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Monday, July 18, 2016

How did the first human ancestor with 23 chromosomes pairs breed with 24 chromosome apes?

How did the first human ancestor with 23 chromosomes pairs breed with 24 chromosome apes?


How did the first human ancestor with 23 chromosomes pairs breed with 24 chromosome apes?

Posted: 17 Jul 2016 09:52 PM PDT

Modern day humans have 23 pairs of chromosomes. Our ancestor apes must have had 24 pairs of chromosomes. Meaning that a mother with 24 chromosome gave birth to a 23 chromosome child. How did this 23 chromosome ape breed with its 24 chromosome pair species? Wouldn't their child have 47 chromosomes meaning its sterile? Edit: not anti-evolution, just curious Edit 2: thanks for the great responses guys! Gonna read all of them

submitted by /u/Stealth250
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Which organisms have a high ratio of mature mass to sperm+egg/seed/starting mass? Does this tell us anything useful?

Posted: 17 Jul 2016 12:12 PM PDT

For example, if a human egg and sperm are ~4ug, and the average adult mass is 70kg, then the ratio for humans is ~1.75*1010. If a giant sequoia seed is 50mg, and the average grown mass is 100,000kg, then the ratio for giant sequoias is ~2*109.

My intuition is that organisms that grow larger (i.e. blue whales) and organisms with smaller "starting" mass would have a higher ratio here. Is there any significance to this, or is it just a meaningless number?

submitted by /u/blake_n
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How much do tidal forces affect volcanic and magmatic activity?

Posted: 18 Jul 2016 07:34 AM PDT

For anything from Hawaii to Yellowstone, or even for similar things like oil deposits, how much does the tidal force from the moon affect them?

submitted by /u/jamiahx
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Is music finite?

Posted: 17 Jul 2016 05:43 PM PDT

Like, arrangements of songs, is it finite? If so has it/can the combinations be calculated?

submitted by /u/WelcomeToAnarchy99
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You are in the round space station from 2001: A Space Odyssey. What happens if you run with the stations spin?

Posted: 17 Jul 2016 10:08 PM PDT

What happens if you run opposite of the stations spin? Do you get lighter or heavier?

submitted by /u/fastovich1995
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Can a split brain hold a conversation?

Posted: 17 Jul 2016 08:34 PM PDT

When the two hemispheres of the brain are split both sides have limited control over the bodies movements. Since both sides can also see could you have a split brain person sit down and let the brain communicate with itself via a keyboard or shared piece of paper?(I am assuming that both side understand writing, if not could you use pictures?)

submitted by /u/AbnormalFillet
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are gravitational waves polarized?

Posted: 18 Jul 2016 07:36 AM PDT

I've read that gravitational waves are suspected to be made of gravitons that would be spin-2 and have either 2 or 5 spin states. I don't really understand all this so could someone simplify it for me?

submitted by /u/chunkylubber54
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How can we determine the curvature of the Universe while being inside of it?

Posted: 18 Jul 2016 02:22 AM PDT

To describe the curvature of the Universe, wouldn't we need an external reference frame to compare with or something?

That is, if I have a poorly drawn triangle, I can only tell it is poorly drawn because of the regular, external pixel grid that supports it. Now if the pixel grid had the same shape as the triangle, I wouldn't be able to tell if the triangle really is poorly drawn.

Another example would be if the Universe was a 2D sheet of paper. Now, if I curve the sheet of paper, nothing has changed inside of my 2D Universe: distances and triangles are the same, and the observer wouldn't notice anything different ; yet the Universe has curvature now, but in an external reference frame.


My point is, how can we tell if the Universe has curvature or not, if we happen to be in a Universe similar to my sheet of paper? observing that the Universe is flat does not disprove it has curvature elsewhere.

There are surely numerous properties I'm missing in my oversimplified model of Universe. I also feel that I'm not talking about the usual curvature.

submitted by /u/bread_god
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Why is the universe so big?

Posted: 17 Jul 2016 10:33 PM PDT

I know it sounds like a question a child would ask, but seriously. Is there any reason that there is so much stuff in the universe and it's so spread out?

submitted by /u/SillyFlyGuy
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If I double the mass of explosives (from 50kg to 100kg), does it double the size of the explosion?

Posted: 18 Jul 2016 02:32 AM PDT

If I had a warhead that contained 50kg of explosives and has a blast radius of 100m, would doubling the explosives content result in a linear increase of the blast radius? I need to characterize the difference in blast radius between two weapon systems, but this is not my area of expertise. Thank you for your help!

submitted by /u/TOBronyITArmy
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For two objects 50 billion light years away from each other, can it be said that anything happens on them simultaneously? Is there "simultaneousness" even with time dilation, etc?

Posted: 17 Jul 2016 07:35 PM PDT

[Human Body] Are the parts of our body most sensitive to pleasure also the most sensitive to pain, and vice versa?

Posted: 17 Jul 2016 09:15 AM PDT

Is there a relationship between Chaos Theory and Quantum Physics?

Posted: 18 Jul 2016 07:06 AM PDT

Inspired by this post.

submitted by /u/QUEestioNinator
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Why doesn't scuba gear make you breathe the same air twice?

Posted: 17 Jul 2016 08:22 PM PDT

Yes I'm familiar with rebreathers but I'm not talking about that. I'm also aware of CO2 buildup and O2 depletion, but if you breathe the air you just exhaled only one more time, it shouldn't be a problem. There is still some oxygen left in your exhaled air and there isn't that much CO2 in it. If you reuse the air in your lungs just once, I think you can extend your dive by 30 or 40 percent.

submitted by /u/bryceguy72
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How does alcohol poisoning happen?

Posted: 17 Jul 2016 09:26 PM PDT

Usually doesn't your body just make you throw up anymore alcohol you drink if you can't process any more? How do people digest so much alcohol without throwing up that they can get alcohol poisoning from it?

submitted by /u/WobblyHobbly
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I listen to podcasts at 1.3x speed but only notice it when the intro /outro music comes on. What is my brain doing that causes this to happen?

Posted: 17 Jul 2016 01:05 PM PDT

How fast do the eyes move?

Posted: 17 Jul 2016 04:47 PM PDT

Do all cosmic strings have the same mass density?

Posted: 17 Jul 2016 06:40 PM PDT

Wikipedia states that a cosmic string one kilometer in length would have about the mass of Earth. I am wondering though, is this the same for all cosmic strings or is the actual linear density of a cosmic string dependent on other factors?

submitted by /u/MookVanguard
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Why do Namib Ants don't hunt in the afternoon/dark?

Posted: 17 Jul 2016 10:14 PM PDT

I was watching the documentary "The Hunt" (bbc) and on one of the episodes (s1e5) they show ants in the namib habitat. They talk about how they have to keep moving in order not to die from overheating, but I didn't understand why is it that they don't hunt in the afternoon or at night, where the temperatures are lower?

EDIT: Is this considered Earth Science or Biology?

submitted by /u/remi1771
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At what pressure does touch become pain?

Posted: 18 Jul 2016 03:11 AM PDT

Does Juno experience any time dilation due to its proximity to Jupiter?

Posted: 17 Jul 2016 04:14 PM PDT

Jupiter is the most massive object in our solar system aside from the sun. Does Juno experience any time dilation from being in such close proximity to it?

submitted by /u/86smopuiM
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How far back it is possible to say how many days have passed precisely since a given date before introduction of contemporary calendars? In the same vein, have all weeks since, say 900 AD, been kept continuous until today?

Posted: 17 Jul 2016 12:33 PM PDT

Do we know how many days old would Thomas Aquinas be and if he died on a Tuesday?

submitted by /u/ubertrashcat
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Sunday, July 17, 2016

Does the weightlessness in space have an affect on blood circulation in astronauts?

Does the weightlessness in space have an affect on blood circulation in astronauts?


Does the weightlessness in space have an affect on blood circulation in astronauts?

Posted: 16 Jul 2016 05:12 PM PDT

For example, if you (in relation to the earth) hung upside down would you feel the blood rush to your head like you do on Earth? Does the Earth's gravitational pull still effect you? Perhaps just less? Thanks for any answers!

submitted by /u/SmallManBigMouth
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Is The Universe Cooling Faster than it Expands?

Posted: 16 Jul 2016 06:33 PM PDT

... is there a direct relationship between temperature and the potential complexity of system (universe)?

submitted by /u/jesusgottajones
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Why isn't the mosquito an intermediate host for HIV/AIDS? Can it be?

Posted: 16 Jul 2016 03:06 PM PDT

I am reading In Praise of Wolves by R.D. Lawrence and I just learned mosquitos are an intermediate host for Dirofilaria imitis (common dog heartworm) as well as malaria and encephalitis. How does the mosquito transfer the disease? Is it through blood contact? If so, is it theoretically possible to contract HIV/AIDS from a mosquito bite if he is carrying the pathogen?

submitted by /u/vogue_ish
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Can our brain know what time it is while we're asleep?

Posted: 16 Jul 2016 02:46 PM PDT

Is our biological clock aware of the solar clock?

submitted by /u/AyFamWasGoodBruh
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How can a transistor amplifier have a low input or output resistance? Like with a Common Base setup?

Posted: 17 Jul 2016 05:14 AM PDT

Judging from the hybrid pi model, any connection between transistor terminals is always characterised by a high resistance (r_pi and r_o)... does that mean I can not use this model for CB? Or am I doing something wrong?

submitted by /u/Tyssy
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Two objects leave Earth at the same time for Alpha Centauri 4,37 lightyears away. The other object travels at 99,9% speed of light, and the other at 10% c. Considering time dilation, how far apart in time do they arrive?

Posted: 17 Jul 2016 05:13 AM PDT

Under what circumstances is the difference between "microgravity" and "weightlessness" significant?

Posted: 17 Jul 2016 08:16 AM PDT

There seems to be a significant push to stop referring to astronauts and other low earth orbit situations as being "weightless", but instead correct it to "microgravity". It seems fairly nitpicky, and I can't imagine it's terribly relevant. How am I mistaken?

submitted by /u/N8CCRG
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How does the skin on your finger heal so that your fingerprint doesn't change?

Posted: 16 Jul 2016 12:26 PM PDT

A few weeks ago I cut my index finger while slicing some vegetables. After the cut healed, I saw that there wasn't any visible change to my fingerprint. The cut seemed pretty deep so I was surprised by this, hence me asking the question here.

submitted by /u/Senor_Mouse
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How to scientists determine enthalpies of fusion of salts?

Posted: 17 Jul 2016 07:53 AM PDT

Doesn't seem like it's possible to account for heat absorbed and emitted at the same time.

submitted by /u/dankscene
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Is it possible for a new planet to form in our solar system?

Posted: 17 Jul 2016 07:47 AM PDT

Star to Planet?

Posted: 17 Jul 2016 07:10 AM PDT

I'm curious. I read somewhere that gas giants, if large enough, could eventually collapse into a small star. I want to know if the reverse can happen and a step further. Can a star lose mass somehow, become a gas giant and then condense into a terrestrial planet?

Edit: And what would it look like if it could exist?

submitted by /u/TimmyBrockz
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Is the arc of a rainbow consistent for all rainbows?

Posted: 16 Jul 2016 04:29 PM PDT

Curious if they are consistent throughout nature.

submitted by /u/Snellington
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Is there a theoretical limit to the melting point of a material?

Posted: 16 Jul 2016 01:14 PM PDT

Effects of electrons in high energy orbitals on molecular characteristics?

Posted: 16 Jul 2016 09:25 PM PDT

The effects of electrons transitioning from lower to higher energy electron orbitals and vice versa are quite well understood, expressing as Fluorescence, Phosphorescence etc.

But i would like to understand how changes in the arrangement of electrons from high or low energy states within molecules like water affects the physical characteristics of the molecule?

I know in Phosphorescence it's accepted that the electrons return to their lowest energy state, but if not enough energy is captured to release a photon then the gained energy must remain stored, which should have effects.

Surely if an electron has more energy it must effect the polar bonding forces, which should effect the density?

Focusing on water, what effects would high energy electron states have on water as a solvent?

submitted by /u/Cropdog
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Why do we need to carry fuel in space, doesn't the rocket/spacecraft keep traveling in a straight line with a constant velocity from the point it leaves our orbit?

Posted: 16 Jul 2016 07:53 PM PDT

From what I understand, objects in space move in a straight line with the velocity it was given until it was interrupted by another force (Newton's first law). So technically, we only need fuel to achieve escape velocity right? And keep traveling forever?

Does the gravity of all the planets and bodies in solar system interfere with this somehow?

Edit: When I meant fuel, I was talking about propulsion fuel. I'm aware that the rocket/spacecraft still needs fuel to maneuver about in space.

submitted by /u/Kyrie01010011
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What causes a space shuttle to heat up on reentry into earth's atmosphere?

Posted: 17 Jul 2016 04:10 AM PDT

Many articles online point to friction, but then I see countless comments explaining that friction only heavily affects the shuttle at low altitudes. I also recently saw a QI episode which immediately ruled out friction as an explanation of a the heat and explained it as bow shock similar to bow shock waves which affect ships in the sea, a sort of build up of pressure. Any more information would be great.

submitted by /u/Wert3a
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How are caves formed?

Posted: 16 Jul 2016 11:18 AM PDT

I was thinking about caves and began to wonder how exactly they are formed. I presume that erosion plays a big part in the process, but how would that start in the first place? And where would that water go? And what about sealed off caves with no cave opening?

submitted by /u/ThisIanGuy
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Can you make artificial gravity in a sphere?

Posted: 16 Jul 2016 06:02 PM PDT

I know about the artificial gravity that can be achieved by rotating a spaceship via centrifugal force(that's the right one right?). But that, as far as I know, only works in a circular pattern. Is it possible that a sphere, instead of a torus, can spin in such a way that it would produce artificial gravity in every direction on the inside of said sphere(basically like an inverted planet)?

submitted by /u/bagelbomb
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Are there alternative treatments to antibiotic resistant infections?

Posted: 16 Jul 2016 12:38 PM PDT

Recently, there have been a slew of articles about bacteria that are now resistant to our antibiotics of last resort. Apparently, gonorrhea will be the first to cross the finish line. Barring the discovery of new more potent antibiotics, what will medicine do to fight these antibiotic resistant infections?

submitted by /u/EcksrayYangkeyZooloo
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If 100g of lean chicken breast provides about 26g of protein and 1g of fat, what happens to the other 73g of mass?

Posted: 16 Jul 2016 11:18 AM PDT

Why does thoriated glass develop a yellow tint over time?

Posted: 16 Jul 2016 09:59 PM PDT

Some time ago radioactive thorium was used to create glass with high refractive indices for use in the lens making industry. It has been largely replaced now (due to the health issues associated with radioisotopes) but examples of this original glass have become yellowed over time. Some people suggest that exposing the glass to UV light will return it to a clear state. What is going on here?

submitted by /u/bostwickenator
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How do we not retain memories as a baby? Why do our earliest memories start around 2?

Posted: 16 Jul 2016 09:56 AM PDT

Which star has moved the most in human history?

Posted: 16 Jul 2016 09:05 PM PDT

Which of the stars in the night sky has (appeared to have) moved the most in the recent past and in all of human history? I know stars are used for navigation because of their location in the sky but they are moving, just imperceptible slowly. Which ones can we, either in ones lifetime or in human history, can we perceive the movement?

submitted by /u/nygiant3
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Saturday, July 16, 2016

Do the holes on a dice which represent the numbers affect the chances of getting different numbers?

Do the holes on a dice which represent the numbers affect the chances of getting different numbers?


Do the holes on a dice which represent the numbers affect the chances of getting different numbers?

Posted: 16 Jul 2016 07:05 AM PDT

6 holes for number 6, 5 for 5 and so on. Dont these holes make the dice non symmetric and make the air affects it in different ways? also why manufacturers dont paint numbers instead of holes?

submitted by /u/Forenkazan
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Why is the nozzle on a rocket engine designed to reduce the gas pressure to the external pressure ? How is it more efficient ?

Posted: 16 Jul 2016 06:06 AM PDT

I've been learning on my own how rocket engines works (well approximately), and I've understood the part about the third law of motion and conservation of momentum. But I don't understand the pressure related aspect of such engines. I've seen that depending on what altitude you mean to use it, you have to elongate the nozzle so that the pressure reduces as much as possible until at the end of the nozzle, it is equal to the external pressure. But I would think that to increase the speed of the exhaust gas, one would need high pressure gas so that it wants to go even faster out of the engine ?

Also I don't really understand the need for pressurizing the gas before the combustion chamber : is it to help combustion ? To reduce the size/weight of the combustion chamber ?

Thanks if you answer !

submitted by /u/Adjac
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How quickly would dominoes fall in stronger or weaker gravity?

Posted: 16 Jul 2016 06:39 AM PDT

If two particles are entangled, and I measure the momentum on one while simultaneously measuring the position of the second particle, wont I now know both the position and momentum of the second particle at the same time, violating the principle of complementarity?

Posted: 15 Jul 2016 10:36 PM PDT

I was just reading on quantum entanglement and this came to my mind, and I couldn't think of any solution.

submitted by /u/coolamebe
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Could you answer a few questions about neutron stars?

Posted: 15 Jul 2016 04:12 PM PDT

1) What would happen if you removed say 99% of the matter that makes up a neutron star? would the remaining matter fly apart into protons, electrons etc as its held together by the fierce gravitiy of the whole neutron star?

2) If two neutron stars collided would bits of them be blown off or would it all be held by the gravity of the two objects? is there a non-zero chance that 'neutron star bits and pieces' could impact the earth? also would the two just form a black hole?

3) if a neutron star began accreting matter from a 'regular' star (in a binary system or something) would the matter undergo nuclear fusion like in a regular star? Thanks, feel free to answer one, all, or none of the above

submitted by /u/maxjnorman
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Can you measure mass without acceleration?

Posted: 16 Jul 2016 05:16 AM PDT

A kilogram is a measure of mass. On earth we weigh it with a scale, and in space we might try to accelerate an object and see how much force it takes. If for whatever reason we couldn't accelerate it, is there a way to measure it's mass?

Also, now that I think about it, does this mean a person would technically be however many kilograms on earth or Mars, because if the definition?

submitted by /u/generic53688
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Is the total angular momentum of all bodies in the universe conserved as a whole?

Posted: 15 Jul 2016 08:55 AM PDT

Why can transistors be so small, but resistors capacitors and other components are comparatively large?

Posted: 15 Jul 2016 09:16 AM PDT

If I'm traveling *very* fast and I hit a photon, will it hit me like a higher energy photon?

Posted: 15 Jul 2016 05:34 PM PDT

To restate the question, if I'm traveling at a significant fraction of the speed of light and I encounter a photon of non-ionizing radiation head-on, will the Doppler effect make it appear to me like ionizing radiation? Like an extreme blue shift?

submitted by /u/Cashfloe
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What's the (theoretical?) limit of the compression of matter? More on comments

Posted: 15 Jul 2016 12:32 PM PDT

What keeps it from happening? Do black holes reach that point? If so, how could matter be compressed in a "single point" just before the Big Bang and still contain the matter that makes black holes and everything else? Was it gravity that kept it all together before the Big Bang? Am I feeling a bit too relativistic today?

submitted by /u/disintegrationist
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Is there any evidence that automated/touchless public bathrooms actually reduce the spread of disease?

Posted: 15 Jul 2016 10:55 AM PDT

Not reduce the spread of germs. Just because a person picked up bacteria doesn't mean they got ill from it.

And especially in light of the fact that many bathrooms only have some touchless features, and almost none have automatic doors.

ETA: I imagine a nice study would be if a workplace upgraded their bathrooms and then looked to see if employees took fewer sick days afterwards. Because in a more public space it would be much more difficult to track whether people got sick or not.

submitted by /u/random_number_string
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Does global warming affect geology?

Posted: 15 Jul 2016 08:03 PM PDT

I watch a decent amount of documentary shows including things that talk about various points in prehistory.

With the earth having gone through greater geological activity in the past, does that mean that as the temperature continues to rise, earthquakes and such will be more frequent?

I could imagine the greater energy at an atomic level resulting in more active tectonic plates, but it's never discussed in any shows.

submitted by /u/Tylerdurdon
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Is The Mass of The Universe Constant?

Posted: 15 Jul 2016 09:04 AM PDT

If not, how can it be gained/lost?

submitted by /u/184758249
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Does the equipartition theorem apply to a guitar string?

Posted: 15 Jul 2016 01:31 PM PDT

I just read about the equipartition theorem, stating that for a system at equilibrium energy is equally shared among its possible forms. For a harmonic oscillator, I'm making an assumption that it would mean each overtone should have an equal amount of energy associated with it.

If a finite amount of elastic potential energy is given to a string, and this energy is shared equally among an infinite number of overtones, does this mean each overtone has effectively zero energy associated with it?

submitted by /u/Dieneforpi
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Does gravity affect the measurement of time or the actual passage of time itself?

Posted: 15 Jul 2016 08:40 AM PDT

There's are two cars on Earth that are placed on treadmills. They both accelerate to the same speed and hold the speed indefinitely. One of the treadmills is then transported to Jupiter. Assume all environmental parameters between the two sites are the same, same car/air density/etc. Let's also assume communication between the two cars are instantaneous. Once the treadmill lands on Jupiter, both treadmills are stopped and the cars shoot out at whatever speed they were traveling at prior. After 1 hour as measured on earth, both cars are instructed to stop immediately. Has the car on Jupiter gone a different distance because time passes at a different rate or that its speed was different as time was measured at a different rate.

submitted by /u/PM_ME_YOUR_WET_SPOT
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How can you figure out the rotational spin of a planet in other system?

Posted: 15 Jul 2016 12:39 PM PDT

I remember being told about a method by a Phd Student at Exeter Uni how they used the Doppler shifted light of the planet. But I didn't really understand. Can someone explain to me how and other methods are used?

submitted by /u/letlightning
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All objects in a black hole reach the singularity in finite time, yet the singularity is not within spacetime and is infinitely far from the event horizon. How does something travel infinite distance in finite time?

Posted: 15 Jul 2016 10:58 AM PDT

Where am I wrong? I'm guessing saying the singularity is infinitely far from the event horizon is wrong in some way, but I've heard it is not contained in the topography of spacetime and is essentially infinite in distance.

submitted by /u/FatalPaperCut
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Why does nitric acid digestion work better when diluted?

Posted: 15 Jul 2016 10:25 AM PDT

Okay so i work with acid digestion of doree beads. The beads contain only silver and gold. We did a small experiment where we use concentrated nitric acid on pure silver to see if it would digestion. Nothing happened, we then added water to the acid and the digestion began to happen. We normaly use 50% v/v nitric for digestions. I'm curious as to why the concentrated nitric acid wont digest the silver. Thanks for any and all help

submitted by /u/WowoTabernak
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