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Monday, May 14, 2018

Why does a wound itch before it's healed?

Why does a wound itch before it's healed?


Why does a wound itch before it's healed?

Posted: 13 May 2018 07:09 PM PDT

Do bees ever fight over a single flower?

Posted: 13 May 2018 06:08 PM PDT

How would an AI be affected if humans decided to lie to it during learning?

Posted: 14 May 2018 05:18 AM PDT

I had this thought, as if for example Facebook asks for your opinion on an action taken (Which could later be used or is currently used to train AI's) And instead of clicking the smile/happy emoji option i chose the angry/sad emoji option. Could that make the AI useless thus delay it's development, break it completely or make it destructive?

submitted by /u/Sikator
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Physics When two EM waves are in destructive interference, where does the energy go to?

Posted: 14 May 2018 05:25 AM PDT

Basic example I can think is in a Mach-Zehder interferometer. If the two wave fronts that collide are in destructive interference, they "cancel out".

I never understood what this really means. Mathematically it is quite obvious, but in the physical world, the energy has to go somewhere.

submitted by /u/MadameBanaan
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What happens when two or multiple sperm fertilize a single egg simultaneously?

Posted: 14 May 2018 04:12 AM PDT

I know fraternal twins occur when two separate eggs are fertilized and identically twins occur when a single egg splits, but would this scenario cause a birth defect or a failed pregnancy or something else?

submitted by /u/sloposaurus
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Does Saturn's largest moon Titan really has "Methane Lakes"?

Posted: 14 May 2018 05:13 AM PDT

My dad explained to me that day about Saturn's largest moon Titan. The only moon with a planet-like atmosphere. My dad also told me that that moon has petroleum lakes which space.com calls "methane lakes". Is this true and is there a possibility of a living organism there?

submitted by /u/muthanii
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Could we accelerate decay of say U235 using a linear accelerator?

Posted: 14 May 2018 05:04 AM PDT

Why do microwaves cook/heat things faster than ovens, when ovens reach higher temperatures?

Posted: 13 May 2018 06:18 PM PDT

e.g stick a Hot Pocket in the microwave and you're good to go in about 2 1/2 minutes, but put it in the oven, and it takes about 10-15. According to the box, anyway.

submitted by /u/NeuroSama
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Do insects get sick? like do ants get colds or do bees get STI's?

Posted: 13 May 2018 11:04 AM PDT

If space was filled with air, would we be able to hear our sun?

Posted: 13 May 2018 08:42 AM PDT

Hey, I just watched this video, in which Chris Hadfield debunked some myths about space and beeing an astronaut.

At 4:37 he mentioned, that we aren't able to hear the sun, because there's no medium which can transfer the sound to earth.

But If there was one (air eg), would we be able to hear it and if so, how loud would it be?

submitted by /u/Ente69
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How was the relationship between Pascal's tiangle and the binomial theorem discovered?

Posted: 13 May 2018 03:47 PM PDT

I was reading the history of Pascal´´´'s triangle and I noticed it's history goes as far as the 2nd century as a math/logical experiment. So I was wondering if the understanding of the Pascal triangle had something to do with the understanding of the binomial theorem, or the relationship arises from a coincidence.

submitted by /u/ullyses85
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Do other languages have a preferred way to order adjectives?

Posted: 13 May 2018 03:21 PM PDT

I learned recently that in English we typically order adjectives opinion-size-physical quality-shape-age-colour-origin-material-type-purpose, and would like to learn more about it. Has it always been like this? Is it like this in other cultures? Are there theories as to why this developed?

submitted by /u/MoreGeneral
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Producing gold with antimatter?

Posted: 14 May 2018 05:16 AM PDT

If i shoot a mercury atom with an antihydrogen atom would it just anhiliate one proton and one electron and create gold? Only theoretically haha

submitted by /u/mdmax123
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How do therapists treat antisocial personality disorder?

Posted: 13 May 2018 08:22 PM PDT

This includes medications and therapy depending on if the patient is born with it or acquired it

submitted by /u/Scarab3000
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How are potential energy and entropy related?

Posted: 14 May 2018 04:47 AM PDT

There seem to be two basic laws governing most (conservative in the physics sense - let's ignore cases where the potential doesn't exist) systems:

  • In the long run, things "roll downhill" from high potential to low. Physics even formalizes this idea, since the force field F is the negative gradient of the potential field by definition provided F is conservative.

  • Energy tends to disperse, i.e., the second law of thermodynamics.

Is there a relationship between these two? In particular, is there a reason that high potential seems to correspond to low entropy?

When I play with the idea, I seem to get conflicting results:

  • The classical heat engine, with a hot reservoir and a cold one, doesn't seem to be extracting potential energy - it's extracting the kinetic energy of the motion of the molecules. But it is a thermodynamically irreversible process, so entropy is increasing. This seems to argue against a connection.

  • A ball bearing on the head of a pin is at a maximum of potential among stable states, and at a minimum of entropy since there is only one microstate corresponding to this macrostate. When perturbed, it seems like entropy rises, since the broken symmetry of the system should require an extra parameter to describe (namely, which direction the bearing fell) and because there are now many possible microstates corresponding to the "bearing has fallen off the pin" macrostate. Potential falls, of course, since the bearing is dropping. So this would seem to argue for a connection.

  • A ball bouncing elastically on the floor has oscillating potential, although it tends to decrease over time as the ball's bounces go less and less high. But this is a spontaneous process, and the elasticity of the bounces means entropy increases. This argues against a connection.

So what gives? How can both "force pulls towards lower potential" and "entropy increases" be physical laws if they seem to give contradictory answers? Or maybe more succinctly: how can thermodynamics and mechanics play nice?

submitted by /u/Chel_of_the_sea
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Does the human body actually consume water or is it just stored, used, and expelled?

Posted: 13 May 2018 03:45 PM PDT

Are there any processes in the human body that actually consume the water? As in if I drink 32 ounces of water, would I then expel 32 ounces over the next X-hours or would it be a lower amount? Thanks!

submitted by /u/Blargasaur
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What is the highest level of oxygen that a human can safely live in?

Posted: 13 May 2018 04:50 PM PDT

I know that our earth's atmosphere is about 21 percent, but what is the highest percentage of oxygen in which humans can safely live?

submitted by /u/nickmavrick
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Why does all garbage basically smell the same, even though its components can vary widely?

Posted: 13 May 2018 06:04 PM PDT

Can an animals be gay?

Posted: 13 May 2018 07:24 PM PDT

Edit-ignore the 's' in front of animal

submitted by /u/M33RHARIS
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Question about mountains and the behavior of hurricanes?

Posted: 13 May 2018 04:52 PM PDT

I have heard that the elevation of Mauna Kea (13,000) and Mauna Loa (13,000) on the Big Island as well as Haleakala (10,000)on Maui actually obstructs approaching hurricanes and causes them to veer from hitting Maui and the Big Island. Is there any truth to this?

submitted by /u/cakenoodle
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What is the cutoff point for the number of atoms or molecules needed to declare their state of matter?

Posted: 13 May 2018 10:32 AM PDT

For example, how many water molecules must there be in a chamber to declare them a gas? At what point can you declare them a liquid? Solid?

submitted by /u/NeodymiumCandy
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Do meteors enter our atmosphere all the time or no?

Posted: 13 May 2018 08:13 PM PDT

Sunday, May 13, 2018

Are we producing more atmosphere than we lose at this point in time?

Are we producing more atmosphere than we lose at this point in time?


Are we producing more atmosphere than we lose at this point in time?

Posted: 13 May 2018 04:14 AM PDT

I guess my question is pretty simple. At this point in time is the planet producing more atmosphere than we are losing to solar wind or are we slowly losing atmosphere?

What are some of the factors affecting our atmospheric production or decline?

Is our atmosphere undergoing any kind of changing state? As in, more oxygen rich, less oxygen rich? Etc....

submitted by /u/Runtowardsdanger
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How much electrical conductance (if any) is lost, when a metal is oxidized?

Posted: 13 May 2018 04:13 AM PDT

Why does egg turn white when you cook it?

Posted: 12 May 2018 08:16 PM PDT

What are the effects on copper pipes when they are connected to a house's electrical ground?

Posted: 12 May 2018 08:04 PM PDT

In some regions, if a house has a buried copper water supply line, it must be connected to the electrical ground.

How does this affect the copper pipe? I've read frequently that people suspect it increases corrosion, but if only copper and brass are used, I'm not sure how that would happen.

submitted by /u/Hatsuwr
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What's the deepest point through the planet that we believe life to exist?

Posted: 12 May 2018 09:39 PM PDT

How do magnetic poles spontaneously flip?

Posted: 12 May 2018 01:16 PM PDT

Every so often the Earth's magnetic field flips. What is the cause of this. How does it relate to a small magnet flipping poles? Bonus: In the instant the poles flip is there a instant when there is no magnetic field?

submitted by /u/usualservice
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Do non-human primates have dominant handedness like humans do?

Posted: 12 May 2018 10:09 AM PDT

How can I visualize a matrix product with a vector?

Posted: 12 May 2018 12:19 PM PDT

I have trouble wrapping my head around it. For example: say you have a matrix A, vector x, and a new vector Ax=x'. How can I tell what the components of x' stand for? In what way is it connected to a change in basis?

submitted by /u/SlimShady123_
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If cancer and psoriasis are both overactive cell growth, what is it that makes them different?

Posted: 12 May 2018 11:07 AM PDT

If you were to compare skin cancer vs. psoriasis they are both described as overactive cell growth, though with different results and degrees of danger. A) how are they different, and B) what is it that makes cancer more dangerous than psoriasis?

submitted by /u/_migraine
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Why do grapes and raisins differ in health benefits?

Posted: 12 May 2018 11:27 AM PDT

Why are the most common screen resolutions multiples of 360?

Posted: 12 May 2018 11:06 AM PDT

There used to be a variety of screen resolutions and different aspect ratios... TVs were 4:3, monitors were all over the place and it seemed like 16:10 might become the standard when HDTV came out and everything shifted towards 16:9.

For a while we had 720p (1280 horizontal x 720 vertical pixels), then 1080p (1080 vertical pixels). Those vertical resolutions are 3602 and 3603.

Some monitors are now 1440p (3604), and 4K televisions are 2160p (3606). I guess poor 1800p (360*5) was unwanted.

Anyway, why are all of the common resolutions multiples of 360? Is it just a coincidence, or is there some reason for it? There were 1600 x 900 monitors, and other 16:9 resolutions are out there. There are a lot of options for multiples of 9 that could have been used... did 40*9 just get to be the lucky winner?

submitted by /u/chocoboat
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Can the beam quality parameter (M^2) for a laser be less than 1?

Posted: 12 May 2018 10:17 PM PDT

Like the title asks, is it physically possible for the beam quality parameter of a laser to be less than 1? Or is this just not how the M2 parameter works?

submitted by /u/Sullivanseyes
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Why is there a small oxygen absorber package in a bag of Beef Jerky?

Posted: 12 May 2018 11:24 AM PDT

Title.

submitted by /u/Andratini
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How "big" is the window-of-opportunity for re-entry into Earth's atmosphere, from a burn-up/skip off perspective?

Posted: 12 May 2018 09:20 PM PDT

Are mosquitos considered venomous?

Posted: 12 May 2018 08:27 PM PDT

What is an intermediate?

Posted: 12 May 2018 04:37 PM PDT

How do we know intermediate steps take place in a chemical reaction if they cannot be measured. Additionally, why are they important in measuring rates.

submitted by /u/WithMayo
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How would you determine the molecular identity of the ion that is being transported through a receptor activated channel? Have there been any experiments that were designed to accomplish this?

Posted: 12 May 2018 10:20 AM PDT

Can you accelerate "virtual objects" above c m/s?

Posted: 12 May 2018 11:25 AM PDT

Couldn't you theoretically make a virtual object e.g. a point on a screen faster than light speed and thus transfer information faster than c? Or imagine a laser pointing at a wall in great distance and the laser rotates at light speed, isn't the point then faster than light?

submitted by /u/shwarzee
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What affects the pH of water? (Sea water or normal)

Posted: 12 May 2018 01:03 PM PDT

Saturday, May 12, 2018

Why do ice cubes crack when liquid is poured over them?

Why do ice cubes crack when liquid is poured over them?


Why do ice cubes crack when liquid is poured over them?

Posted: 12 May 2018 03:56 AM PDT

Is there anything special about the visible spectrum that would have caused organisms to evolve to see it?

Posted: 12 May 2018 05:38 AM PDT

I hope that makes sense. I'm wondering if there is a known or possible reason that visible light is...well, visible to organisms and not other parts of the electromagnetic spectrum, or if the first organisms to evolve sight just happened to see in the visible wavelengths and it just perpetuated.

Not sure if this belonged in biology or physics but I guessed biology edit: I guessed wrong, it's more of a physics thing according to answers so far so I changed the flair for those who come after

submitted by /u/thestray
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Why does (what role) HIV infected children have higher prevalence of staphylococcus aureus than for other staphylococcus species?

Posted: 12 May 2018 05:39 AM PDT

Almost all studies on prevalence of staphylococcus among HIV children indicate higher prevalence for staphylococcus aureus than for other staphylococcus species. Why is this the case? What role does HIV infection play to contribute to this?

submitted by /u/opkyei
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Why does volcanic ash stay up for so long? Isn’t it relatively heavy?

Posted: 12 May 2018 02:19 AM PDT

Why does the first ionization energy go down from Nitrogen to Oxygen?

Posted: 12 May 2018 03:47 AM PDT

If the neutron does not possess any charge, how coud exists an antineutron?

Posted: 12 May 2018 03:20 AM PDT

I'm not physicist, but the intuitive concept of antimater that I have is that an antiparticle is just the same as the particle but with the oposite charge. Then, how can an antineutron exists and be detected?

submitted by /u/felmoltor
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Why can't we create a perfectly straight beam of light with optics? What makes lasers so special?

Posted: 12 May 2018 06:41 AM PDT

Just looking at the inside of camera lenses, it seems we know optics well enough to control light with a pretty high degree of precision. So, why is it that I've never seen light focused into a perfectly straight beam via glass lenses or mirrors before, and instead lasers beams have to be generated through special laser sources?

It seems like with our understanding of optics, it should be decently trivial to focus light onto a tiny spot then use a lense at that spot to straighten the beam out. Is there some inherent property with regular light that stops this from happening?

Edit: just to clarify, I understand that the waves on a laser beam are temporally and spatially coherent. I'd just like to know why it is that a beam of light that isn't coherent seemingly can't hold a straight beam.

submitted by /u/karlzhao314
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If a pregnant woman does not consume enough calcium during the babies development. Does her body choose to pull calcium from her own bones, or underdeveloped the bones of the child?

Posted: 11 May 2018 08:34 AM PDT

Is there a sort of priority for all of the babies development? Is the mother's own body a priority, or the childs? Mostly curious about the bones.

submitted by /u/PretendHumanoid
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Why are Copper(ii) compounds such as copper acetaf, bad for the Environment/people try to limit its exposure to the environment?

Posted: 12 May 2018 12:39 AM PDT

What would a CIE 1931 chromaticity diagram look like if it's normalized based on MacAdam ellipse?

Posted: 12 May 2018 03:39 AM PDT

Here is a standard CIE 1931 chromaticity diagram with MacAdam ellipse: https://en.wikipedia.org/wiki/Color_difference#/media/File:CIExy1931_MacAdam.png

You can see that the ellipses are not identical, with different shapes and sizes. That means the diagram is not isotropic on the basis of human perception. What if we modified the shape of the diagram, so that the MacAdam ellipses all become perfect circles with identical sizes. What would the diagram look like then?

submitted by /u/mteechan
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Does our native language effect the tone/ pitch of our voice?

Posted: 11 May 2018 09:29 AM PDT

I feel like I've had this preconceived notion that people with different native languages tend to have different pitched voices than others, as a trend. Like native German speakers have a deeper voice than native Italian speakers.

I'm not sure this is even true or not, but if it is, what causes it? Just the language itself and the way our mouth forms the different sounds needed to speak that language?

submitted by /u/hung-like-a-horsefly
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When a chemical "binds to my receptors" what is actually happening?

Posted: 11 May 2018 10:24 AM PDT

I have a liquid on me which is an irritant. My arms feel like they are burning/on fire, and wiki says the compound binds to the receptors which are responsible for the regulation of skin temperature, hence i assume, making the skin hot like its on fire.

A few hours later im fine, until I wash, then it gets re-activated, and i'm in the same pain as earlier. What is actually happening. Is the chemical compound sticking to cells and transforming them or something, and how does this even work?

submitted by /u/electricp0ww0w
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Why is the CMB cold spot more significant than other cold spots?

Posted: 11 May 2018 03:57 PM PDT

Looking at images of the CMB, I can see many cold regions of the universe. Some of them even appear larger than the one we know as "the cold spot". Are the colors visually misleading of the numbers they represent?

submitted by /u/nitemike
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Why are there moving shadows on the floor in front of my space heater?

Posted: 11 May 2018 04:36 PM PDT

Looking at the electric heater from above, there are moving shadows in front of it. The lighting comes from above. There is no smoke, so does the heat move, or bend, the light from above to concentrate it in some areas and remove it from others? Or, is it slowing the light down in some areas, something I'm pretty sure is impossible?

submitted by /u/spudzilla
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How is foreign DNA extracted from exhumed bodies?

Posted: 11 May 2018 07:19 PM PDT

I just read a thread where the killer was found on DNA evidence after the victim's body was exhumed over 20 years later.

How is foreign DNA, such as semen, able to survive within a rotting corpse for over 20 years and how is foreign DNA isolated and tested in that condition?

submitted by /u/countessmeemee
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Is there any liquid more thin then water?

Posted: 11 May 2018 12:00 PM PDT

In the 18th century, astronomers went around the globe to observe the transit of Venus knowing that if they compare their measurements, they could figure out how far the sun is. How does this work?

Posted: 11 May 2018 08:21 AM PDT

Does operating temperature actually affect a electronic device's performance?

Posted: 11 May 2018 04:10 PM PDT

Efficiency/reliability aside, does the temperature of a circuit make a meaningful impact? For example, would cooler processors work faster than hot ones? (Or vice versa?) Would this vary depending on the component?

submitted by /u/guacamoleman141
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Does Earth have Cryovolcanoes? If not, why?

Posted: 11 May 2018 11:30 AM PDT

Cryovolcanoes have been found on Enceladus, and there's evidence for them on many other moons like Titan and Triton. They're apparently pretty common in the solar system, and probably elsewhere.

Does Earth have any cryovolcanoes? We have geysers, but I'm not sure if these are the same thing since they have a different geological mechanism, and we don't call Earth's geysers "cryovolcanoes".

submitted by /u/StarlightDown
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What did the early (Vostok) cosmonauts carry with them when they returned to Earth?

Posted: 11 May 2018 10:09 AM PDT

There's all these online links with survival kits that cosmonauts carried after 1968 (the NAZ-3 survival kit), and the awesome TP-82 after 1982 for protection against wolves and bears in the wilderness, but what did the early Vostok cosmonauts (Gagarin, Titov etc) who landed without their capsule carry with them? In particular in terms of weapons, or any kind of survival kit for when they returned to Earth?

Did they typically land very far away from their capsule? Did the cosmonauts just wait for help or go to find people? How did the rescue teams find them? And how long did it usually take rescue teams to find them?

http://theappendix.net/posts/2013/11/the-cosmonauts-survival-kit

submitted by /u/its_a_science
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