQA | OpenBookQA-3501 | zoology, sensation
Title: Can animals that rely heavily on sonar sense colour? Apparently there're species around as rely heavily on sonar to sense the world around them.
E.g. Bat, Dolphin, Whale ...
The humans, and other terrestrial beings in a lighted world are capable of distinguishing colour in varying degrees of acuity. Is this ability to sense colour in our environment applicable to species (terrestrial, avian, and marine) that rely heavily on sonar? Any animal using sound cannot sense color though sonar directly, though these animals are not entirely blind and can probably see colors in the infrared we can't.
Even on the darkest night there is some light around and all bats use this. Old World fruit bats have colour vision, which is useful to them as they are often quite active in daytime, roosting on trees in exposed positions, rather than tucked away in dark crevices like most microbats, which can see only in black-and-white.
Dolphins have additional senses in addition to seeing they can sense electrical fields. So if an animal has its eyes covered, they will seem to be able to do things you would not expect. Its not the same as seeing the color though.
Such animals using sonar can additionally sense density and hardness as well as other material attributes which would cause the acoustic properties of the material as well as movement.
A hard-bodied insect produces a different quality of echo from one with a soft body, so bats can distinguish between some different groups of insects in this way. They can also determine the size of the object.
What's really interesting is that even human beings can experience this unusual sense. Blind people have learned to echolocate by making clicks with their mouth, and there is a movement to teach this skill.
Anyone can try it. In just an hour or two I was able to tell how close I was to a wall, whether the wall was concrete. I couldn't play video games (2:20 on the link) or see colors though.
The following is multiple choice question (with options) to answer.
If a blind person needs to know which cat has long hair and which has short hair, they can | [
"look at it",
"hear it",
"grab it",
"smell it"
] | C | touch can be used for detecting texture |
OpenBookQA | OpenBookQA-3502 | desert
Title: When was the first not-icy desert formed? For how long have deserts existed and which one would be the first to be created? I'm talking about arid, dry deserts, not the Antarctic or Arctic or any other icy deserts. Deserts have existed since at least the Permian period (299-251 million years ago) when the world's continents had combined into the Pangaea supercontinent. Stretching from pole to pole, this land mass was large enough that portions of its interior received little or no precipitation, according the University of California Museum of Paleontology.
Pangaea broke into smaller land masses which were moved across the surface by tectonic forces, a process that both changed global climate patterns and the climate those continents were exposed to. As a result, current desert regimes date back to no more than 65.5 million years, according to this Encyclopedia Britannica article:
The desert environments of the present are, in geologic terms,
relatively recent in origin. They represent the most extreme result of
the progressive cooling and consequent aridification of global
climates during the Cenozoic Era (65.5 million years ago to the
present), which also led to the development of savannas and scrublands
in the less arid regions near the tropical and temperate margins of
the developing deserts. It has been suggested that many typical modern
desert plant families, particularly those with an Asian centre of
diversity such as the chenopod and tamarisk families, first appeared
in the Miocene (23 to 5.3 million years ago), evolving in the salty,
drying environment of the disappearing Tethys Sea along what is now
the Mediterranean–Central Asian axis.
Which would put the oldest of "modern" desert somewhere in the region of what later became North Africa or South Asia.
The following is multiple choice question (with options) to answer.
The grand canyon was formed by the colorado river doing what over a long period of time? | [
"vaporizing",
"evaporating",
"freezing",
"circulating"
] | D | the Grand Canyon was formed by the Colorado River flowing over long periods of time |
OpenBookQA | OpenBookQA-3503 | botany, ecology, energy
Title: Why do plants create enough energy for the entire ecosystem? In my environmental class, we were recently learning about the $10\%$ law that basically says only $10\%$ of the energy goes from one trophic level to the next.
This got me thinking about why energy flows from one level to the next. Specifically, why do plants create enough energy for the entire ecosystem? Wouldn't they do fine without us, and wouldn't that save them the work of creating all that excess energy? Plants collect energy for themselves via photosynthesis, not for others.
It is used for it's own growth and survival.
It's energy is then redistributed to other organisms when either the plant dies and decomposes or when it is consumed. Many organism cannot collect their energy like plants do, and thus must feed on organisms (like plants) that are able to collect and store energy. This is in many cases detrimental to the plant (it should be intuitive why being eaten might be bad), and many, many plants do have traits to discourage other organisms from eating them (plants with toxins, thorns, etc.).
The following is multiple choice question (with options) to answer.
Plants are called producers because they may produce their own | [
"time travel",
"feelings",
"vortex",
"sustenance"
] | D | In the food chain process a green plant has the role of producer |
OpenBookQA | OpenBookQA-3504 | 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.
If the pressure alters from a high pressure system, the most likely thing to occur next will be | [
"sunshine",
"picnics",
"sprinkling",
"beaches opening"
] | C | as air pressure decreases , the chance of rain will increase |
OpenBookQA | OpenBookQA-3505 | thermodynamics, everyday-life, water, phase-transition
Title: Why does water boil in bubbles? When my glass kettle is boiling water, you can see all the bubbles going up in a line.
Why do bubbles originate from a selected group of points on the bottom of the kettle? Why isn't it random?
What force prevents the gas of the water going up until it reaches a visible bubble size? Why there are only dozens of bubbles and not millions of tiny bubbles?
The following is multiple choice question (with options) to answer.
Water is bubbling. What characteristic is it likely to have? | [
"intense heat",
"cool water",
"melted water",
"easier to transport"
] | A | if liquid is boiling then that liquid is hot |
OpenBookQA | OpenBookQA-3506 | entomology
Title: What is the name of this tiny creature? It looks like a tiny piece of moving cotton? By chance, I saw this tiny insect on my bag a few days ago in Sydney. Am I the first person who has pinpointed this animal?! If not can you please let me know its name? From your image, it looks like it might be a woolly aphid. I just did a bit of cursory research, and it looks like they're often described as floating pieces of fluff, that seem to wander instead of directly heading somewhere. The fluff on their back is actually wax produced as a defense mechanism from predators and the like. I hope this is what you were looking for!
The following is multiple choice question (with options) to answer.
A creature wanting heat will want to make its home | [
"somewhere wet and foggy",
"deep in the rainforest",
"a place where water is sparse",
"somewhere with a lot of insects"
] | C | a desert environment is usually hot in temperature |
OpenBookQA | OpenBookQA-3507 | sun
Title: Is there an instance where the sun sets or rises partly, then return back? I am reading Longest Sunset from XKCD. At first, I've thought that he mentions these phenomena just for fun, but it turns out to me that it might happens, based on the level of somewhat seriousness that I perceive from his writing. He doesn't talk about that in detail.
For the sunset:
Sunset starts the instant the Sun touches the horizon, and ends when it disappears completely. If the Sun touches the horizon and then lifts back up, the sunset is disqualified.
I'm not sure if the sunset is disqualified is because it happens, but we don't count it, or because he's just making fun. But I can't prove that this cannot happen. The more we head to the poles, the shorter the night is. Ultimately there will be a point that the sun still sets, but not completely, right?
For the sunrise:
For the purposes of our question, this is not a sunset:
The phrase for our purposes strengthen my doubt that he is being serious. The logic is the same above.
But these two illustrations are in the series of other apparently amusing ones, which are the sun as the cell in division, or as the egg in hatching (if you read the book, you will see this effect stronger).
So, is there an instance where the sun sets or rises partly, then return back? Yes, such sunrises happens every year at the beginning and end of the polar nights at high latitudes. One can have a few days with a glimpse of the sun but disqualified sunsets and sunrises.
Sunsets occur at the end of the midnight sun period by the end of the summer, the first sunset is not complete.
Sun at it's highest elevation at midday. (To be honest, the picture might be taken the day after the first sunrise, as some mountains are hiding the horizon.)
Here is e.g. an article from Svalbardsposten, the northernmost newspaper in the world, reporting of the first rays of sunlight after the polar night and some pictures from the last sunrise/sunset before the polar night in northern Sweden.
The same occurs at the southern polar circle and south thereof, unless it's cloudy...
Update: here is a great time laps from Davis Station in the Vestfold Hills showing exactly what you asked about: Mid winter
The following is multiple choice question (with options) to answer.
You'll know that the sun has set if | [
"a baby is sleeping",
"all the birds are silent",
"the temperature has gone down",
"the brightest thing in the sky is a satellite"
] | D | if it is night then the sun has set |
OpenBookQA | OpenBookQA-3508 | 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.
A plant would prefer | [
"orange juice",
"Dasani",
"apple juice",
"fire"
] | B | a plant requires water to grow |
OpenBookQA | OpenBookQA-3509 | atmosphere, clouds, fluid-dynamics
Title: What affects the surface characteristics of cumulus clouds? I love looking at clouds. I love trying to describe them and compare what I see day to day.
I have dozens of questions about the things I’ve observed and I would really like to understand the physics of the world around me. Today I would like to focus on the surface dynamics of cumulus clouds.
Why do some cumulus clouds have distinct textured surface while others are softer and wispy at the edge?
I imagine it probably comes down to temperature and pressure. It may also be an effect of direct sunlight, I’m not sure. I notice the soggy cotton clouds are more common in the evening and the billowy ice cream clouds are more common mid-day.
Do clouds have surface tension like liquid water?
Does the flow of water either into or out of a cloud affect its surface characteristics? No, clouds don't really have a 'surface' that could have tension like a body of water. The different looks in these two examples (left Cumulonimbus Calvus and right Cumulus Humilis) are greatly dependent on how they have formed and how are they evolving now.
The large Cumulonimbus is still growing in a relatively rapid speed. The cloud is reaching higher and higher upwards carrying moist air. The moist air due to turbulent flows and expanding of the rising air gets mixed with the cold air and instantly forms/extends cloud as it reaches saturation (saturation is reached with less water in colder air and air is colder in higher altitudes). If there wasn't the expansion then flows of dry air to the cloud would desaturate the cloud and more small scale variation could be seen as in the Cumulus Humilis. Also the Cumulonimbus being much larger and further away looks different just due to distance. The steady state like situation of the Cumulus Humilis where it isn't growing (perhaps a little on the top) and the fact that the lower atmosphere has stronger turbulent motions equals to the appearance where more cotton candy pieces 'drift' from the cloud.
The following is multiple choice question (with options) to answer.
Fluid from clouds tends to increase | [
"animal hydration",
"animal perspiration",
"plant thirst",
"animal thirst"
] | A | as the amount of rainfall increases in an area , the amount of available water in that area will increase |
OpenBookQA | OpenBookQA-3510 | astronomy, everyday-life, popular-science, climate-science
Title: Why is the summer, in the temperate latitudes, in average, hotter that the spring? It is common knowledge that the transition from the Spring to the Summer season occurs in the Summer Solstice when the "Sun reaches its highest excursion relative to the celestial equator on the celestial sphere" (as stated in Wikipedia).
It is also stated in Wikipedia' Summer page:
"Days continue to lengthen from equinox to solstice and summer days progressively shorten after the solstice, so meteorological summer encompasses the build-up to the longest day and a diminishing thereafter, with summer having many more hours of daylight than spring."
My question is: why is the summer, in the temperate latitudes, in average, hotter that the spring? A major part of the reason for this is due to the temperature of the ground. While the length of days in the Summer are effectively a mirror of those in Spring, you must take into consideration more than that.
When Spring commences in temperate climates, it is (usually) immediately preceded by winter. Due to the Winter, the ground and/or surrounding bodies of water are very cold. This has the effect of cooling the air for the first part of Spring while the ground/water begins to thaw/warm up. Furthermore, it takes much longer to warm or cool a body of water than a mass of air; even longer to warm or cool the ground and water. Therefore, as Spring progresses and the days become longer (also meaning the Sun is higher above the horizon, thus providing more heating power), the sunlight must first overcome the cooling effects of the ground and water bodies. Near the end of Spring - when the days are sufficiently long and the Sun is much higher above the horizon - you should notice the weather becoming hotter. This is because the ground and water has had time to warm up, which means it is not constantly cooling the air and making it feel colder.
When you then transition to Summer, the ground is already sufficiently warm but the days are still long and the Sun is still high in the sky. This means the Sun can heat the ground, water, and air even more and without any cooling effects. This allows the Summer temperature to be easily higher than that of the Spring temperatures. If Summer were immediately preceded by winter, you might notice the weather getting warmer much more quickly, but the average temperature would be very close to that of the Spring.
The following is multiple choice question (with options) to answer.
Why would it be summer one day and fall another day? | [
"the earth's position compared to the sun has shifted",
"rain has started falling",
"leaves have fallen from the trees",
"the squirrels are gathering nuts"
] | A | Earth orbiting the Sun causes seasons to change |
OpenBookQA | OpenBookQA-3511 | seismology, earthquakes, seismic-hazards, drilling
Title: Why aren't seismic stations installed very deep underground so as to pre-warn from earthquakes? The velocity of p-waves emanating from earthquakes is in the range of 5-8 km/s (link)--let's assume it is 5 km/s. The earthquake depth is up to hundreds of kms deep underground (link)--let's assume it is 100 km.
That said, if a seismic station is installed at a depth of 50 km, and there are many of them in any given metropolitan area, then we can have a warning that is tens of seconds before the earthquake reaches the surface.
While I realize that drilling down to 50 kn is no easy task, I would have imagined that saving human life is well worth the efforts. Why hasn't this been done so far? Is it that such a short notice (10s of seconds) isn't worth it? The simple answer is that you can't drill to 50 km depth.
The deepest holes ever drilled were to a little more than 12 km, one is named the Kola Superdeep Borehole in Russia, which was a scientific drilling project. The very few others were oil exploration boreholes.
Drilling that deep is extremely expensive and hard. If you go and ask anyone who ever worked on a drill rig, drilling the second 100 metres is always harder than the first 100 metres. And we're talking about kilometres here! There are several problems with drilling that deep. It's extremely hot down there, and the drilling equipment just breaks and stops working. You also need to pump cooling water in and pump out the stuff you're drilling and it gets harder with depth.
This is simply not feasible. Now let's say that you did somehow manage to drill a hole to that depth. How would you put monitoring equipment inside? That equipment has to sustain heat and pressure and still keep working, while being able to transmit whatever it's reading back to the surface. This is not going to happen, not at 50 or 10 km depth.
Another problem is that not all earthquakes are that deep. Some earthquakes originate near the surface, or just several km deep. Having a monitoring station down there isn't going to help. The 2011 Tohoku earthquake (the one that triggered the tsunami at Fukushima) was only 30 km deep. Same thing for the 2004 Indian Ocean earthquake.
The following is multiple choice question (with options) to answer.
Earthquakes can devastate an area even though they usually last | [
"half an hour",
"half a minute",
"30 minutes",
"20 minutes"
] | B | an earthquake usually occurs over a period of 10 to 30 seconds |
OpenBookQA | OpenBookQA-3512 | thermodynamics, energy, power
Toyota Corolla, 13 gallon tank, 20% efficiency, 103 kWh usable energy
Tesla Roadster, 56 kWh battery capacity
Chevy Volt, 16 kWh battery capacity
If we compare a liquid Nitrogen car to the Chevy Volt it might not be so bad. But why would we do that? That car can still augment its range with gasoline. A part of the argument for electric cars is that you don't have the same energy loss from idling. Would that be true for a liquid Nitrogen car? There is no reason to believe that.
Let's say we assume a reasonable efficiency of half the isothermal process, which is illustrated in Figure 2 of the reference. Let's also say we'll hold 50 kWh of usable energy in the tank (even though this could still cause range problems). We've increased the tank size by a factor of 4 and the weight of the full tank is now around $1000 kg$. This is close to what many cars weigh.
The energy content relative to gasoline, as well as the alternatives, kills the idea. It would seem to require extremely optimistic assumptions to make it a reasonable proposal before we even get into the discussion about infrastructure needed to make it happen. The most fair comparison would be to other cars that also use alternative fuels, but it fails there too. EVs seem to have better viability on the basis of simple energetics. Maybe you're concerned that we'll run out of Lithium. A vehicle powered by compressed natural gas (not even the super-high pressure tanks that many have hope in) would blow it away, and the tank would be more manageable. Plus the fuel would be (dramatically) cheaper. Plus the infrastructure would be there. Plus, the engine is a proven design. We could do better with coal-to-liquids, we could probably do better with biofuels.
The following is multiple choice question (with options) to answer.
As vehicles become more efficient petro consumption | [
"increases",
"stops",
"decreases",
"stay the same"
] | C | as mileage per galon of gasoline increases , the amount of gasoline used will decrease |
OpenBookQA | OpenBookQA-3513 | javascript, performance, beginner, game, canvas
// Following code is a fix for [[obj1, obj3], [obj2, obj4]].
if (alreadyHadCollisions && (index1 > -1 || index2 > -1)) {
for (i4 = 0; i4 < this.collisions[collisionIndex].length; ++i4) {
obj3 = this.collisions[collisionIndex][i4];
if (obj3 !== obj1 && obj3 !== obj2) collision.push(obj3);
}
this.collisions.splice(collisionIndex, 1);
}
if (index1 > -1 || index2 > -1) {
alreadyHadCollisions = true;
collisionIndex = i3;
}
}
if (!alreadyHadCollisions) this.collisions.push([obj1, obj2]);
}
}
}
}
for (i1 = 0; i1 < this.collisions.length; ++i1) {
var targets = this.collisions[i1],
biggestRadius, scaleFactor;
obj1 = targets[0];
biggestRadius = obj1.getRadius();
for (i2 = 1; i2 < targets.length; ++i2) {
obj2 = targets[i2];
var density = Math.max(obj1.density, obj2.density),
area = obj1.getArea() * (obj1.density / density) + obj2.getArea() * (obj2.density / density);
The following is multiple choice question (with options) to answer.
Tearing an object changes that object's what? | [
"heat",
"liquid",
"entire appearance",
"shape keys"
] | C | tearing an object changes that object 's shape |
OpenBookQA | OpenBookQA-3514 | the-moon
Title: moonless night and lunar phase How to define moonless night? There is no moon at all during some night?
How to calculate and know whether the moon would appear during one night?
If the lunar phase is full moon, is it possible that the moon will not appear ? A moonless night is, as you suspect, a night in which the Moon does not appear visible in the sky. This happens once per month, when the Moon is near the Sun. Due to the proximity of the Moon and the Sun in the sky, at that time the Moon is the smallest sliver possible, and therefore not a full moon.
This is because it is actually the Sun that illuminates the Moon, and when the Sun and the Moon are in the same direction in the sky we are seeing the non-illuminated side of the Moon. Note the direction of the sunlight in this image:
Obviously, the direction of the sunlight is the direction of "up" during the day. If you look at the horizon slightly after sunset or slightly before sunrise, you might actually catch a glimpse of the sliver of Moon before it set or rises slightly after or before the Sun.
The following is multiple choice question (with options) to answer.
After the moon phase where you can see nothing of the moon, what comes next? | [
"the full moon",
"the last quarter",
"the first quarter",
"the half moon"
] | C | the first quarter phase of the moon occurs after the new moon |
OpenBookQA | OpenBookQA-3515 | zoology
From Scripture's research: “. . . a live frog can actually be boiled without a
movement if the water is heated slowly enough; in one experiment, the
temperature was raised at the rate of 0.002 degrees Celsius per
second, and the frog was found dead at the end of 2.5 hours without
having moved."
According to Dr. Karl S. Kruszelnicki (Australian scientist): "[T]he numbers just don’t seem right. If the water comes to a boil,
that means a final temperature of 100 degrees Celsius. In that case,
the frog would have to have been put into the water at 82 degrees
Celsius. Surely, the frog would have died immediately."
According to Dr. Victor H. Hutchinson (Herpetologist and Zoology Professor at University of Oklahoma):
"The legend is entirely incorrect! The 'critical thermal maxima' of many species of frogs have been
determined by several investigators. In this procedure, the water in
which a frog is submerged is heated gradually at about 2 degrees
Fahrenheit per minute. As the temperature of the water is gradually
increased, the frog will eventually become more and more active in
attempts to escape the heated water. If the container size and
opening allow the frog to jump out, it will do so."
Whit Gibbons (University of Georgia) says that there is an important message behind the false legend:
So where does that leave us with the boiling frog as a metaphor for
the human response to economic change or environmental degradation?
Well, it's not true that you can induce a frog to willingly remain in
boiling water by starting it off in cold water. But that does not
diminish the truth of the message that the accumulation of
imperceptible changes can have a significant effect on the economy and
the environment. We need to be aware of what changes are occurring and
to respond to them in a timely fashion. The metaphor lies in the
frog's ability to escape from the container: if there's no way out,
then the frog's fate is a foregone conclusion.
The following is multiple choice question (with options) to answer.
A komodo dragon's body temperature would be highest if immersed in | [
"lava",
"apple juice",
"liquid nitrogen",
"water"
] | A | an island is formed by lava cooling on the ocean floor over time |
OpenBookQA | OpenBookQA-3516 | inorganic-chemistry, acid-base, everyday-chemistry
$$\ce{H2O + CO2(aq) <=> H2CO3}$$
and the protolysis of true $\ce{H2CO3}$
$$\ce{H2CO3 <=> H+ + HCO3-}$$
For a weak acid
$$\begin{align}
\log[\ce{H+}]&\approx\frac12\left(\log K_\mathrm a+\log[\ce{H2CO3^*}]\right)\\
&=\frac12\left(-6.3-5.0\right)\\
&=-5.65\\
\mathrm{pH}&=5.65
\end{align}$$
Thus, pure rain in equilibrium with the atmosphere has about $\mathrm{pH}=5.65$. Any acid rain with lower $\mathrm{pH}$ would be caused by additional acids.
The following is multiple choice question (with options) to answer.
If a person is going to be in an area with acid rain, the organs in the body can be unharmed because of | [
"outer organ protection",
"being given immunity",
"using sunscreen",
"taking vitamins"
] | A | skin is used for protecting the body from harmful substances |
OpenBookQA | OpenBookQA-3517 | thermodynamics, evaporation, gas, liquid-state
On the water surface, knowing the temperature, we can estimate the vapor pressure and vapor mixture fraction. Then there will be an diffusion process for the water vapor to move out and for the ambient air to move in. Because the water surface doesn't allow the air to further move, a circulation forms. When the water vapor moves out, the water vapor pressure drops, so more liquid water evaporates to fill up the loss of water vapor. The evaporation associates latent heat so water surface area temperature drops (you may see dew on the bowl wall). Then a heat transfer process starts which may initiate water circulation as well.
As this is complex, doing test might be a quick way to get the K value if you assume it is a constant, which is questionable.
The following is multiple choice question (with options) to answer.
You can experiment with seeing evaporation by using | [
"magic",
"uncovered mason jars",
"nothing",
"time travel"
] | B | evaporation causes amount of water to decrease |
OpenBookQA | OpenBookQA-3518 | microbiology, bacteriology, ecology, environment, freshwater-biology
Title: Does rainwater contain many fewer micro-organisms than river water? From watching many documentaries on micro-organisms, I can tell water typically contains quite a lot of them.
But what about rainwater? (before it hits the ground). I know nothing about any micro-organisms that live in the sky or clouds. Does rainwater contain fewer, and less dangerous, micro-organisms? According to a number of citations listed on Kenyon College's MicrobeWiki, rain can contain microorganisms via a process called "bioprecipitation."
Essentially, microorganisms, dust and other small particles get swept up into the atmosphere, and cold temperatures cause atmospheric water vapor to freeze around the organism/particle. Once the ice-covered particle picks up enough mass, it falls from the sky and reaches earth as precipitation (likely rain if temperature is warm enough).
Here is a schematic from Wright et al. (2104) of how an increase in relative humidity, due to a cold-frontal passage, can trigger biological ice nuclei release followed by seeding of the frontal cloud band with the lofted ice nuclei:
So How Many (and Which) Bacteria Are in Rain?
Which Bacteria?
According to Wikipedia:
The ice-nucleating bacteria currently known are mostly plant pathogens
According to MicrobeWiki, these include:
Exserohilum turcicum, Pseudomonas viridiflava, Pseudomonas fluorescens, Pantoea agglomerans and Xanthomonas campestris.
The most well described organism that demonstrates ice nucleation is Pseudomonas syringae, which was determined to specifically supply a source of ice nucleators by Leroy Maki in the 1970’s.
According to work by Natasha DeLeon-Rodriguez, Athanasios Nenes, et al. (full paper here and NPR story here), 100s of species of bacteria exist in the clouds and it's not uncommon to find almost 20 species in any given sample (60% of which on average were still living).
Here's a graph showing the relative amounts of various taxa found in their samples:
The following is multiple choice question (with options) to answer.
Which area contains few organisms? | [
"Madagascar",
"South Pole",
"Amazon Rain Forest",
"Sahara Desert"
] | B | cold environments contain few organisms |
OpenBookQA | OpenBookQA-3519 | neurotransmitter, pharmacology, receptor, serotonin
Title: Do SSRIs downregulate or upregulate the 5-HT3 receptor? What effect do SSRIs have on the expression of the ligand-gated ion channel, the 5-HT3 receptor? There are five subunits to this receptor (5-HT3), which are encoded by the genes HTR3(A-D) and differentially expressed depending on cell location in the (human) body. In contrast to the information in the previous answer, my first source actually has shown HTR3A to be most highly expressed in the CNS. The others are almost exclusively found in cells of the gut.
My second source reveals that the 5-HT3A receptors are up-regulated (show increased expression) on the cell surface in the presence of agonists and antagonists to the receptor. So, if an agent was increasing the amount of 5-HT (serotonin, an agonist) outside the cell, as would an SSRI, the expression of the receptor subunit-encoding genes would be expected to increase.
Niesler, B., Frank, B., Kapeller, J. & Rappold, G. A. Cloning, physical mapping and expression analysis of the human 5-HT3 serotonin receptor-like genes HTR3C, HTR3D and HTR3E. Gene 310, 101–111 (2003).
Morton, R. A., Baptista-Hon, D. T., Hales, T. G. & Lovinger, D. M. Agonist- and antagonist-induced up-regulation of surface 5-HT3 A receptors. Br. J. Pharmacol. 172, 4066–4077 (2015).
The following is multiple choice question (with options) to answer.
Which promotes the creation of serotonin? | [
"Jupiter",
"Venus",
"the Sun",
"the Moon"
] | C | sunlight contains ultraviolet light |
OpenBookQA | OpenBookQA-3520 | 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.
When taking a pickax to rocks | [
"pick a location where lots of people will be",
"sweep up after yourself to keep the workplace safe",
"eschew wearing any safety gear",
"clean up is an unnecessary chore"
] | B | breaking apart rocks can cause debris |
OpenBookQA | OpenBookQA-3521 | energy, visible-light
You can see the "brightness" at the end of the fiber - the construction (with graded index along the sides) drives all the light to this one interface where the light can escape.
The following is multiple choice question (with options) to answer.
What gives off light? | [
"scorching logs",
"dirt",
"water",
"fire drills"
] | A | fire gives off light |
OpenBookQA | OpenBookQA-3522 | species-identification
Title: What is this (water-loving) bug? For some time we've been finding these little fellows in our apartment:
They seem harmless enough, but finding them is a bit... annoying. I found the fellow above in the bathtub, and it's not uncommon to find more than one.
Unfortunately, some started to appear near the kitchen sink as well. Or outside of the bathroom on the floor (at least that's where we noticed them).
I think this thing prefers darkness over light, and seems to be drawn towards wet places or just water. These critters are also surprisingly fast.
What is it? Should we be concerned about a pest problem, or is this just a minor, unwelcome guest?
PS. We live in Poland. It is a Lepisma saccharina or silverfish.
It is rather common and yes, it's harmless.
The following is multiple choice question (with options) to answer.
Which creature would be safest from predators in its natural underground habitat? | [
"eagles",
"lizards",
"moles",
"sardines"
] | C | omnivores eat plants |
OpenBookQA | OpenBookQA-3523 | homework-and-exercises, newtonian-mechanics, forces, string, rigid-body-dynamics
For completeness, here's the full solution. There are two tension forces in the string, one for the hanging part and one for the horizontal part, because the rope is not sliding along the pulley but turning it. The net torque (about the center of mass, with positive clockwise rotation sense) on the pulley is
$$
\tau_{\textrm{net}} = \tau_{\textrm{hor. rope}} + \tau_{\textrm{ver. rope}}
= T_{\textrm{hor}}R - T_{\textrm{ver}}R\,
$$
leading to the rotational form of the second law, given by
$$
I \alpha = \tau_{\textrm{net}} = T_{\textrm{hor}}R - T_{\textrm{ver}}R\,.
$$
For the hanging mass, Newton's 2nd law takes the form
$$
ma = T_{\textrm{ver}}-mg\,,
$$
with up being the positive direction. This is now two equations with four unknowns ($a$, $\alpha$, and the two tensions). There is a relationship between $a$ and $\alpha$ due to the rope not slipping along the cylinder, and the tension force $T_{\textrm{hor}}$ in the horizontal part of the rope is just $F_0$, using Newton's 3rd Law.
The following is multiple choice question (with options) to answer.
A pulley is used to lift a flag on a flagpole by | [
"putting something in the air",
"yanking string up a wheel",
"moving a rope sideways",
"moving things with wheels"
] | B | a pulley is used for lifting objects |
OpenBookQA | OpenBookQA-3524 | homework, plant-physiology, plant-anatomy
and 'Vascular Plants = Winning! - Crash Course Biology #37'
https://youtu.be/h9oDTMXM7M8?t=373
[5] Osmosis (water compensating solutes) "In Da Club - Membranes & Transport: Crash Course Biology #5"
https://youtu.be/dPKvHrD1eS4?list=PL3EED4C1D684D3ADF&t=148
Ian (and dad <= all errors and approximations are his :) ).
The following is multiple choice question (with options) to answer.
plant stem is the vehicle for transporting water and food from roots to the rest of the | [
"solar harnessing life",
"cupcake",
"rock",
"sneaker"
] | A | a plant stem is the vehicle for transporting water and food from roots to the rest of the plant |
OpenBookQA | OpenBookQA-3525 | astronomy, everyday-life, popular-science, climate-science
Title: Why is the summer, in the temperate latitudes, in average, hotter that the spring? It is common knowledge that the transition from the Spring to the Summer season occurs in the Summer Solstice when the "Sun reaches its highest excursion relative to the celestial equator on the celestial sphere" (as stated in Wikipedia).
It is also stated in Wikipedia' Summer page:
"Days continue to lengthen from equinox to solstice and summer days progressively shorten after the solstice, so meteorological summer encompasses the build-up to the longest day and a diminishing thereafter, with summer having many more hours of daylight than spring."
My question is: why is the summer, in the temperate latitudes, in average, hotter that the spring? A major part of the reason for this is due to the temperature of the ground. While the length of days in the Summer are effectively a mirror of those in Spring, you must take into consideration more than that.
When Spring commences in temperate climates, it is (usually) immediately preceded by winter. Due to the Winter, the ground and/or surrounding bodies of water are very cold. This has the effect of cooling the air for the first part of Spring while the ground/water begins to thaw/warm up. Furthermore, it takes much longer to warm or cool a body of water than a mass of air; even longer to warm or cool the ground and water. Therefore, as Spring progresses and the days become longer (also meaning the Sun is higher above the horizon, thus providing more heating power), the sunlight must first overcome the cooling effects of the ground and water bodies. Near the end of Spring - when the days are sufficiently long and the Sun is much higher above the horizon - you should notice the weather becoming hotter. This is because the ground and water has had time to warm up, which means it is not constantly cooling the air and making it feel colder.
When you then transition to Summer, the ground is already sufficiently warm but the days are still long and the Sun is still high in the sky. This means the Sun can heat the ground, water, and air even more and without any cooling effects. This allows the Summer temperature to be easily higher than that of the Spring temperatures. If Summer were immediately preceded by winter, you might notice the weather getting warmer much more quickly, but the average temperature would be very close to that of the Spring.
The following is multiple choice question (with options) to answer.
When is hotter? | [
"desert",
"night",
"morning",
"noon"
] | D | the sun is located directly overhead at noon |
OpenBookQA | OpenBookQA-3526 | 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.
Prolonged sweating in hot weather means | [
"your going to change into a new animal",
"you're ready to travel through time",
"you are going to fill a swimming pool",
"your organs are unable to get replenished"
] | D | if an organism becomes too hot then that organism may die |
OpenBookQA | OpenBookQA-3527 | fluid-dynamics, everyday-life, water
As can be seen from these photos, the colour dye is present in the water jets which recoil off the surface of the transparent pool water. However, not all of the water in the jets is from the coloured drop. Some of the original drop is trapped in a pocket below the surface, with the rebounding 'jets' having a 'coating' of the original drop material. The way we know this is because in the experiment, the coloured drop was made from water mixed with thymol blue, an indicator which is dark orange in colour at neutral-to-acidic pH. The pool water contained 0.1% sodium carbonate (alkali), which is transparent in colour, but when the two combined, the mixture turns blue in colour.
Some fascinating insight into the phenomenon can be gained by examining some high speed video footage.
If you look at this high speed video, you will see that when the water droplet falls into the water, it appears to bounce back out!
An even better example of the 'bouncing' phenonenon can be found in this video, when the drop is released gently from close to the surface of the water, it appears that after the drop is 'coalesced' into the water, part of it 'bounces' back out as a smaller droplet, which the falls back and floats on the surface of the water.
The explanation offered is that a layer of air gets trapped beneath the droplet as it hits the surface of the water. Some of the water in the droplet gets coalesced into the pool by the water tension, releasing a smaller droplet back out.
The following is multiple choice question (with options) to answer.
An orange liquid surfaces when | [
"A volcano suddenly explodes",
"Someone buries a chest",
"Someone starts a fire",
"People dig for wells"
] | A | magma is found below the ground |
OpenBookQA | OpenBookQA-3528 | evolution
///
Why not have a switch between the two hemispheres to give the hand currently being used the fine motor skill located in the other hemisphere? (from comment)
I see. In my answer I only talked about one aspect. The brain doesn't have to learn skills for each hand completely independently. For example imagine if you learn to play a musical piece with your right hand only. If you try it with your left you won't be amazing but you'll definitely be better than a complete novice. Our brain can learn how to do by seeing which is vital for development. But there's a limit to that, your hands aren't completely identical so there's still a portion that needs fine tuning. Your muscles have different stregth, fatigue, resistance, recruitment patterns, places they innervate. Your hands are mirror images. The weight of your hand is different. And not only that but these variables aren't fixed, there's lots of them and they are different for different tasks. So to use your analogy, the more expensive remote can be used but it wasn't bought for use with the black plane. It'll give more control to the black plane but it still won't be the best ever until it learns what the muscle strength is etc. then it will be just as great.
The following is multiple choice question (with options) to answer.
The difference between skills and talents is that talents are innate and skills are | [
"extrinsic",
"Earth",
"armadillos",
"planets"
] | A | skills are learned characteristics |
OpenBookQA | OpenBookQA-3529 | electromagnetism, geophysics, geomagnetism
Title: Why is modelling the Earth as having geomagnetic poles useful? I'm reading about geomagnetic poles and wondering what their signifcance is. It seems one (and perhaps the main) purpose of using this type of model is for understanding the aggregation of magnetic particles from outside of earth. I feel as though I'm missing a step as to why this model is used, surely the magnetic particles from space still experience the irregular magnetic field of earth?
My guesses from the reading I've done so far are that:
At a great distance, the magnetic particles do actually experience equivalent attraction as though the Earth had a bar magnet that gave it its geomagnetic poles.
Over some time period, and over a number of particles the force experienced by all particles averages to what would be experienced if the Earth had a bar magnet that gave it its geomagnetic poles.
The following is multiple choice question (with options) to answer.
Which profession likely relies most on the Earth's poles? | [
"a bus driver",
"a salesman",
"a mechanic",
"a seaman"
] | D | when the needle of a compass lines up with Earth 's magnetic poles , the needle points north |
OpenBookQA | OpenBookQA-3530 | planet, night-sky, uranus
Title: Why wasn't the planet Uranus recognized by ancient cultures? Mercury, Venus, Mars, Jupiter, and Saturn have been identified by ancient astronomers as they are visible with naked eye at night. The planet Uranus, despite being visible during very clear nights, wasn't recognized as such. Why? The source of light that is Uranus was observed as far back as 128 BC. However it was misidentified as star as late as the 1760's. Then it was observed by Herschel in 1781, who also misidentified it, but as a comet. He had a telescope he built himself which would have been an impressive instrument for the day. He contacted another astronomer, one Nevil Maskelyne, who first suggested it was not a comet, but a planet. Further analysis by other astronomers made this more certain. It was essentially the orbit (not very elliptical) which seems to have been the main reason for identifying it as a planet. That and the apparent lack of a tail.
It required advances in observational accuracy and mathematical analysis of the observations to work out the orbit to work out it was a planet. These things simply were not possible to the required accuracy (or theoretical understanding) until Herschel's time.
From comments and by way of comparison, Saturn was considered a planet in ancient times. It has a shorter orbital period and is a great deal brighter than Uranus. It's relatively easy to spot this bright object whose (apparent) motion can be noticed and is easily distinguished from stars (unlike Uranus). Saturn is the 8th brightest natural object in the night sky. Uranus is the 350th. All the objects considered planets in ancient time were easier to see and notice the apparent motion of compared to stars. Uranus was just beyond that "natural" threshold where this could be done without relatively advanced technologies and theory.
The following is multiple choice question (with options) to answer.
A cylinder with lenses can even make Uranus appear to be | [
"farther",
"closer",
"scaled down",
"smaller"
] | B | if an object is close then that object will appear large |
OpenBookQA | OpenBookQA-3531 | wasps
Title: Can wasps see under moonlight? It appears that the best time to attack a wasp nest is in the middle of the night. Their venom might terrorize us (my five-day old sting remains swollen and is starting to have red bumps in an area the size of a tennis ball), but at least our eyesight is superior. If we attack while they are asleep, or at least resting, we have our best chance of escaping unscathed—or so the online pundits claim.
The nest in question is at the edge between the wall and the roof protrusion. Because it is 8 feet off the ground rather than on the ground, it would appear to be a paper wasp nest. But because it is covered with paper and the individual cells are occluded, with the entrance at the bottom the only visible path leading inside, it may well be a yellow jacket nest.
Maybe it's futile to attack the nest in September. One might as well let them be. The nest will anyway be deserted in October when the temperature starts to freeze overnight. But it's never too early to prepare for next Spring.
I could choose a night when there is absolutely no light—not even moonlight—but then I myself would need to use a flashlight, providing them with the means of pursuing me. Or I could choose a full-moon, or near full-moon, night, and then I can see and they can, perhaps, not see.
Can wasps see under moonlight? No.... probably not... wasp cannot see at night... their scotopic vision{dim light vision} is not well develop so before sunset they return back to thier nest... so at night.. probably you can get them all together... rather then hunting for each indivisually...for reference https://sciencing.com/how-to-identify-wasps-bees-13406632.html hope it helps..
The following is multiple choice question (with options) to answer.
Nocturnal predators hunt during when? | [
"sunrise",
"daylight",
"sleepy time",
"summer"
] | C | nocturnal predators hunt during the night |
OpenBookQA | OpenBookQA-3532 | thermodynamics, water, electrolysis
Title: Do water hybrid cars really exist? I have heard a few claims about water-fueled cars. Being a student of Engineering I totally understand that water-fueled cars (using electrolysis to generate Hydrogen) are nothing more than a hoax, unless you are giving electricity from an outer source.
However, I have heard quite knowledgeable people that water hybrid cars are quite a reality and you can save up to 60% on your fuel costs using some kind of kits. I have difficulty agreeing with this claim as well. I think inclusion of another step (hydrolysis) in the energy cycle of car power system will only make it less efficient. Reason being you can achieve at most as much energy from making a bond (burning Hydrogen) as much you spent on breaking it (Electrolysis).
Can someone please help me understand if I am missing some point? Or I am correct? The idea of splitting water using electrolysis and pumping it into an engine's air intake has been around for a long time. The idea is that it's supposed to increase the efficiency of burning gasoline. However, even assuming that this is true (there are many reasons why it may not be—modern gas engines are in the range of 95–98% efficient at combustion), electrolysis is very inefficient, so I'm quite dubious of any potential gains.
Hunting around on the internet, it's obvious that a lot of people seem to think this works (and that people who say it doesn't are oil company shills or some such), but I wasn't able to find any compelling evidence to support it. How this kind of system interacts with a modern computer controlled engine may perhaps even make efficiency worse. There doesn't seem to be much academic research into it, though a Google Scholar search brings up a lot of kooky patents. This kind of thing is pretty difficult to test well—tests need to be performed under very well controlled conditions to get accurate results and is thus always subject to confirmation bias and the like.
The following is multiple choice question (with options) to answer.
Sedans being powered by _______ is an example of an alternative fuel source | [
"maize",
"refuse",
"bees",
"soda cans"
] | A | An example of creating an alternative fuel is turning plant material into fuel |
OpenBookQA | OpenBookQA-3533 | visible-light, metals
Title: What does rainbow-colored-metal mean in the item that is supposed to be gold-plated silver? There is item (it is high ranking decoration of one country) that is supposed to be made from gold-plated silver with some (white) enamel. Here is the picture:
My question is - why there is this rainbow color, especially on the rays (especially on the upper-right rays) in the picture? What this rainbow means?
I have different ideas. E.g. that the gold has been removed by some fire and that left these marks. But some ordinary people said me, that temperature of gold removal or fire would be terminal for the silver which has very low melting point.
So, maybe this rainbow is the mark, that gold has been removed by some chemicals (king water?).
Or maybe (in the worst case) the rainbow color is the indication that this is base-metal fake that has been made by some copying process (I don't know, litography maybe?) that left such marks?
I am afraid that such rainbow marks can be indication of copying, of item being fake? the metal surface has a thin layer of oxide on it which causes interference fringes in color to appear. this same mechanism puts brightly colored fringes on the chrome-plating on motorcycle exhaust pipes.
The following is multiple choice question (with options) to answer.
A shoe seems gold and green at first, then at second glance looks blue and silver. This could be due to | [
"interrogation",
"comas",
"refractions",
"cellulite"
] | C | refraction causes something to look different |
OpenBookQA | OpenBookQA-3534 | magnetic-fields, ferromagnetism
Title: Technical Term for Material That is Only Magnetic Next to A Magnet I was wondering what the technical term is for some metal(like a refrigerator door) that is not magnetic on its own like neodymium but when there is a magnet in its vicinity, it attracts to the magnet. Neodymium has a polarity but these metals don't have one, they just stick to a magnet. Is it called ferromagnetism? As far as I know there is no single term to refer to a material that is attracted by magnetism but not a magnet. Rather, there are terms that describe a material's magnetic behaviour regardless of its magnetized state.
There are a few versions. Ferromagnetic, paramagnetic, and diamagnetic.
Ferromagnetic is like iron it will be attracted to other magnets, but can also be magnetized and turned into a permanent magnet.
Paramagnetic and diamagnetic materials can't be turned into permanent magnets. The difference might be considered nitty gritty and I'm not qualified to comment.
But it sounds like you're asking for a specific term for a material that is ferromagnetic, but not currently magnetized. I don't know of one.
The following is multiple choice question (with options) to answer.
something will attract magnets if that something contains a large amount of what kind of material? | [
"strong",
"water",
"liquid",
"rare-earth minerals"
] | D | if something contains a large amount of magnetic material then that something will attract magnets |
OpenBookQA | OpenBookQA-3535 | statistical-mechanics, atmospheric-science, density
A limnic eruption, also referred to as a lake overturn, is a rare type of natural disaster in which dissolved carbon dioxide (CO2) suddenly erupts from deep lake waters, forming a gas cloud that can suffocate wildlife, livestock and humans. Such an eruption may also cause tsunamis in the lake as the rising CO2 displaces water. Scientists believe earthquakes, volcanic activity, or explosions can be a trigger for such phenomenon. Lakes in which such activity occurs may be known as limnically active lakes or exploding lakes.
Picture 1: one of a number of cattle killed by a limnic eruption at Lake Nyos, Cameroon.
We can occasionally prevent the buildup of carbon dioxide by degassing the body of water.
Picture 2: a siphon used by French scientists to de-gas Lake Nyos. The carbon dioxide emerges from its deposits and bubbles into the water, floating to the top.
The following is multiple choice question (with options) to answer.
Stepping in a lake causes | [
"tsunamis",
"ripples",
"typhoons",
"earthquakes"
] | B | dropping an object into water causes vibrations in the water |
OpenBookQA | OpenBookQA-3536 | bacteriology, ph, gut-bacteria
Any one of these is enough to have a bactericidal or bacteriostatic effect! This is also why cells that do live in slightly alkaline or acidic environments have to specialize, and they have narrow windows of pH that they can survive under, because they have to compensate so much to counteract the protonation or lack-thereof in their environments.
The following is multiple choice question (with options) to answer.
If a person has bacteria in a certain part of their insides, it can help by | [
"growing them another arm",
"making them much fatter",
"giving them a fever",
"pulling minerals from nutriment"
] | D | bacteria can help digest food in humans |
OpenBookQA | OpenBookQA-3537 | 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 amphibian is cold-blooded |
OpenBookQA | OpenBookQA-3538 | particle-physics
Title: Explanation for self-rupture glass is needed I witnessed a phenomenon that I couldn't conclude its cause. Please bear with me for the length of the recall, for I merely want to include any details that might help us to investigate. I had a cooking glass lid sat on a wooden shelf that is away from the stove and oven and other heating objects. The shelf is nailed on the wall and is situated just above my eye level, and a counter top is also on the same side of the wall where the shelf is installed.
Now here comes the surprise. In a winter afternoon 2011, my room had almost the same temperature as an autumn morning, and while I was cutting my lettuce on that counter top which I pointed out in above passage, a pounding sound, as if a heavy car door slam or a tree trump falling on top of the roof, knocked its introduction from the shelf that was just above my eye level. First, I thought I may had knocked something around me off(which I didn't believe that for there wasn't anything around me to knock off); then I thought it may be my neighbor next door dropping a heavy box; last, I suspected somewhere my roof top collapsed.
But it was my third suspicion directed me to meet that glass lid I mentioned above, and I found it had ruptured completely like glacier creaked BUT still having all broken pieces bounded without any pieces scattering toward random direction! Only the nob of the lid popped out partially. Before this happened, I hadn't used that lid for cooking for years, and I didn't removed it from any heating object nor there was something on top of the lid that day, and I believe what the lid had maybe just an invisible layer of dust.
I was glad my face hadn't been stung by any glass residues, but ponder what really happen to that glass lid and why it ruptured without collapsed. Below, I attached 2 pictures of the scene from that day. If you have any similar experience or know the theory behind it, may you please drop me an explanation to this incidence? Thank you in advance.
The following is multiple choice question (with options) to answer.
Which of these would you use in order to figure out why buildings may have collapsed? | [
"radio",
"clock",
"seismometer",
"pendulum"
] | C | a seismometer is used to measure the strength or magnitude of an earthquake |
OpenBookQA | OpenBookQA-3539 | eyes, vision, feline
Fig. 3. Lens transmission spectra of various species. Source: Douglas & Jeffery, 2014
References
- Douglas & Jeffery, Proc R Soc B (2014); 281: 20132995
- Griswold & Stark, Vis Res (1992); 32(9): 1739-43
The following is multiple choice question (with options) to answer.
scientists make observations and cats | [
"regurgitate their cleanings",
"never sleep",
"fly",
"cook spaghetti"
] | A | scientists make observations |
OpenBookQA | OpenBookQA-3540 | meteorology, climate-change, gas, pollution
Title: Regarding various types of atmospheric pollution Does all the car pollution (from about 150 million cars at least in the U.S. and a lot more in all of North America and the rest of the world) all the smoke-stack pollution of various factories and all the Airline pollution running day after day have a deleterious and damaging effect on the general atmosphere and, over time, the climate?
Given all the observed pollution that China has caused itself and some of the resulting weird weather events there this certainly seems to be evidence of the damaging effects of car and factory pollution. Has anyone calculated how much exhaust from cars is produced in one day on average in a 'moderate' sized city?
Of course it seems with all the increased oil production in the U.S. and elsewhere we, human beings are going to keep are love-affair with gas-powered cars for the next 200 or 300 years. That is if we don't use up all the oil and gas in the ground before then. As a USA resident, the EPA is the best place to start when wondering about the emissions inventory of atmospheric pollutants or pollutant precursors that affect the National Ambient Air Quality Standards (e.g. Particulate Matter, Carbon Monoxide, Sulfur Dioxide, Lead, Nitrogen Oxides, Volatile Organic Compounds). The EPA compiles a comprehensive emissions inventory of all criteria pollutants at the county level which is available in the National Emissions Inventory (compiled once every 3 years). You can see the summary of your county at http://www.epa.gov/air/emissions/where.htm. As for the effects of atmospheric pollution, it is important to consider the lifetime of said pollutants in the atmosphere in order to put their environmental impacts into perspective. For instance, the air pollutants covered by the National Ambient Air Quality Standards have immediate health effects when high concentrations are breathed in regularly. Both animals and plants are adversely affected by these irritating and sometimes toxic chemicals, but these pollutants are also reactive and do not last long in the atmosphere unless they are constantly being replenished (e.g. daily traffic). Air quality also impacts critical nitrogen loads on ecosystems and possible production of acid rain.
The following is multiple choice question (with options) to answer.
pollution is when humans pollute the environment with | [
"gross stuff",
"water",
"food",
"air"
] | A | pollution is when humans pollute the environment with pollutants |
OpenBookQA | OpenBookQA-3541 | brain
Title: Does "mind" has any physical reality in biology? Or is it just an assumptive concept? Biologically, Brain controls our thinking, ideas, decisions everything along with controlling each body parts. My question is, is there anything real as "mind "? If it's controlled by brain then how does brain controls the mind? The mind is an abstraction which arises from physical and chemical processes within the brain. For a crude analogy, think of the brain as an incredibly complex, self-modifying, multithreaded program. The mind would then be the abstraction arising from the behavior of the program as it runs. Consciousness would be the abstraction arising from the behavior of one particular thread in the program: a thread which has access to a limited buffer of its own (that thread's) behavior, and control over limited input and output from the body. All of the other (unconscious) threads may affect the conscious thread, but the conscious thread has very limited access to information about the behavior of the other threads.
Since the conscious part of the mind has access to information about its own behavior, there is actually some recursive looping going on when it comes to thinking and feeling. The feeling that this goes in circles somehow (which you seem to be expressing) is a common intuition, and it's almost certainly a correct one. But the manner in which this occurs is not well-understood, and it's definitely not well-understood within biology at the macro level because the brain is unbelievably complex and plastic. We really don't have a clue how to begin modeling the brain's processes. This is one reason artificial intelligence is still extremely crude today (despite what Elon Musk and Bill Gates may try to say).
If you want to read a scientifically-inspired theory of from whence consciousness comes, and of how it arises from the brain, I would recommend the book Godel, Escher, Bach by Douglas Hofstadter. Douglas does a good job of combining computational theory with biology, music, and art to illustrate a theory of consciousness the reader can grasp even if you don't have a strong background in any of those subjects.
The following is multiple choice question (with options) to answer.
An animals brain controls what? | [
"said organism",
"others",
"plants",
"fauna"
] | A | an animal 's brain controls that animal |
OpenBookQA | OpenBookQA-3542 | organic-chemistry, physical-chemistry, biochemistry, alcohols
Title: Storage of Urine Not all may be favorable to this project, but I will explain what I am trying to do. I work at home, and instead of walking a moderate distance to the bathroom and loosing my focus, I've been, at times, peeing in a 3 Quart Poland Springs water bottle. If you take offense at this, please do not continue reading except to be helpful in the scientific goal. I know this subject won't suit many types of people, so just ignore it if that is your case.
I noticed first of all that urine is not at all as sterile as people say that it is. The rate of growth of bacteria is relatively slow, but as a precaution, I found the need to use additional measures to prevent the growth of bacteria. I settled on the following method: I have two bottles and I add to each bottle about enough salt as can be soluble in the urine and sometimes maybe a little more. The one bottle then fills up throughout the day and is emptied, washed, and refilled with salt. The salt helps to kill the bacteria which would be lingering in the empty bottle. The next day, the bottle stays empty and the other is used.
I would add that I discovered that the bacteria (without the salt) does not usually grow unless the bottle is left with urine for two days. After this, however, that same bottle (without the salt) would retain the bacteria and immediately grow, if used again.
This system works relatively well, so long as it is done every day. It will even withstand 2 days with only moderate growth. (If I should leave it by mistake for longer it can get ugly). Nevertheless, I am still looking to improve upon this. One reason is that, if I drink less water or relieve myself normally, the bottle does not fill in one day. I am looking for someone with knowledge of chemistry to help me find a substance that can be added to this solution which fits a number of common sense criteria. I will also add a list of the substances that I have tried or already considered.
Necessary qualities
The following is multiple choice question (with options) to answer.
Organisms can be preserved in | [
"Sandstone",
"Water pipes",
"Cars.",
"Trees"
] | A | organisms can be preserved in sedimentary rock |
OpenBookQA | OpenBookQA-3543 | 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.
Polar bears live in | [
"deserts",
"snowy areas",
"apartments",
"hot areas"
] | B | polar bears live in cold environments |
OpenBookQA | OpenBookQA-3544 | evolution, human-evolution
Title: Can there be significant new changes in physical features of Humans due to evolution in 10000 years of span? Humans migrated from Africa about 60000 years. And in these years humans physical features undergone significantly in terms of skin color, hair, eye color and facial features.
So, with this we can say that given 10000 years of span we can see a significant noticeable new changes in physical features of humans? like some humans with new skin color (apart from today's white, black and brown), new color eye balls, big heads etc.? Yes & perhaps (or probably?) no, depending on what you define as significant changes.
Less than 10,000 years ago everyone in the british isles & the rest of europe were dark skinned so the answer if (unlike me) you consider the change in skin color a significant change is obviously a resounding yes.
Here's what English people looked like 10,000 years ago
Darker skinned than you were expecting perhaps.
If as suggested in this article white skin arrived in Europe around 5,000 years ago that only leaves 2,000 years before early Greek & Roman art we have available which shows it as ubiquitous, so it perhaps took only 2,000 years or so (maybe less) to become dominant in europe, that's fast.
Using 20 years as the measure of a generation that's only 100 generations, so, very fast.
Timeline of human prehistory
The first reconstruction in the link below is a reconstruction of a Neanderthal woman found in a cave in Gibraltar. She died at least 30,000 years ago.
Here she is, the skin tone may not be accurate but we do know from gene's recovered from Neanderthal remains that they were relatively light skinned.
Personally I don't consider her appearance to be significantly different from modern humans.
29 Reconstructed Faces Of Ancient People
So my answer based on what I consider significant changes would be no.
But for you or others the answer may well be yes.
And of course a mutation for a new eye colour could appear at any time in one individual & spread like wildfire practically overnight just because we think it's unusual & 'cool' (aka sexual selection) so if eye color ticks your boxes it's a very definite yes.
The following is multiple choice question (with options) to answer.
Which human is more likely to be free of scars | [
"a pro athlete",
"an active kid",
"an old man",
"an unborn boy"
] | D | a scar is an acquired characteristic |
OpenBookQA | OpenBookQA-3545 | botany, color
Hypothesis 1
It should be remembered that chlorophyll is far from being the only pigment found in leaves. For example, carotenoids - which give yellow and reddish colors - are present in plant leaves. There are many carotenoids (according to Wikipedia there are over 1100 known, but that number will continue to grow). The biological roles of these carotenoids are also varied. In the course of the question, we may be interested, for example, in the photoprotective role of carotenoids. They are involved in the deactivation of reactive oxygen species (ROS). ROS can be formed during photosynthesis and can potentially be harmful to cells. Therefore, in conditions of excess solar radiation, plants can increase concentrations of carotenoids to prevent oxidative stress. It has already been pointed out to you in the comments that younger leaves look yellow - this is a common occurrence. The leaf is a very expensive organ, in the sense that the plant invests a lot of plastic substances in its development. So it makes sense that young, growing leaves get extra protection. That is, a young leaf that has not yet formed all the necessary structures (thick enough cuticle, efficient conductive system, etc.) is less efficient in terms of photosynthesis and therefore more susceptible to negative processes of photodamage. Increased concentrations of carotenoids, among other things, can reduce such risks. If you add to this the small thickness, it is understandable why young leaves often look more yellow.
Hypothesis 2
I have already said that leaves are expensive organs. They have a high protein content, which is very valuable to the plant. If a leaf is damaged or aged, there is a threat of irreversible loss of protein, which would be a great waste. Therefore, in such cases, plants trigger complex processes of removing valuable substances from the leaves. In particular, chlorophyll begins to break down, and the decomposition products are transported to the more durable parts of the plant. This is the reason why leaves change color in the fall, before defoliation. When the concentration of chlorophyll decreases, other pigments, such as carotenoids, increasingly affect leaf color. That's why damaged and old leaves often turn yellowish.
Although, I doubt that in the case of your plant, this process is often the cause for yellow leaves.
Hypothesis 3
The following is multiple choice question (with options) to answer.
Roses utilize chlorophyll to | [
"turn themselves blue and pink",
"take in sun rays",
"turn oxygen into CO2",
"take in dust particles from the air"
] | B | chlorophyll is used for absorbing light energy by plants |
OpenBookQA | OpenBookQA-3546 | 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.
As watering holes dry up more animals will | [
"die",
"move in",
"join together",
"dig wells"
] | A | as available water in an environment decreases , the amount of available food in that environment will decrease |
OpenBookQA | OpenBookQA-3547 | inorganic-chemistry, acid-base, everyday-chemistry
$$\ce{H2O + CO2(aq) <=> H2CO3}$$
and the protolysis of true $\ce{H2CO3}$
$$\ce{H2CO3 <=> H+ + HCO3-}$$
For a weak acid
$$\begin{align}
\log[\ce{H+}]&\approx\frac12\left(\log K_\mathrm a+\log[\ce{H2CO3^*}]\right)\\
&=\frac12\left(-6.3-5.0\right)\\
&=-5.65\\
\mathrm{pH}&=5.65
\end{align}$$
Thus, pure rain in equilibrium with the atmosphere has about $\mathrm{pH}=5.65$. Any acid rain with lower $\mathrm{pH}$ would be caused by additional acids.
The following is multiple choice question (with options) to answer.
Rain also occurs in other places like | [
"My emotions",
"My mind",
"planetoids",
"In a bath"
] | C | as the amount of rain increases in an environment , available sunlight will decrease in that environment |
OpenBookQA | OpenBookQA-3548 | species-identification, botany, ecology
Title: Algae or Lichen identification. Coastal BC, Canada I have tried all books and internet resources I know of, but I still have no idea what this might be — a lichen or something else.
At first glimpse, I thought it was something man-made and unnatural, but then I looked closer and saw how it appears to be attached and growing. It grows on exposed rocks well above the high tide. The photo is taken in late March, on northern Vancouver Island. It's loosely attached to the rock.
It was somewhat abundant around the general area (within of a few km), but I haven't seen it elsewhere - although I'm not from BC so there might be a lot of this around.
The water droplet in the lower right corner give a rough sense of scale.
Edit:
Adding another photo in which I just noticed a streak of white, which I included in original resolution. I want to propose you expand your search to a broader taxonomic scope. Specifically, I think you might be looking at a species of "red" green algae (family: Trentepohliaceae).
From Nelson et al. (2011):
All Trentepohliaceae have filamentous growth forms and often contain large amounts of carotenoid pigments (ß-carotene and hematochrome), causing the algae to appear yellow orange in color (Thompson and Wujek 1997, Lo´pez-Bautista et al. 2002).
The Trentepohliaceae contains five genera: (Trentepohlia, Printzina, Phycopeltis, Cephaleuros and Stomatochroon) and 70+ species worldwide.
For example, the following algae (picture from England) looks fairly similar to your specimen:
Trentepohlia aurea
Source: David Fenwick
If your specimen is a species in this family of algae, it is most likely in the Trentepohlia genus (or possibly Printzina genus).
Trentepohlia is a genus of filamentous chlorophyte green algae in the family Trentepohliaceae.
Typically orange or yellow in color.
Live on tree trunks and wet rocks or symbiotically in lichens.
Here's a picture of a free-living Trentepohlia species from coastal Oregon, USA:
Source: Richard C. Hoyer (2015)
The following is multiple choice question (with options) to answer.
Succulents will die during winter months in canada without the aide of a | [
"glass structure",
"firehouse",
"smokehouse",
"bonfire"
] | A | a greenhouse is used to protect plants by keeping them warm |
OpenBookQA | OpenBookQA-3549 | evaporation, humidity
Title: Confusion understanding relative humidity levels I have difficulty in understanding how can the relative humidity of a mixture of air and water can be 100%. I understand that places like where i live have high relative humidity, so the place is more humid (rain forest) than deserts, for exemple. But an evaporator, in an air conditioning system, removes the water from the air passing in and elevates the relative humidity of it. So why does a mixture containing, for example, 50% of relat. humidity can lose water mass from it and have a highier relat. humidity level?
Thanks :) For a given temperature and pressure, there is a maximum amount of water vapor which can exist in gaseous form. Any greater concentration will cause some of the vapor to condense. Measuring the absolute amount of vapor in the air produces absolute humidity, which is not expressed in per cent.
Relative humidity, however, is the amount of water vapor relative to the theoretical maximum at that temperature and pressure - that's why it's called relative. It is defined as the ratio of the two concentrations expressed as a percentage. So if the air contains the maximum amount of water vapor that it can hold without any condensing, the relative humidity is, by definition, 100%.
The following is multiple choice question (with options) to answer.
moist means high in what? | [
"wetness",
"warmth",
"depth",
"temperature"
] | A | moist means high in moisture |
OpenBookQA | OpenBookQA-3550 | electric-circuits, charge, potential-energy, batteries, chemical-potential
Here's a way to imagine the process: a battery is like a spring-driven "wind up" water pump. Send water backwards through this pump, and you wind up the internal spring. Then, provide a pathway between the inlet and the outlet of the pump, and the spring-motor will pump the water in a circle. But now think for a moment: the water is the charge, yet our wind-up pump does not store water! When we "charge" our wind-up pump, we send the charge (water) through the pump, and this stores energy by winding up the spring. Same with a battery: to "charge" a battery, we send electrical charges through the battery and back out again. This causes the chemicals on the battery plates to store energy, just like winding up the spring in our spring-powered water pump. See how "charging" and "charges" can create a horrible mess of misunderstandings? When this mess gets into the K-12 textbooks, and educators start teaching it to kids, the kids end up believing that Electricity is far too complicated for them to understand. Yet the fault does not lie with the students!!!!
The following is multiple choice question (with options) to answer.
the energy of the ocean can be harnessed to charge a battery that eventually powers a | [
"cupcake",
"rock",
"nosehair trimmer",
"tree"
] | C | tidal energy can be used to produce electricity |
OpenBookQA | OpenBookQA-3551 | forces, mass, acceleration, speed
Title: Does an Increase of Force affect the Speed of an object if the acceleration stays constant? If I had a mass of $100\:\rm{kg}$ accelerating due to gravity, using $F=ma$:
$F = 100\:\rm{kg} \times 9.8\:\rm{m/s^2}$
$F = 980 \:\rm N$...
If I increased the mass to 200kg, the force would be 1960 N:
$F = 200\:\rm{kg} \times 9.8\:\rm{m/s^2}$
$F = 1960 \:\rm{N}$
Now, finally getting to my question: Does this increase in force (which is supposed to be a push/pull) mean that the object would fall faster when it weighs more? No, the heavier object does not fall faster. Instead, they heavy and light object fall at the same acceleration (and hence the same speed if they are both simply dropped). This is an example of the equivalence principle.
The more massive object has more gravitational force on it, but it also has more inertia. Specifically, because the object is twice as massive, it has twice the inertial mass.
The force on it is doubled, so the acceleration stays the same.
If we look at
$$F = ma$$
we see that when $F$ and $m$ are both multiplied by 2, $a$ stays the same.
Check these questions for more:
Free falling of object with no air resistance
Why is heavier object more reluctant to get falling down?
Projectile motion without air resistance
The following is multiple choice question (with options) to answer.
Force causes the speed of an object to do what? | [
"lessen",
"uptick",
"decrease",
"lower"
] | B | force causes the speed of an object to increase |
OpenBookQA | OpenBookQA-3552 | ## Example 5
Again, Delaware, with an initial divisor of $$21,900.82927$$:
$$\begin{array}{lrrc} \text { County } & \text { Population } & \text{ Quota } & \text{ Initial } \\ \hline \text { Kent } & 166,310 & 7.4111 & 7 \\ \text { New Castle } & 538,479 & 24.5872 & 25 \\ \text { Sussex } & 197,145 & 9.0017 & 9 \\ \textbf{ Total } & \bf{ 897,934 } & & \bf{ 41 }\end{array}$$
Solution
This gives the required total, so we’re done.
## Example 6
Again, Rhode Island, with an initial divisor of $$14,034.22667$$:
$$\begin{array}{lrrc} \text { County } & \text { Population } & \text{ Quota } & \text{ Initial } \\ \hline \text { Bristol } & 49,875 & 3.5538 & 4 \\ \text { Kent } & 166,158 & 11.8395 & 12 \\ \text { Newport } & 82,888 & 5.9061 & 6 \\ \text { Providence } & 626,667 & 44.6528 & 45 \\ \text { Washington } & 126,979 & 9.0478 & 9\\ \textbf{ Total } & \bf{ 1,052,567 } & & \bf{ 76 }\end{array}$$
Solution
This is too many, so we need to increase the divisor. Let’s try $$14,100$$:
The following is multiple choice question (with options) to answer.
To encourage population growth in an area | [
"dry out any water sources",
"add another water feature",
"plant more toxic flowers",
"kill off any prey"
] | B | as the available water in an environment increases , the populations of organisms in that environment will increase |
OpenBookQA | OpenBookQA-3553 | species-identification, zoology, marine-biology, ichthyology, bone
Title: Identification of a strange skull My father is a fisherman in the Baltic sea, and he has found this very strange skull. I would like to know to which animal it belonged. Can someone help identify it? Looks like this is a neurocranium of a tuna or a similar species (dorsal view on this site).
I've also found a very similar picture of Atlantic blue tuna from USA, which seems to support that this is indeed a neurocranium.(source of the picture).
Thank you all for your help!
The following is multiple choice question (with options) to answer.
A tuna would prefer to consume | [
"An Apple",
"beef",
"Nemo",
"dogs"
] | C | tuna eat fish |
OpenBookQA | OpenBookQA-3554 | The area under the green curve can be found using the trapezium rule, 0.5(a+b)h. Doing this for the first trapezium we get 0.5(0+0.063)(0.2) = 0.0063. The second trapezium is 0.5(0.063+0.162)(0.2) and so on. Adding these areas all together we get a total trapezium area of 0.3074. Therefore we get the area between the two curves as 0.5 – 0.3074 ≈ 0.1926
The Gini coefficient is then given by 0.1926/0.5 = 0.3852.
The actual World Bank calculation for Thailand’s Gini coefficient in 2002 was 0.42 – so we have slightly underestimated the inequality in Thailand. We would get a more accurate estimate by taking more data points, or by fitting a curve through our plotted points and then integrating. Nevertheless this is a good demonstration of how the method works.
In this graph (from here) we can see a similar plot of wealth distribution – here we have quintiles on the x axis (1st quintile is the bottom 20% etc). This time we can compare Hungary – which shows a high level of equality (the bottom 80% of the population own 62.5% of the wealth) and Namibia – which shows a high level of inequality (the bottom 80% of the population own just 21.3% of the wealth).
How unequal is the world?
We can apply the same method to measure world inequality. One way to do this is to calculate the per capita income of all the countries in the world and then to work out the share of the total global per capita income the (say) bottom 20% of the countries have. This information is represented in the graph above (from here). It shows that there was rising inequality (i.e the richer countries were outperforming the poorer countries) in the 2 decades prior to the end of the century, but that there has been a small decline in inequality since then.
If you want to do some more research on the Gini coefficient you can use the following resources:
The intmaths site article on this topic – which goes into more detail and examples of how to calculate the Gini coefficient
The ConferenceBoard site which contains a detailed look at world inequality
The following is multiple choice question (with options) to answer.
If a globe has a range of populace, it likely also has | [
"old babies",
"varied homes",
"poisoned blood",
"teal rabbits"
] | B | the Earth contains many ecosystems |
OpenBookQA | OpenBookQA-3555 | c#, design-patterns, beginner, classes
//Happiness relates to playing with the pet
public PetMood Mood { get; protected set; }
//Pet hunger level
public HungerLevel Hunger { get; protected set; }
//Has the pet been vaccinated
public bool IsVaccinated { get; private set; }
//The pet class constructor
public void GivePetShot()
{
IsVaccinated = true;
}
public virtual PetMood PlayWithPet()
{
var message = GetPlayWithPetMessage();
if ( (int)this.Mood < 4 )
{
Console.WriteLine( message );
return this.Mood += 1;
}
Console.WriteLine( message );
return this.Mood;
}
public abstract string GetPlayWithPetMessage();
public virtual PetMood PunishPet()
{
string message = GetPunishPetMessage();
if ( (int) this.Mood > 0 )
{
Console.WriteLine( message );
return this.Mood -= 1;
}
Console.WriteLine( message );
return this.Mood;
}
public abstract string GetPunishPetMessage();
public virtual HungerLevel FeedPet()
{
if ( (int)this.Hunger < 3 )
{
Console.WriteLine( GetFeedPetSuccessMessage() );
this.Hunger += 1;
return this.Hunger;
}
Console.WriteLine( GetFeedPetFailedMessage() );
return this.Hunger;
}
public abstract string GetFeedPetSuccessMessage();
public abstract string GetFeedPetFailedMessage();
public HungerLevel StarvePet()
{
string message = GetStarvePetMessage();
if ( (int)this.Hunger > 0 )
{
Console.WriteLine( message );
this.Hunger -= 1;
return this.Hunger;
}
Console.WriteLine( message );
return this.Hunger;
}
public abstract string GetStarvePetMessage();
public void UpdatePet( HungerLevel hunger )
{
if ( hunger != Hunger )
{
Hunger = hunger;
}
}
public void UpdatePet( PetMood mood )
{
if ( mood != Mood )
{
Mood = mood;
}
}
The following is multiple choice question (with options) to answer.
A puppy feels hunger and moves straight to its female parent's nipple. This behavior is | [
"learned",
"instinctive",
"reactive",
"predatory"
] | B | an animal knows how to do instinctive behaviors when it is born |
OpenBookQA | OpenBookQA-3556 | botany, entomology
Title: What is this small white insect on my plants? Environment
I have a large amount of plants in an old industrial loft apartment.
I live in Rochester, New York.
I ship plants in from across the US, often exotic ones.
Observations
A few months ago, I noticed that two of my Sarracenia plants in my carnivorous plant bog were not growing anymore. Upon cutting them out as to not disrupt the live sphagnum moss grow medium, I noted that one of the insects in question had burrowed its way down into the core of the plant. I assume this to be the cause of the growing issue.
Today I noticed that one of my grape plants and Colocasia plants were covered in these bugs at different stages of growth. They range from white specs to ~3mm with the tail thing.
These insects appear sedentary. I have never seen one move, except when I cut the one out of the center of the plant.
Here is a picture of the bug, which was difficult to get due to the size.
Research
I looked through a variety of different "common insect" sites as well as some insect identification sites but I was unable to find anything remotely similar.
I have only elementary knowledge of insects. Any pointers in the right direction would be appreciated. Mealybug; don't know much about them.
The following is multiple choice question (with options) to answer.
Wax is on some plant leaves for what reason? | [
"stay moist for warm weather",
"keep water available for predators",
"keep the hydration inside",
"creation of toxins in the cells"
] | C | usually plants store the food they produce for future use |
OpenBookQA | OpenBookQA-3557 | thermodynamics
= T_1( C_v + \frac{P_{ext}R}{P_1})$$ and thus we have our desired result as, $$T_2=[\frac{C_v + (\frac{P_{ext}}{P_1})R}{C_v + (\frac{P_{ext}}{P_2})R}]T_1$$
The following is multiple choice question (with options) to answer.
To pass on heat one might | [
"eat food",
"hold hands",
"time travel",
"fart"
] | B | heat can change the state of matter |
OpenBookQA | OpenBookQA-3558 | friction
as expected.
So the blocks will slide over one another if
$\dfrac {F_1M + F_2m}{M+m} > Fr_{max} = \mu mg$
If $F_2 > F_1$ then a similar calculation gives the same condition.
The following is multiple choice question (with options) to answer.
Rocks collide with each other when moved by | [
"dead valley girls",
"radio waves",
"glaciers",
"feathers"
] | C | contact between rocks over long periods of time causes rocks to smooth |
OpenBookQA | OpenBookQA-3559 | motor, power
Title: Additional Power to DC Motor via Second Power Source How can I provide more power to a DC motor that is in series behind a receiver circuit hacked out of a cheap RC car without burning up the receiver board? The board runs off two AAs at about 3V. I'm replacing the stock motor with a slightly larger one (12V, taken from a printer) and remounting it on a chassis for a homebrew robotics project... just messing around to learn more. I imagine I could go safely to 4.5V or even 6V with the receiver but I don't want to go much higher since half the stuff is epoxied and I can't really tell what's in there.
What I'd like to be able to do is add an additional two AA batteries behind the receiver to run the receiver system at 6V but add another two 3V 123A batteries to have the motor at 12V with the ability to run with the higher current draw due to the heavier load the motor will handle on its fancy new chassis... but without pulling that current through the receiver circuit.
My first thought is to simply connect my 123As negative to the motor and positive to a common ground... but I'm really not sure and I want to be careful to not damage the circuit or batteries. My next thought is to simply build a single power supply out of my 123As and use a current divider but I've only read about them and never actually tried so.
I've been doing some of those kiddie "electronic playgrounds," a few books and probably cost Google an extra few bucks in energy costs and I'm still kinda at a loss. It is safest to isolate the power supply for the motors from the electronics.
Normally, there is a single top-level power supply, eg. at 12V. This can supply the motors and other actuators directly. Because electronics normally run at 5V or 3V, a voltage regulator is often used to decrease the voltage (it taps into the 12V supply, and outputs a regulated 5V for the electronics). This is good, because the current motors draw can change quickly and may sometimes affect the power supply. In this case, if the voltage regulator is insufficient, capacitors may be added across the 12V supply, but this is not often required.
The following is multiple choice question (with options) to answer.
which one of these can be used to power up a system? | [
"a handful of sand",
"a liter of water",
"a bowl of water",
"a tin of gasoline"
] | D | oil is a source of energy |
OpenBookQA | OpenBookQA-3560 | earth, the-sun
Title: Latest sunrise/earliest sunset out of phase with solstice? Everybody knows that the shortest and longest days of the year occur on the solstices. However, examination of sunrise/sunset tables shows that the maxima and minima of sunrise/sunset times are offset from the solstices by about 10 days.
According to timeanddate.com for my location (Portland, OR), for the winter solstice, the earliest sunset is about December 10 (16:27), and the latest sunrise is around January 1 (07:51).
This is counterintuitive... what's the explanation? The point here is that sunrise and sunset does not only move towards or away from noon, but noon itself moves around 12:00. There is a difference between "civil time" (the one counted by wall clocks) and "solar time" (the one marked by sun clocks). This difference is called the "Equation of Time" and its geometrical shape is called the Analema.
So in order to have the earliest sunset you need a combination of both a short day and a noon moved before 12:00. Same reasoning for latest sunrise.
You can see more about the Equation of Time on Wikipedia: http://en.wikipedia.org/wiki/Equation_of_time
The following is multiple choice question (with options) to answer.
the solstice with the longest day happens in the month after | [
"november",
"may",
"january",
"march"
] | B | the summer solstice is on June 21st in the northern hemisphere |
OpenBookQA | OpenBookQA-3561 | 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.
animals are unable to stay in good health without enough | [
"sustenance",
"video games",
"socks",
"doors"
] | A | an animal requires enough nutrients to maintain good health |
OpenBookQA | OpenBookQA-3562 | mountains, rainfall
Title: Could a waterfall lashing onto a road lead to a landslide? Here is a video of a waterfall lashing on to a mountain road, with vehicles driving under it.
https://youtu.be/cHaguj--YBc
There appears to be a big hole carved out right next to the road, possibly by the force of the waterfall.
Is this a ticking time bomb for a landslide? Potentially, a landslide could occur. Whether it would be a minor slip or a major fall depends on the geological conditions at the site, the force of the water and the duration that the site is impacted by the water.
In the video in question, the rock face above the road appears competent, but there are not guarantees. The main issue would be is the water undermining the road which could cause a slip and the road to slide.
The more loose the geological material is, the easier it is to dislodge it. Once one item moves a chain of events can occur where additional items are dislodged and a slide occurs.
In addition to high pressure water dislodging material, water acts as a lubricant, making it easier for rocks and regolith to be dislodged.
To minimise the potential for a slide to occur in such a situation, the surface of the road would need to be sealed very well and a very good drainage system installed that would move the water away from the road and the slope below the road
The following is multiple choice question (with options) to answer.
What might damage a hard walkway that runs alongside a street? | [
"a child walking",
"snow",
"a tree nearby",
"a running dog"
] | C | if a tree is located near a sidewalk then the roots of that tree might crack the sidewalk |
OpenBookQA | OpenBookQA-3563 | electromagnetism, magnetic-fields, electric-fields, electromagnetic-induction
Consider as an example : Sinusoidal field applied to the coil. (Suppose the field to be in $z$-direction and coil to be in $xy$-plane.
$$\vec{B}=B_0\sin(\omega t)\hat{k}$$
As an exercise find $\vec{E}$ using the symmetry of the system and
$$\nabla \times \vec{E}=-\partial_t\vec{B}$$
(Otherwise, See Example (Sinuaoidal B field) Page 358 Chapter 7 In Electricity and Magnetism Purcell)
$$\vec{E}=-|E_0|\cos(\omega t)\hat{\varphi}$$
$$\rightarrow \mathcal{\vec{S}}= -|E_0|B_0\cos(\omega t)\sin(\omega t)\hat{r}$$
More specifically, see the direction of the poynthing vector which is inward and thus showing the there is a flow of energy into the system. Also as an exercise find
$$\partial_t\mathcal{U}=??\rightarrow \text{Verify}\ =-\nabla \mathcal{\vec{S}}$$
Which confirms the energy conservation.
The following is multiple choice question (with options) to answer.
An example of an electromagnet is | [
"running",
"recorders",
"grass",
"rock climbing"
] | B | electromagnets can be powered by electricity |
OpenBookQA | OpenBookQA-3564 | 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.
which of these conditions might lead to the inability to move one's bones? | [
"the absence of blood platelets",
"an absence of vitamin C",
"muscular wasting might be present",
"a shortage of white blood cells"
] | C | muscles pull bones to move the bones |
OpenBookQA | OpenBookQA-3565 | behaviour
Title: What happens to silverfish when we throw them out the window? I'll find a silverfish from time to time in my flat. I don't mind them but usually I catch them and throw them off the balcony (second story) into the bushes and lawn below.
I was wondering, since they seem to live in the water conduits in the house, if they can survive outside or if they die/get killed instantly.
Thx for your help! Silverfish prefer high humidity and warmth. Ctenolepismacalvum (Ritter, 1910) was recently found in Japan at a temperature of 20-30°C and 50-60% RH. As long as there are pieces of bark, wet grass or other organic or human-made structures that retain humidity after each raining event, the likelihood that they will survive long enough to complete their cycle is high.
They could face dessiccation if they are not able to find a damp spot in time, depending on their tolerance to it. However, it was not possible for me to find information about their dessiccation tolerance.
The Zygentoma (silverfish order) have high tolerance to low humidity and most of the species inhabit dry and hot environments (it's just a few that like humidity), which again makes me think that those silverfish propelled out the window will survive.
The following is multiple choice question (with options) to answer.
coral lives in the | [
"wet depths",
"cupcakes",
"trees",
"sky"
] | A | coral lives in the ocean |
OpenBookQA | OpenBookQA-3566 | evolution, zoology, adaptation
One answer that came to mind is domestic animals - the horse and dog in prehistory, the cat in ancient Egypt, etc. That seems too obvious on one hand, and on the other hand may not really be an answer, as there seems to be no indication that pre-domestic animals were endangered by humans in any meaningful way. Are there animals that have significantly adapted themselves to surviving as wild animals in human-influenced environments? Note: This is an answer to the last line of your question.
A classical example of animals adapting to the influence of humans on their environment is the adaption of the Peppered Moth.
Here is a brief summary:
The peppered moth was originally a mostly unpigmented animal (<1800). During the industrial revolution in the southern parts of the UK a lot of coal was burned. This led to soot blackening the countryside. Soon afterwards, a fully pigmented variety was first observed. Only a hundred years later, in 1895, this pigmented variety almost completely displaced the unpigmented variety.
It has been shown that the pigmentation is under strong selective pressure as birds hunt these moths. Since birds rely on their visual system to detect their prey, the variety that blends in with its environment (=camouflage) has a selective advantage over the variety that stands out.
As pointed out by Tim in the comments, since the 1970s there has been a rapid reversal with unpigmented animals being more abundant. As far as I understand, it is accepted that this reversal is due to a decrease in human induced air pollution leading to less sooty barks on trees which makes the unpigmented variety harder to prey upon.
Addendum: genetic basis of adaption
In a beautiful recent study, the causal mutation for the pigmented, or melanic, variety was identified: A ~9kb transposon insertion in the first intron of the gene cortex. The authors calculate that this mutation happened in the year 1819, a few years after the industrial revolution was in full swing. The interpretation is that due to sooty tree bark this mutation, causing pigmented moth, was under strong selection.
The following is multiple choice question (with options) to answer.
some animals remove their hair coverings for | [
"naptime",
"lunchtime",
"mating season",
"scorching climates"
] | D | some animals shed fur in warm weather |
OpenBookQA | OpenBookQA-3567 | php
if ($day > 0)
{
if ($day < 5)
{
$start += ((5 - $day) * 86400);
}
$end += (7 - $day) * 86400;
}
$weekend['StartDate'] = date('d-F-Y', $start);
$weekend['EndDate'] = date('d-F-Y', $end);
return $weekend;
}
The following is multiple choice question (with options) to answer.
Saturday and Sunday together are | [
"72 hours",
"24 hours",
"48 hours",
"36 hours"
] | C | one day is equal to 24 hours |
OpenBookQA | OpenBookQA-3568 | 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.
Which of the following provides the best reason for squirrels vacating their forest? | [
"The forest is overrun with chipmunks",
"The forest is being harvested for lumber",
"Many acorns can be found on the forest floor",
"They want to start a new life"
] | B | if a habitat is removed then that habitat is destroyed |
OpenBookQA | OpenBookQA-3569 | 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.
Which of these is likely to get hot | [
"an angel",
"a kite",
"a bird",
"space craft"
] | D | if an object is hot then the surfaces of that object are hot |
OpenBookQA | OpenBookQA-3570 | combustion
Title: Why are fires smokey? Combustion, in chemical terms, is a reaction with a certain molecule and oxygen, and it produces, energy, $\ce{CO2}$, and $\ce{H2O}$ (That's how I learned it at least). So what makes a fire'smokey'? I had always thought that smoke was simply $\ce{CO2}$, but read that it was actually the result of incompletely 'combusted' material, yet I don't fully understand what this means. Is smoke made from material that starts to combust but stops before it finishes, or does it never even begin combustion? What would the chemical reaction be of a wood (Or other similar) fire that produces a lot of smoke? And finally, is there a certain element or compound that gives smoke its 'smokey' smell? Smoke is essentially aerated ash, unburned organics (including charcoal) and steam. You have to remember wood is not a pile of cellulose, but the remains of a dead organism. All the essential minerals that the plant needed for life are still in the wood such as calcium, phosphorous, sodium and potassium (namely potassium). When the organic matter is fully combusted, water and carbon dioxide are produced and the other elements are left as ash which can become aerated. When the water vapor reaches the cool air it condenses into a visible steam. However in real life wood is not fully combusted, but rather many unburned organic compounds due to a limited amount of oxygen, which give it its smell and fine aerated particles of charcoal which is scentless but very dark. This presence of unburned hydrocarbons in smoke is the cause of backdrafts in firefighting and can be demonstrated by lighting the smoke of a candle that has been blown out.
The following is multiple choice question (with options) to answer.
a byproduct of an open flame is | [
"cooking",
"warmth",
"cold",
"light"
] | B | fat is used to keep animals warm |
OpenBookQA | OpenBookQA-3571 | organic-chemistry
Title: What are the minimal chemical requirements for a food which we all can eat? I've been puzzled by the following though experiment for the past few days:
I want to make my own food from scratch, but I do not know where to start from.
I want to be 100% sure that what I eat will never contains something that can damage my body. For example: If you buy something from the local market you can not be 100% sure that it's safe to eat. (99.9 % maybe... but that's not 100%)
I want to ask you to tell me, how can I make a food that I can eat, or should I say - live on it, for the rest of my life, that's 100% safe, I can control every aspect of it's creation and has many combinations of taste because I love diversity.
Thank you for your time : )
Edit:
Because I realized my question is very broad and indeed is a little... too much scientific I want to close it. But before I do so, here's what I had in mind:
I wanted to take some chemical elements, put them in a jar, run some electricity, heat, whatever through it, filter it, do some additional processing and eat it.
I wanted to know if the stomach can take it, because I was going to eat food that's not hard to digest. Considering the three basic biomolecules used by the body are carbohydrates, lipids, and proteins, you would need to consume these three molecules only. Now we can choose three substances.
Glucose, one of the most basic carbohydrates, is needed for ATP production, so that would be a food choice there.
Any oil or butter will provide lipids.
Protein comes from a variety of sources. Meat is typically though of as the best, but nuts are a pretty good source too.
Since nuts satisfy proteins and lipids, I'd say honey roasted peanuts are the most basic food you could live off of, if you replace pure glucose for the honey.
The following is multiple choice question (with options) to answer.
What's necessary for the production of honey? | [
"maple syrup or corn syrup",
"a honey producing factory",
"a can of pesticide",
"liquid from plant flowers"
] | D | bees convert nectar into honey |
OpenBookQA | OpenBookQA-3572 | electromagnetism, electric-circuits, capacitance, voltage, inductance
Hopefully, visualizing things this way can give you an intuitive grasp of how a capacitor and inductor work together to form a resonant circuit.
The following is multiple choice question (with options) to answer.
You can see an electrical circuit in motion when | [
"drinking water",
"making toast",
"holding hands",
"eating carrots"
] | B | when an electrical circuit is working properly , electrical current runs through the wires in that circuit |
OpenBookQA | OpenBookQA-3573 | ocean, ocean-currents, tides
Physical effects, then, are likely to include direct effects on current speed, sediment, and stratification.
The obvious possible biological effect is from collisions. This is not my field, but as I understand it no effect is likely on small fish populations from collisions, although individuals may be affected. Collision risk for large animals (e.g. sharks and marine mammals) and for diving birds is a topic of active research, and is likely (especially for mammals) to depend on their behaviour around the devices. No large animal collisions have been reported on any of the prototypes undergoing testing so far.
A good review of possible effects on benthic organisms is provided by Shields et al (2011). These may include,
The following is multiple choice question (with options) to answer.
A shark will generally avoid eating fish that | [
"they are symbiotic with",
"are their main prey",
"are already bleeding out",
"they like the taste of"
] | A | remora fish eat food by attaching themselves to sharks and eating the food left behind |
OpenBookQA | OpenBookQA-3574 | species-identification
Title: What species of viper is this? I think that the snake in the pictures here below is a viper. I found it on a hiking trail on a mountain in Bulgaria. Height was about 2000 meters and the weather wasn't warm as you might expect in a late Spring days, but it seemed quite active.
If it really is a viper what species of viper? Otherwise what could it be? This is most likely the common European adder (Vipera beris). A list of the reptiles of Bulgaria lists it as occurring in the mountains of Bulgaria up to 2700 metres.
There are a couple of other contenders in the list of vipers, but two of them are incredibly rare (not found since the 1930's) and the last is the horned viper (Vipera ammodytes), which has distinctive horns on the tip of its nose.
The following is multiple choice question (with options) to answer.
Grass snakes live in what? | [
"trees",
"rivers",
"mountains",
"turf"
] | D | grass snakes live in grass |
OpenBookQA | OpenBookQA-3575 | Here is another approach:
Assume for the moment that the first appearance of the four digits is in increasing order. The places of their first appearance can be distributed in six ways, see the following figure. The places for the prospective second appearances have been marked by empty boxes, next to which is written the number of choices we have when filling them in. The last column shows the product of these numbers in each row. $$\matrix{ 2&3&4&5&\square_3&\square_3&\square_2&\square_1&&18\cr 2&3&4&\square_2&5&\square_2&\square_2&\square_1&&8\cr 2&3&4&\square_2&\square_2&5&\square_1&\square_1&&4\cr 2&3&\square_1&4&5&\square_2&\square_2&\square_1&&4\cr 2&3&\square_1&4&\square_1&5&\square_1&\square_1&&1\cr 2&3&\square_1&\square_1&4&5&\square_1&\square_1&&1\cr}$$ Summing the last column gives $36$. This has to be multiplied by $4!$ in order to compensate for the chosen order $2345$. It follows that there are $864$ admissible arrangements of the eight digits.
• One of the charms of mathematics is that there is always another way.... Aug 20 '17 at 13:52
The following is multiple choice question (with options) to answer.
Four times a year you will see a different | [
"climate",
"person",
"moon",
"star"
] | A | a new season occurs once per three months |
OpenBookQA | OpenBookQA-3576 | So our resultant is 30.8 meters, 35.8 degrees north of west. What we can see is that if there is an obstacle in the path here, some big rock that you want to avoid, you can get to the same place by taking a different route which is kind of obvious, but now we just sort of demonstrated that that's true using analytical techniques.
The following is multiple choice question (with options) to answer.
John Muir would likely set aside an area for | [
"superheroes and villains",
"oaks and chipmunks",
"bankers and politicians",
"cars and boats"
] | B | An example of protecting the environment is creating protected areas |
OpenBookQA | OpenBookQA-3577 | species-identification, zoology, entomology
Title: Species identification; clusters of big plump red bugs in Taipei I saw these red insects in Taipei near XinBeitou MRT station in the last week of April 2017, around lunch time. They were fairly active and would keep checking each other out with their antennae for a moment and then move on to the next. What struck me was the wide range of sizes and development in the groups. I didn't notice any feeding or mating that I could recognize, just a lot of walking around and checking each other out.
There are plenty of birds around (this is quite a green area) but I didn't notice any interest by birds in eating them.
I've also included a screenshot from google maps so you can see the location and the trees growing in these concrete structures.
The body of the largest individual is probably 2.5 centimeters long. I'm fairly certain these true bugs belong to the species Leptocoris vicinus, and carry the nickname of "soapberry bugs", which is specific to the subfamily Serinethinae. They're quite common in urban areas of Southeast Asia, which coincides nicely with where you encountered them.
Also, you had mentioned,
There are plenty of birds around (this is quite a green area) but I didn't notice any interest by birds in eating them.
Soapberry bugs, as well as many other types of insects, are able to freely congregate in large numbers, and in such exposed places, due to their bright coloration. Having such a bright color may indicate to some predators that the prey in consideration is toxic, a phenomenon referred to as aposematism.
source
source
And then, here's a map of their distribution, with Taipei holding marker #37. (source)
An interactive version of this map can be found here.
The following is multiple choice question (with options) to answer.
Some birds live in | [
"volcanoes that are erupting",
"several planets in the solar system",
"caves found under water",
"large area dominated by trees"
] | D | some birds live in forests |
OpenBookQA | OpenBookQA-3578 | forces, centrifugal-force
This acts to allows the rider to change the bikes trajectory, and pivot slightly about the rear wheel's point of contact and provide some lateral stability.
Aside: An interesting thing about the use of the front wheel to steer a motorcycle (or any bicycle for that matter) is 'mechanical trail' or 'caster'. This quantity is one thing that I was not aware of until I designed and made my own downhill racing bike many years ago. Mechanical trail is the perpendicular distance between the steering axis and the point of contact between the front wheel and the ground. It may also be referred to as 'normal trail'. This quantity is what determines how a bicycle handles when steering. See the picture below
If the trail is positive (trail shown by the green arrows), the bike will be stable. The more trail, the "heavier" the steering. If this distance is (too) negative, you cannot steer you bike (try turning the handle bars of your push bike the wrong way around [we have all done it as kids but I don't recommend it!].
For me, the reasons for trail playing such a key role in the steering stability of a bike is (very loosely) 'causality'. The trail or 'lead' allows the rider to adjust the lateral force on the front tyre as required before the point of contact of the tyre travels the trail-distance. This is a poor, on-the-fly explanation of trail and why it works the way it does and I would be interested to hear some of the other guy’s thoughts on this... but that is another question entirely!
I hope this helps.
The following is multiple choice question (with options) to answer.
pushing on the pedals of a bike cause that bike to gain | [
"a lightshow",
"new tires",
"kinetic motion",
"extra weight"
] | C | pushing on the pedals of a bike cause that bike to move |
OpenBookQA | OpenBookQA-3579 | bond
Title: Is energy required to form bonds [phase change] My question is if any energy is required to form bonds, for instance when there is a phase change?
If I am correct, energy might be required in the beginning, to make the reaction start and then release a bigger amount of energy than it was putted in. However, in terms of molecular behaviour in a phase change, I think there should not be any energy required to make the molecules to form bonds, if they are placed in a system which has a lower temperature than the molecules. Would they not lose the kinetic energy after a specific time? Bond formation always lowers the energy of the system (or bond formation is a consequence of lower energy, take your pick.)
Indeed, you may have to add energy, because presumably certain bonds must break in order to rearrange the atoms.
Adding energy won't guarantee formation of much higher energy isomers, because the atoms have a large amount of kinetic energy, and so they can just as easily turn around and go back whence they came.
Sometimes the kinetic energy can be dissipated by solvent, collisions with inert gasses, etc. and then you may end up with a measurable quantity of the higher energy species.
The following is multiple choice question (with options) to answer.
What requires energy for growth? | [
"wood",
"paper",
"rubber",
"anteater"
] | D | an organism requires energy for growth |
OpenBookQA | OpenBookQA-3580 | 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 useful product can be made from the moving winds? | [
"metal",
"wood",
"bananas",
"electricity"
] | D | when a hurricane moves over land , that hurricane will decrease in strength |
OpenBookQA | OpenBookQA-3581 | muscles, lungs, human-physiology
Title: Why is there smooth muscle in our bronchioles? Having muscle tissue in our bronchioles that can constrict seems like a poor choice for tissue. Why would our airway want to ever close up? Wouldn't it be more beneficial for our bronchioles to just remain open? There are at least two things to consider.
First, ability to limit airflow is a defense mechanism for animal. Imagine getting into area of some sort of toxic evaporation, e.g. CO2 cloud near volcano , then it makes sense to decrease delivery of toxin via lungs to minimum. As I understand, that is what an allergic asthma attack. (Sorry for not providing good enough source of that)
Secondly, you are incorrect in assuming that normal state is "dilated". Dilation of branchioles is sympathetic ("fight-and-fly") response of the nervous system to something like danger, that requires short-term boost in energy production. That is, by default, your airflow is limited. Probably, to limit amount of energy you effectively burn via oxygenation. But most importantly, you leave yourself a reserve in terms of oxygen supply for critical moments.
Some more information you might find here.
The following is multiple choice question (with options) to answer.
the muscle that never sleeps takes oxygen rich what to the body | [
"tar",
"plasma",
"antibodies",
"acid"
] | B | the circulatory system brings oxygen from the lungs to the rest of the body |
OpenBookQA | OpenBookQA-3582 | electromagnetism, momentum, conservation-laws, classical-electrodynamics
There is a very nice example of all this, worked out concretely, in these notes.
The following is multiple choice question (with options) to answer.
An example of conservation is | [
"jogging",
"reducing ethanol use",
"hiking",
"raking leaves"
] | B | An example of conservation is not using fossil fuel |
OpenBookQA | OpenBookQA-3583 | machine-learning, classification, decision-trees, information-theory
Weather and Wind both produce only one incorrect label hence have the same accuracy of 16/17. However, given this data, we would assume that weak winds (75% YES) are more predictive for a positive outcome than sunny weather (50% YES). That is, wind teaches us more about both outcomes. Since there are only few data points for positive outcomes we favor wind over weather, because wind is more predictive on the smaller label set which we would hope to give us a rule that is more robust to new data.
The entropy of the outcome is $ -4/17*log_2(4/17)-14/17*log_2(14/17)) =0.72$. The entropy for weather and outcome is $14/17*(-1/14*log_2(1/14)-13/14*log_2(13/14)) = 0.31$ which leads to an information gain of $0.41$. Similarly, wind gives a higher information gain of $0.6$.
The following is multiple choice question (with options) to answer.
if weather is stormy then there is a greater chance of | [
"everything getting wet",
"naps",
"lottery wins",
"lunch"
] | A | if weather is stormy then there is a greater chance of rain |
OpenBookQA | OpenBookQA-3584 | polymers
$$\ce{(CF2CF2)_{n} + 2nF2 -> 2nCF4}$$
Similar things can occur under extreme conditions (temperature and pressure) with:
Boranes
Nitric acid
80% NaOH or KOH
Aluminum chloride
Ammonia, some amines, and some imines
The following is multiple choice question (with options) to answer.
An example of combined substances could be | [
"diamonds",
"tin",
"cake",
"water"
] | C | An example of combining two substances is pouring one substance into the other substance |
OpenBookQA | OpenBookQA-3585 | material-science, everyday-life
Title: Is there a physical reason steel balls are not suitable to play billiards with? Steel is an elastic matter and is often used when demonstrating elastic collisions. We also make springs from it.
Due to these properties and for its relative low price, it seems obvious to me to use them to play billiards.
But I don't find any information on the internet about this. Maybe I miss something very obvious? Q: No Steel balls for billiards.. Maybe I miss something very obvious?
A: Yes Steel balls are way too heavy or they weigh too much ;) in both cases they are way, way too much weight.
The density of steel would result in a much lower speed from conservation of momentum of the cue and momentum of the ball. when driving the ball with a fast cue, a much higher shock to the cue tip would occur causing more injuries to players and cue tips, when impacting a ball of significantly greater mass. So the result would be;
more cue tips would break off;
fast breaking cue balls would not be possible with the same light weight cue
More RSI injuries of high impact shock on pool players
4) balls that fly off the table become airborne heavy cannonballs that might cause injury to players standing around the pool table for their next turn. ;)
The following is multiple choice question (with options) to answer.
Which would you avoid filling a beachball with? | [
"nitrogen",
"sand",
"oxygen",
"helium"
] | B | a beach ball contains gas |
OpenBookQA | OpenBookQA-3586 | evolution, ornithology, palaeontology
One thing those many, many bird and proto-bird fossils also made clear is that the traits of modern birds (feathers, wings, toothless beaks, etc) didn't evolve in a simple line from non-bird to bird. Many of those traits evolved convergently in several lineages, were lost in some, maybe regained in others, and feathers in particular turn out to be a widespread dinosaur feature that cannot be considered a uniquely bird trait anymore (unless we want to call T-rexes "birds"). Still, saying "beaks evolved several times" or "feathers evolved several times" doesn't mean that birds, let alone modern birds, evolved from several different ancestors. It can mean that the common ancestor of birds had lots of variously bird-like more-or-less distant cousins living around the same time.
The following is multiple choice question (with options) to answer.
If a bird has a larger beak than its friends, it likely had | [
"mother without a beak",
"father with a long trunk",
"parents with smaller beaks",
"ancestors with similar beaks"
] | D | the thickness of the parts of an organism is an inherited characteristic |
OpenBookQA | OpenBookQA-3587 | organic-chemistry, alcohols, organophosphorus-compounds
Animal studies are consistent in reporting a decrease in the body weight of rats receiving ethanol solutions as the only source of liquids. Concentrations of ethanol as low as 5% (v/v), which are similar to the ethanol content of a Brazilian beer, or as high as 40% (v/v), solution similar to spirit drinks, are related to decreased body weight gain (9). Similar results have been reported for 20% (v/v) ethanol solution (10).
Different results have been obtained for malnourished animals. Da-Silva et al. (11), studying rats which had been treated with ethanol for 90 days, reported a significant weight gain by malnourished rats (50% food restriction) drinking a 20% (v/v) ethanol solution when compared to malnourished rats drinking water. A more recent study (12) reported improvement in somatic and motor development and a decrease in the mortality rate of the offspring of malnourished rats drinking low doses of ethanol (5%, v/v). These data suggest that malnourished rats can benefit from ethanol calories.
In summary, in spite of the large number of studies on the effects of ethanol in well-nourished animals and humans, there is still controversy about how well ethanol-derived calories can be utilized. Fewer studies are available about special physiological conditions such as malnutrition. Over the last few years, scientific research has mainly focused on obesity, an increasing problem in developed countries, which led us to the false belief that malnutrition was no longer a problem worth investigating. However, there are still 800 million malnourished people in the world (13). The decreasing interest of the scientific community in problems related to malnutrition has left many questions without an answer. Ethanol consumption and its consequences on the malnourished organism are among them.
In view of the importance of malnutrition in Brazil - 22% of the population or 40 million people are malnourished (14), as well as ethanol consumption and alcoholism - 11% of Brazilian population are alcoholics (15), the aim of the present study was to assess the use of ethanol calories in a dose/effect model by evaluating body weight before and after the installation of malnutrition.
The following is multiple choice question (with options) to answer.
eating food that contains pesticides can have a negative impact on humans and | [
"rocks",
"golden retrievers",
"sticks",
"blankets"
] | B | eating food that contains pesticides can have a negative impact on humans |
OpenBookQA | OpenBookQA-3588 | rd, eg, qg, l1, 80, pj, kk, bv, hk, mc, sw, jh, pn, ty, ck, an, tf, rf, rm, n7, s5, yf, fk, ai, lg, ih, eo, 32, 2x, hh, em,
The following is multiple choice question (with options) to answer.
all animals | [
"fly",
"are telepathic",
"dig",
"intake gaseous elements"
] | D | all animals breathe |
OpenBookQA | OpenBookQA-3589 | meteorology, atmosphere, wind, air-currents
Title: Where does wind come from? Wind is (according to Wikipedia) the flow of gases on a large scale.On the surface of the Earth, wind consists of the bulk movement of air.
What forces would cause such a mass movement of air? Wind is caused by pressure differences. Think of a balloon full of air; poke a hole in it and the air comes out. Why? Because the pressure in the balloon is higher than outside, and so to regain equal pressure, mass moves and that is the wind.
There is a bit more to this in the atmosphere as the Earth rotates and near the surface friction also plays a role. The equation of motion is the Navier-Stokes and in vector form in Cartesian space is:
$$\dfrac{\partial\mathbf u}{\partial t} = - \mathbf u \cdot \nabla \mathbf u -\dfrac{1}{\rho}\nabla p-2 \mathbf \Omega \times \mathbf u + \mathbf g + \mathbf F$$
In this equation, $\mathbf u$ is the vector wind, $(\mathbf u \cdot \nabla)$ is the advection operator, $\rho$ is density, $\mathbf \Omega$ is the vector rotation of the Earth, $\mathbf g$ is effective gravity and $\mathbf F$ is friction.
The LHS is the time rate of change of the wind at a point in space (as opposed to following the parcel). The RHS represent a number of factors that produce a change in the wind. From left to right:
Advection of momentum (non-linear)
Pressure gradient force (this is wind blowing from high to low pressure)
Coriolis force (this turns wind to the right in the NH and left in the SH and causes the wind to flow parallel to isobars)
gravity (provides hydrostatic balance with the PGF in the vertical)
Friction (in the boundary layer you may see this as $\nu\nabla^2\mathbf u$)
The following is multiple choice question (with options) to answer.
wind is used for producing | [
"cupcakes",
"smores",
"excited particle flowing",
"plants"
] | C | wind is used for producing electricity |
OpenBookQA | OpenBookQA-3590 | par(mfrow = c(1, 2))
plotHist(4, 0.5)
abline(v = 2, lty = 2)
arrows(2-0.5*0.9, 0.17, 2, 0.17, col = "red", code = 3, length = 0.1, lwd = 2)
plotHist(6, 0.5)
f4(0.5)
f6(0.5)
f1000(0.5)
par(mfrow = c(1, 2))
plotHist(4, 0.6)
plotHist(6, 0.6)
f4(0.6)
f6(0.6)
The following is multiple choice question (with options) to answer.
A fawn's colors helps it blend in with the landscape in | [
"Autumn",
"oceans",
"icy lakes",
"Winter"
] | A | An example of camouflage is when something has the same color as its environment |
OpenBookQA | OpenBookQA-3591 | magnetic-fields, earth
Title: Would a compass on its side point at the ground? From a point just north of the equator, A straight line to the Magnetic North would be through the earth. If a compass was turned on it's side, would the north pointing arrow point toward the ground along that straight line? A compass is usually used to find the direction of the horizontal magnetic field of Earth at that point. The needle of a compass is very light and thus its efficiency decreases when the compass is not in the horizontal plane at that point (due to gravity).Therefore, where the compass would point will become unpredictable. But, yes, in ideal conditions, the compass would point along the straight line joining that point to the north pole.
The following is multiple choice question (with options) to answer.
If someone wants to walk towards the magnetic north pole they should | [
"walk to the east",
"walk parallel to the way their compass is pointing",
"walk perpendicular to the way a compass is pointing",
"catch a bus ride"
] | B | a compass 's needle lines up with Earth 's magnetic poles |
OpenBookQA | OpenBookQA-3592 | biochemistry, botany, plant-physiology, photosynthesis, agriculture
The above image is an example of a "potato battery" made without the potato. Identical setup and the energy obtained is identical given everything else the same.
Potato power- er, metal power?
This experiment is supposed to demonstrate the concept of an electrochemical cell. Electrochemical cells obtain their energy from the reduction-oxidation reactions that happen between two metals with different reduction potentials. When two metals - such as copper and zinc - are placed in a medium that permits the exchange of electrons and ions, an electrical gradient is produced as electrons move from one metal to the other and ions move the other direction. This gradient can then be captured and used to do work such as powering a lightbulb or an AI.
In the potato powered example, the power comes from zinc and copper. If you want a more powerful battery, use more zinc and more copper- not a bigger potato. If that is not good enough, try replacing the zinc with something like lithium- this is what we've done with modern, rechargeable batteries.
In truth, the potato battery would be better described as a normal battery that just happens to be inserted into a potato. You'll make a better battery if you use copper pennies and aluminum foil in vinegar.
I do not mean to shoot down your idea, and I am glad you are looking into renewable energy sources- but you may be better served by a class on electricity and batteries than by asking questions on biology.SE!
EDIT: I would assume that the electrical potential of this kind would also kill the plant, given that you're essentially electrocuting it. However, I was unable to find any information on the resistance of potato plants to electrocution.
The following is multiple choice question (with options) to answer.
Different plants draw different minerals so to save the land you need to | [
"water less",
"switch crops yearly",
"watch the moon",
"bring in dirt"
] | B | crop rotation renews soil |
OpenBookQA | OpenBookQA-3593 | general-biology, habitat
Title: How does life change when you dig deeper? I've just realized that I have no idea what life / biotopes / soil looks like when you dig deeper than a few meters.
I know that in the first meter of soil you can find all sorts of live animals (like moles and rabbits), insects (like ants, but many more), plants, and single-celled organisms, of course.
But how does that change when you get to the depth of a metro station (below 30m)? When you plan to build a metro, do you have to consider that you might destroy a biotope?
I guess there is a point from which you will quite certainly not find animal/plant life in the soil anymore. This will, of course, depend on where exactly you are. But can you give a rough estimate of how deep we're talking? 50m? 100m? 1km? Extremophile bacteria and archea are living very deep beyond our imaginations. This is what you need for general composition at different depths. And this and this is for the deepest living organism known ! Following is image from (Manson et al 2010) which shows at what depth you will get bacteria
Even more deeper, Wold's single species ecosystem, Desulforudis audaxviator which can be found 3 km below sea level.
The following is multiple choice question (with options) to answer.
plant life vessels can be harvested in the ground which will change the | [
"moonlight",
"surrounding areas habitat",
"starlight",
"sunlight"
] | B | farming changes the environment |
OpenBookQA | OpenBookQA-3594 | remote-sensing, forest
Title: How is tree age estimated? I am trying to study about forest biomass and carbon amount of forest.
First of all, I studied some papers, they mentioned that age of forest is related to the biomass. So, How do we measure the age of tree? What are the practical ways used to estimate tree age? Biomass itself isn't a great measure of tree age because the size of a tree is affected by a number of factors. Assuming the same species of tree:
Soil nutrients: more nutrients in general means better growth for most species
Availability of water: scare water means less growth
Availability of light: a tree with more light grows more than one that's constrained
A tree with good soil, lots of water and light will grow more than one without those things, so the same age of tree could be very different sizes and biomasses. The only way to get an exact age of a tree is to get a core sample or cut it down and count the rings, every ring represents a growing year. A tree that grows very little will have narrowly spaced rings, a tree that grows a lot has wider space rings as it's putting more biomass. Note that wood density is also an important measurement for biomass, the denser the wood the more biomass is compacted in the same amount of space. Slower growing trees tend to be more dense, tree twice the size of another may not be twice the mass.
That's for a single tree, but you're asking about forests. It's impractical to core sample a million trees, but you can core sample a fair number of live ones or take samples of fallen ones. Along with measurements of circumference and height you can build a database and estimate the average age of the rest of the trees in the forest from their heights and circumferences. It's also possible to estimate the biomass of the forest from estimating the number of trees in and using an average biomass.
The following is multiple choice question (with options) to answer.
the number of rings in a tree trunk can be used to estimate what? | [
"oldness",
"starvation",
"hydration",
"location"
] | A | the number of rings in a tree trunk can be used to estimate the age of the tree |
OpenBookQA | OpenBookQA-3595 | sun
Title: Is there an instance where the sun sets or rises partly, then return back? I am reading Longest Sunset from XKCD. At first, I've thought that he mentions these phenomena just for fun, but it turns out to me that it might happens, based on the level of somewhat seriousness that I perceive from his writing. He doesn't talk about that in detail.
For the sunset:
Sunset starts the instant the Sun touches the horizon, and ends when it disappears completely. If the Sun touches the horizon and then lifts back up, the sunset is disqualified.
I'm not sure if the sunset is disqualified is because it happens, but we don't count it, or because he's just making fun. But I can't prove that this cannot happen. The more we head to the poles, the shorter the night is. Ultimately there will be a point that the sun still sets, but not completely, right?
For the sunrise:
For the purposes of our question, this is not a sunset:
The phrase for our purposes strengthen my doubt that he is being serious. The logic is the same above.
But these two illustrations are in the series of other apparently amusing ones, which are the sun as the cell in division, or as the egg in hatching (if you read the book, you will see this effect stronger).
So, is there an instance where the sun sets or rises partly, then return back? Yes, such sunrises happens every year at the beginning and end of the polar nights at high latitudes. One can have a few days with a glimpse of the sun but disqualified sunsets and sunrises.
Sunsets occur at the end of the midnight sun period by the end of the summer, the first sunset is not complete.
Sun at it's highest elevation at midday. (To be honest, the picture might be taken the day after the first sunrise, as some mountains are hiding the horizon.)
Here is e.g. an article from Svalbardsposten, the northernmost newspaper in the world, reporting of the first rays of sunlight after the polar night and some pictures from the last sunrise/sunset before the polar night in northern Sweden.
The same occurs at the southern polar circle and south thereof, unless it's cloudy...
Update: here is a great time laps from Davis Station in the Vestfold Hills showing exactly what you asked about: Mid winter
The following is multiple choice question (with options) to answer.
he sun rising and setting causes cycles of | [
"evolution",
"available luminance",
"dancing",
"cooking"
] | B | the sun rising and setting causes cycles of day and night |
OpenBookQA | OpenBookQA-3596 | mechanical-engineering, automotive-engineering, energy
Title: How much braking force do cars generate? I've been trying to find actual figures for the braking power of cars (in order to determine things like stopping time). As I understand it this comes in two parts: the maximum force that the brakes can apply on the tires, and the maximum force the tires can apply on the road.
I'd love to find figures for particular cars (or brake systems or tires) but I would be fine with any figures for actual cars under reasonable conditions. It's easy to find math problems of this sort online but I don't expect their figures to have much in common with the real world.
If someone could point me in the right direction (car data sheets, third party testing, government regulations, etc.) I'd be very much obliged. To elaborate on my comment; obviously generated braking force is defined by how hard you push the braking pedal. The required force to lock the wheels (given that ABS is disabled) depends on how much traction the tyre has. Let's say our tyre has a constant friction coefficient of 1. That's a simplified situation where the tyre has as much traction force, as there is force on the tyre by the vehicle's weight.
This allows you to decelerate(or accelerate) with a maximum of 1G or 9.81m/s2, before your tyres start slipping. That means that you'd get to a stop in 2.83s when travelling 100km/h. You can see from this figure, that most supersports cars are limited in their 0-100 time by the tyres. They use as wide tyres as they can on the driven wheels, to maximise traction. Heating up the tyres and lowering their pressure, and a slick surface on dry hot asphalt further increases their traction. But it doesn't allow you to accelerate to 2G or something.(except for crazy top fuel dragsters) But that's why i'm rather sceptical about Tesla's promised 0-100 figures for the announced roadster.
In reality, a friction coefficient is not close to constant and way more complex. In reality, your tyres are always slipping, which is the main reason they wear out. It gets worse in corners, acceleration, braking etc. but it's always present in a certain amount.
The following is multiple choice question (with options) to answer.
On what surface does a braking car have the most trouble? | [
"gravel",
"oil slick",
"sand",
"asphalt"
] | B | skidding causes speed to decrease |
OpenBookQA | OpenBookQA-3597 | 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.
An item such as a soda can is broken down. This means that the soda can is now | [
"completely whole",
"all together",
"an intact item",
"in detached components"
] | D | break down means change from a whole into pieces |
OpenBookQA | OpenBookQA-3598 | neurophysiology, skin
As for why the smaller the contact, the greater the pain? Perhaps someone else can supplement, but my speculation is that when you apply pressure, other receptors (pressure, etc.) are also firing signals. This can cause a net dampening of heat/pain signal from the free nerve endings. Although not exactly the same process, you can think of like lessening the pain in one body part by inflicting pain in another (e.g. squeezing hands really tightly and clenching jaw after stubbing toe). When you are only slightly making contact with the port, only your free nerve endings may be firing, causing uninhibited signal. The pain may not be able to be replicated with intact skin simply because the free nerve endings under the epidermis are not firing - whatever miniscule current passing through the port cannot activate the receptors through an epidermal layer.
Again, this last part is just my reasoning. I don't think this has been studied, and there is so much variability in the human body that you would probably need a personal nerve conduction study for a definite answer to this phenomenon you've experienced.
The following is multiple choice question (with options) to answer.
If a person blows on another person's arm, then nerves will | [
"curl up and die",
"signal to the sky",
"make more nerves in that area",
"alert the brain of this"
] | D | nerves can be used to feel heat and pressure on the skin |
OpenBookQA | OpenBookQA-3599 | Thanks for detailed explanation.
20. Jan 31, 2012
### LCKurtz
Good job of catching that eumyang. I hadn't caught that his difficulty was with the fact I had used "c" instead of "a" in my explanation.
The following is multiple choice question (with options) to answer.
A being which has migrated may have | [
"sought warmth",
"preferred snow",
"enjoyed the cold",
"wanted to freeze"
] | A | An example of migration is birds flying south in the winter |
OpenBookQA | OpenBookQA-3600 | cellular-respiration
Title: Do cold blooded animals generate any heat? In explaining energy and work to an 8 year-old I said that all conversion of energy generates heat as a by-product. For example, cars generate heat in their engines and running generates heat in our bodies. Then the 8 year-old said, except for cold-blooded animals.
So my question is, do cold-blooded animals generate any heat in their conversion of stored energy (food, fat, etc) into motion? If they generate heat, why are they cold-blooded? They do generate heat. They just do not SPEND energy specifically on heating their bodies by raising their metabolisms. This is a form of energy conservation. The metabolic rate they need to live is not nearly enough to heat their bodies.
An example of spending energy to heat the body is seen in humans shivering. Here muscle is activated not for its usual purpose, but to function as a furnace. "Warm-blooded" and "cold-blooded" is somewhat a misnomer. The correct way to think of it is...
Endotherm or ectotherm. Does the heat primarily come from within (endo) or from the surroundings (ecto). Endothermic animals include mammals. Most of their body heat is generated by their own metabolisms. Ectothermic animals include reptiles and insects. They absorb most of their body heat from the surroundings. This is not the same as saying they let their body temperature fluctuate with their surroundings, some avoid this by moving around to accomodate themselves.
Homeotherm or poikilotherm. Homeotherms want to maintain homeostasis for their body temperatures. They don't want it to change. Poikilotherms do not exhibit this behaviour, instead their body temperatures vary greatly with the environment.
We can have endotherm poikilotherms, such as squirrels, who let their body temperature drop while hibernating. Endotherm homeotherms, such as humans, where temperature is constant by means of complex thermoregulation. Ectotherm homeotherms, such as snakes (moving into shadow or into the sun to regulate temperature), and ectotherm poikilotherms, such as maggots.
The following is multiple choice question (with options) to answer.
If an animal gets too cold for its body to perform its functions, that animal will | [
"perish due coldness",
"laugh to death",
"do math",
"float"
] | A | if a living thing becomes too cold then that living thing will die |
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