Why is the answer for Earth's Schwarzschild radius: the volume Earth would have to be compressed in order to form a black hole, exactly the same when derived either from Newtonian mechanics or General Relativity ?

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• Why is the answer for Earth's Schwarzschild radius: the volume Earth would have to be compressed in order to form a black hole, exactly the same when derived either from Newtonian mechanics or General Relativity ?
• Why do we use Sodium for street lighting ?
• If I transported a flock of birds to the southern hemisphere, would they fly north for the winter or head further south when it starts getting cold?
• What is the absolute fastest that sound can travel, and in what medium can it obtain that speed?
• If there was a giant ring of steel with a radius one foot greater than the Earth's radius placed around Earth, would it seemingly levitate one foot off the ground?
• Could a near-light-speed spacecraft travel in a loop, or only in straight lines?
• Do we experience less gravity during day time, because of the pull from the sun counteracting Earth's gravity? How big is this effect?
• Is there any evidence that Uranus's axis is slowly "correcting" itself to be in line with the other planets' axes?
• How do isolated populations of animals keep from getting inbred?
• Is it possible to write an equation for eccentric anomaly of an elliptical orbit in terms of time?
• As the universe continues to expand, is it "seeding" (for lack of a better term) matter behind its boundary or only expanding empty space?
• Packing: Rolling vs Folding. Is there even a difference?
• Is the amount of oxygen in the air in/arround a big city noticable lower than in small cities or rural areas?
• When I hear a sonic boom, am I hearing all the sound generated by the speeding projectile over a certain distance all in one go?
• Heard that we tend to like people who look like ourselves more. Is it about how we actually look, or how we think we look?
• What's the difference between d^2 x(t)/dt^2 = -x(t), and idx/dt=-x(t)?
• Why doesn't the black hole at the center of the galaxy cosumes the galaxy itself?
• Why are large primes so desirable and hard to calculate?

Why is the answer for Earth's Schwarzschild radius: the volume Earth would have to be compressed in order to form a black hole, exactly the same when derived either from Newtonian mechanics or General Relativity ? Posted: 06 May 2016 09:23 PM PDT I saw this post and someone did a mathematical calculation for the radius : The formula for escape velocity is Vesc = sqrt(2GM/R) where G is the gravitational constant, M is the mass (of the Earth, in this case) and R is the radius in question. If we plug c (speed of light) in as Vesc, G = 6.67408 × 10-11 m3 kg-1 s-2, and M = 5.972 × 1024 kg, we can solve for R. R = 0.8870 cm Someone else later mentioned that : The funny thing is that what you did is the classical Newtonian gravity calculation, but in a universe where Einstein's General Relativity is in effect there is no reason to expect that calculation to actually be true. It took tons of work after GR was discovered before Schwarzschild managed to do the calculation and figure this out (Einstein couldn't do it)... and the answer was exactly the same. I want to know why? Was the general approximation in Newtonian physics relevant here or was there some other reason ? submitted by /u/p-p-paper [link] [comments]

Why do we use Sodium for street lighting ? Posted: 05 May 2016 03:25 PM PDT Hi redditors ! Ok so coming back home today I had a thought I have frequently about how sodium is used in street lighting -at least the orange ones- and I wondered, why did we use sodium specifically ? I know about how every atoms has its own emission spectrum -and absorption- and that sodium has a double spectral line around 589nm, which is in the 'orange part' of the visible spectrum, but I was wondering, why did we pick sodium and orange lightning specifically. Was it for economical reasons ? Because Orange was a better choice for a reason I don't really get ? Thanks in advance for answering ! Edit: Thanks for the answers guys ! That's almost what I thought but the reflection on the impact on astronomy is really interesting ! submitted by /u/ThatSlowBerry [link] [comments]

If I transported a flock of birds to the southern hemisphere, would they fly north for the winter or head further south when it starts getting cold? Posted: 06 May 2016 07:34 AM PDT Thus dooming themselves. submitted by /u/1jl [link] [comments]

What is the absolute fastest that sound can travel, and in what medium can it obtain that speed? Posted: 06 May 2016 12:29 PM PDT submitted by /u/efficiens [link] [comments]

If there was a giant ring of steel with a radius one foot greater than the Earth's radius placed around Earth, would it seemingly levitate one foot off the ground? Posted: 06 May 2016 08:39 AM PDT Let's just assume that the Earth is perfectly round in this situation, and the steel is unbendable and indestructible. Would it appear to float? Why or why not? What if the steel wasn't unbendable/indestructible? submitted by /u/TheAlmightyLem [link] [comments]

Could a near-light-speed spacecraft travel in a loop, or only in straight lines? Posted: 06 May 2016 08:53 AM PDT Lets say I have a spaceship that is capable of accelerating to near light speed (and it takes a while to get going that fast), and I want to use it to experience time dilation and come back to Earth far in the future. Is the only real option to accelerate in a straight line, then come to a stop, turn around, and come back in another straight line? To me this is not ideal because you have to go through two acceleration/deceleration cycles, so the time dilation effect relative to Earth would be lessened. So, could it be possible / practical for the spacecraft to travel in a loop, by continuously adjusting its direction of thrust until it travels in a complete circle? Intuitively I think that this would not be possible at near-light speeds, but my intuitive sense of the physics here is not too strong. Would be very interested to hear what equations or theorems are relevant here :) Thanks in advance for any responses! submitted by /u/Fosforus [link] [comments]

Do we experience less gravity during day time, because of the pull from the sun counteracting Earth's gravity? How big is this effect? Posted: 06 May 2016 07:35 AM PDT submitted by /u/lucaspon [link] [comments]

Is there any evidence that Uranus's axis is slowly "correcting" itself to be in line with the other planets' axes? Posted: 06 May 2016 09:50 AM PDT submitted by /u/sonorousAssailant [link] [comments]

How do isolated populations of animals keep from getting inbred? Posted: 06 May 2016 07:24 AM PDT What made me think of this was my run today. I live near a pond, and there is a small family of muskrats in it. I'd say 5 or so at most. Now, there aren't any other ponds or anything for several miles around, so I'm wondering what these populations do. Do they travel back and forth? Do they breed with siblings and parents? How do different types of animals handle this situation? submitted by /u/RPShep [link] [comments]

Is it possible to write an equation for eccentric anomaly of an elliptical orbit in terms of time? Posted: 06 May 2016 09:01 AM PDT I know you can get the mean anomaly in terms of time for an elliptical orbit, but is it possible to get the eccentric anomaly in terms of time? submitted by /u/Jmaster414 [link] [comments]

As the universe continues to expand, is it "seeding" (for lack of a better term) matter behind its boundary or only expanding empty space? Posted: 06 May 2016 07:35 AM PDT Put differently, is all the matter there ever will be already "in play," or is some of it still being carried by the expansion wave of the universe? Edit: to be clear, I'm talking about something like debris riding a shockwave, not spontaneous creation of matter submitted by /u/dunaan [link] [comments]

Packing: Rolling vs Folding. Is there even a difference? Posted: 06 May 2016 02:22 AM PDT I'm packing in a few hours and I should have asked this in advance. Anyway, does it even make a difference? I'm thinking that however you fold the cloth, the size it takes will be about the same. And people are just exaggerating. I guess the question is more like, which method compresses the cloth better without the use of a sealed container and a vacuum? I believe that's the real question since people who are debating about which method to use are concerned about fitting more stuff. Also ignore the difference in which rolling will occupy the bag more (imagine solid vs liquid in a container). I say to ignore because even with folding you can use your socks to fill in the gaps. Or just roll some to fill the gaps. submitted by /u/PullIntestinesFrmAss [link] [comments]

Is the amount of oxygen in the air in/arround a big city noticable lower than in small cities or rural areas? Posted: 06 May 2016 07:59 AM PDT submitted by /u/Pidiotpong [link] [comments]

When I hear a sonic boom, am I hearing all the sound generated by the speeding projectile over a certain distance all in one go? Posted: 06 May 2016 05:22 AM PDT This is how I interpret this diagram of a mach cone if we place ourselves at the red dot, but I haven't yet (after some brief internet searching) found anywhere that explains it this way. Mach cone submitted by /u/BedSideCabinet [link] [comments]

Heard that we tend to like people who look like ourselves more. Is it about how we actually look, or how we think we look? Posted: 06 May 2016 02:47 AM PDT submitted by /u/singed1337 [link] [comments]

What's the difference between d^2 x(t)/dt^2 = -x(t), and idx/dt=-x(t)? Posted: 06 May 2016 05:57 AM PDT In this specific case, it's only true when d2 x(t)/dt2 =idx/dt, but is there a more general connection? The two equations give the same solution set. submitted by /u/Urist_was_taken [link] [comments]

Why doesn't the black hole at the center of the galaxy cosumes the galaxy itself? Posted: 06 May 2016 03:47 AM PDT submitted by /u/Bpbegha [link] [comments]

Why are large primes so desirable and hard to calculate? Posted: 06 May 2016 04:28 AM PDT Follow-Up: Why can't a formula like (10n ) +1 be used to find a prime of the desired length? submitted by /u/Kaingon [link] [comments]

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We are paleontologists who study fossils from an incredible site in Texas called the Arlington Archosaur Site. Ask us anything!

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• We are paleontologists who study fossils from an incredible site in Texas called the Arlington Archosaur Site. Ask us anything!
• Gravity and time dilation?
• When calculating flight paths for potential interstellar crafts, are dark matter & energy factored into equations?
• Why are some vaccines combined?
• Do Kepler's laws still hold in general relativity?
• Do you use your abdominal muscles when you sneeze? if so, does it make any significant difference over time for people who tend to do it more often than others?
• Are OLEDs "alive"? To me, organic means living.
• What could potentially ignite when exposed to oxygen?
• In space gravity is recreated by using g-force which holds objects outwards like the gravatron at the fair, how come we cannot artificially create gravity in which the force is inwards like on earth?
• What is that wet thing at the end of a plucked hair called?
• What determines how long a day cycle is on a planet?
• How does quicksand form and how dangerous is it?
• For the ideal rocket equation, what does the area under the curve represent?
• [Earth Science] If another 7.9 or larger earthquake came from the San Andreas fault, could seismographs along the New Madrid fault register the disturbance as well?
• Why does the temperature of the thermosphere increase as altitude increases whilst the temperature of the mesosphere decreases?
• I hit my elbow to an metallic container at work and the nerve"shock" i got went from my elbow, inside my arm and ended in my pinky finger. It was like a string inside getting electrocuted. What actually happened?

We are paleontologists who study fossils from an incredible site in Texas called the Arlington Archosaur Site. Ask us anything! Posted: 06 May 2016 05:54 AM PDT Hi Reddit, we are paleontologists Chris Noto and Stephanie Drumheller-Horton. From Dr. Noto: I been fascinated by ancient life for as long as I can remember. At heart I am a paleoecologist, interested in fossil organisms as once living things inhabiting and interacting with each other and their environment. Currently I am an assistant professor in Biological Sciences at the University of Wisconsin-Parkside. From Dr. Drumheller-Horton: My research falls into two broad fields: taphonomy (the study of everything that happens to an organism from when it dies until when we find it) and crocodylian evolution/behavior. I am an assistant adjunct professor and lecturer in Earth and Planetary Sciences at the University of Tennessee. Texas was a very different place 95 million years ago. Dinosaurs and crocodiles dominated a lush coast, preserved as a rich fossil bed in Dallas-Forth Worth called the Arlington Archosaur Site (AAS). The AAS is an important, productive fossil locality that preserves a previously unknown fauna from this part of North America. The rocks here contain a rare record of ecosystem transition, when major groups of dinosaurs and other animals were changing significantly. The AAS preserves a nearly complete coastal ecosystem, providing an unparalleled glimpse into the life that existed here over 95 million years ago. Thousands of specimens have been recovered including previously unknown dinosaurs, crocodiles, turtles, mammals, amphibians, fish, invertebrates, and plants. The diversity, abundance, and quality of the material is extraordinary. The site is run in partnership with amateur volunteers, creating a unique citizen-science initiative with far-reaching education opportunities for the surrounding community. You can find us on Facebook here! We will be back at 1:30ET to answer your questions. Ask us anything! submitted by /u/ArlingtonArchosaurs [link] [comments]

Gravity and time dilation? Posted: 05 May 2016 10:15 AM PDT The closer you are to a massive body in space, the slower times goes to you relative to someone further away. What if you where an equal distance in between two massive bodies of equal size so the gravity cancels out. would time still travel slower for you relative to someone further away? submitted by /u/DownFalldotcom [link] [comments]

When calculating flight paths for potential interstellar crafts, are dark matter & energy factored into equations? Posted: 05 May 2016 02:48 PM PDT Or do the formulas behind relativity already incorporate these forces? Would dark matter/energy come into effect if we stay within our galaxy cluster, or are these forces only noticed on the largest of scales? submitted by /u/PredatorRedditer [link] [comments]

Why are some vaccines combined? Posted: 05 May 2016 11:16 AM PDT Certain vaccines are combined with others into one. For example: MMR (measles, mumps, and rubella), and Tdap (tetanus, diphtheria, and acellular pertussis). Are they more related to each other molecularly? How is it decided which ones get mixed together? submitted by /u/frc_swag [link] [comments]

Do Kepler's laws still hold in general relativity? Posted: 05 May 2016 07:39 AM PDT Newton's inverse square law was shown to be not quite accurate in describing planetary motion. Do some or all of Kepler's three laws of planetary motion hold up against general relativity? submitted by /u/ienjoyapples [link] [comments]

Do you use your abdominal muscles when you sneeze? if so, does it make any significant difference over time for people who tend to do it more often than others? Posted: 05 May 2016 01:00 PM PDT submitted by /u/Skyices [link] [comments]

Are OLEDs "alive"? To me, organic means living. Posted: 06 May 2016 06:14 AM PDT To me, something organic is or was alive, like a plant or a cell. Are oleds made from living cells or is my understanding of the word "organic" not broad enough? submitted by /u/oodelay [link] [comments]

What could potentially ignite when exposed to oxygen? Posted: 05 May 2016 02:57 PM PDT Sorry, stupid screen-writer here... I've got a booby trap I'm trying to explain with real science. A chamber, sealed for years, is finally opened... but upon breaching it, I wish for it to explode. Is there any such thing in the logic of science that could do this? Or should I just use my creative license? Thanks! submitted by /u/TheSasquatchKing [link] [comments]

In space gravity is recreated by using g-force which holds objects outwards like the gravatron at the fair, how come we cannot artificially create gravity in which the force is inwards like on earth? Posted: 05 May 2016 07:01 AM PDT submitted by /u/AELYUS_FPV [link] [comments]

What is that wet thing at the end of a plucked hair called? Posted: 05 May 2016 10:47 AM PDT I know the title might not be as descriptive as you'd like, but I have no other way to describe it without using more words than what would be acceptable for a title.. I have noticed whenever I pluck a hair, there would often be a soft, wet ''thing'' at the end of the hair that was pulled out. It's the same color as the hair that was plucked. What's more is if you take a piece of white paper and wipe the ''thing'' on it, it dissolves and leaves a mark on the paper. The mark is the exact some color as the hair. I have tested this on several people with different hair colors and the results are the same. Not every hair has it. I've noticed they are more prevalent on thicker hairs than thin ones. Does anyone know what this is? submitted by /u/RzadMMY90 [link] [comments]

What determines how long a day cycle is on a planet? Posted: 05 May 2016 02:48 PM PDT Example: Earth's rotational period is 23 hours 56 minutes. Jupiter is 9 hours 55 minutes. Neptune is 16 hours 6 minutes. I thought rotational periods were relative to their distance from the sun. Well Earth is closer to the sun than Jupiter and earth has a longer day cycle, and Neptune is farther from the sun than Jupiter but Neptune has a longer day cycle. Does distance from the sun not determine how it takes a planet to rotate? submitted by /u/Adamsandlersshorts [link] [comments]

How does quicksand form and how dangerous is it? Posted: 05 May 2016 05:48 PM PDT submitted by /u/devilsrevolver [link] [comments]

For the ideal rocket equation, what does the area under the curve represent? Posted: 05 May 2016 06:02 PM PDT During my wikipedia adventures I came across the ideal rocket equation, and I love this kind of stuff. I was reading through the page and it had no mention of area under the graph - IIRC the area under the curve is relevant to a related property, but I don't know what this would be for the mass ratio x velocity. I tried googling, no answers there. Thanks! submitted by /u/DarkAvenger225 [link] [comments]

[Earth Science] If another 7.9 or larger earthquake came from the San Andreas fault, could seismographs along the New Madrid fault register the disturbance as well? Posted: 05 May 2016 10:21 AM PDT Follow up question. Could a severe earthquake from the San Andreas fault cause some kind of chain reaction of sorts from faults around the globe? submitted by /u/Fubarfrank [link] [comments]

Why does the temperature of the thermosphere increase as altitude increases whilst the temperature of the mesosphere decreases? Posted: 05 May 2016 06:31 AM PDT submitted by /u/PainIntoPower [link] [comments]

I hit my elbow to an metallic container at work and the nerve"shock" i got went from my elbow, inside my arm and ended in my pinky finger. It was like a string inside getting electrocuted. What actually happened? Posted: 05 May 2016 05:48 AM PDT submitted by /u/JebbeK [link] [comments]

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Did relativity HAVE to be discovered mathematically? Could we have discovered the exact equations empirically? Say from observing the difference in clocks on the ground vs on satellites

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• Did relativity HAVE to be discovered mathematically? Could we have discovered the exact equations empirically? Say from observing the difference in clocks on the ground vs on satellites
• What would happen if you were struck by a tic tac traveling ~1% the speed of light?
• Why aren't there pure ATP supplements available on the market as energy boosters? What would happen if you took these?
• Many people argue that First-Past-the-Post voting system is the worst. Arrow's theorem says that there is no perfect voting system. Is there a way to mathematically quantify the utility of a voting system, and if there is, then which one comes out on top?
• After watching a video flyover of Titan, I wondered how scientists delineate one pole as "north" and the other as "south" on non-earth bodies? Magnetism? Alignment with the solar plane? Other?
• If sucrose has a lower enthalpy of combustion than octane, why can't we / don't we use it as a fuel?
• Is ethanol the only alcohol that humans can tolerate because of enzyme specificity or the relative harmfulness of the products?
• What do intelligent mammals like primates do with their dead?
• Are there any genes whose expression is -not- regulated?
• Why does Mercury's solar transit ONLY happen every ~ 10 or so years?
• [Physics] Could a human swim in a column of water only supported by atmospheric pressure?
• How dense of a gravity field to bend a LASER around a circle 180 degrees?
• What did primitive humans used to sleep on?
• Why can I block most of the light when I hold my hand between me and a light source, but I can't block most of the sound when I hold my hand between me and a sound source?
• How loud (in DB) is a bullet in flight? Excluding the initial blast.
• Through the removal of the zona pellucida, could sperm from any animal fertilize an egg? And if so, how realistic are chimeras?
• Why don't physicists like to talk about the vacuum catastrophe?
• How far can you actually see when looking at the sky?
• Why would an increase in mean free path mean an increase in thermal conductivity?
• Why is a dust particle floating upward in my room?
• If protons & neutrons are each composed of 3 quarks, is the atomic nucleus just a jumble of quarks, or is each set of 3 quarks a distinct particle?
• Did the early universe have an escape velocity higher than the speed of light?
• Ask Anything Wednesday - Physics, Astronomy, Earth and Planetary Science
• Would you see better resolution in optic microscopes if you used purple LEDs for lighting?

Did relativity HAVE to be discovered mathematically? Could we have discovered the exact equations empirically? Say from observing the difference in clocks on the ground vs on satellites Posted: 04 May 2016 04:25 PM PDT submitted by /u/tangentZero [link] [comments]

What would happen if you were struck by a tic tac traveling ~1% the speed of light? Posted: 04 May 2016 05:39 PM PDT submitted by /u/ByzantineFire [link] [comments]

Why aren't there pure ATP supplements available on the market as energy boosters? What would happen if you took these? Posted: 04 May 2016 12:11 PM PDT As ATP is often referred to as the energy currency of the cell, what would happen if one ingested ATP capsules? Would the person experience an energy boost, or would it prove to be toxic? submitted by /u/kash1f [link] [comments]

Many people argue that First-Past-the-Post voting system is the worst. Arrow's theorem says that there is no perfect voting system. Is there a way to mathematically quantify the utility of a voting system, and if there is, then which one comes out on top? Posted: 04 May 2016 08:30 PM PDT submitted by /u/haqshenas [link] [comments]

After watching a video flyover of Titan, I wondered how scientists delineate one pole as "north" and the other as "south" on non-earth bodies? Magnetism? Alignment with the solar plane? Other? Posted: 04 May 2016 09:56 PM PDT submitted by /u/AusCan531 [link] [comments]

If sucrose has a lower enthalpy of combustion than octane, why can't we / don't we use it as a fuel? Posted: 04 May 2016 09:03 PM PDT I understand there might be some technical difficulties with running engines on sugar, but if our bodies can utilize the energy why can't mimic their processes to run engines on sugar? submitted by /u/Vivalas [link] [comments]

Is ethanol the only alcohol that humans can tolerate because of enzyme specificity or the relative harmfulness of the products? Posted: 04 May 2016 12:12 PM PDT Humans can only tolerate ethanol. Ethanol and NAD+ are converted to acetaldehyde and NADH by alcohol dehydrogenase. Acetaldehyde and NAD+ are then converted to ethanoic acid and NADH by aldehyde dehydrogenase. So is it that one (or both) of these enzymes is specific to two-carbon molecules, or is it that the by-products from a reaction with methanol, isopropyl alcohol, etc. are more potent in their toxicity? EDIT: I am guessing the former, because enzymes essentially lower the energy of the transition state by making hydrogen bonds and forcing molecules into a specific conformation. This means there isn't room for extra carbons because hydrogen bonds can only occur within a window of ~1 Angstrom (it's like 2-3 Angstroms away for an H-bond, I think). Wikipedia is not specific enough and the articles I'm reading don't address the physiology. Correct me on any of this. submitted by /u/DrunkNotThatFlexible [link] [comments]

What do intelligent mammals like primates do with their dead? Posted: 04 May 2016 05:46 PM PDT submitted by /u/wootini_ [link] [comments]

Are there any genes whose expression is -not- regulated? Posted: 04 May 2016 10:09 PM PDT submitted by /u/thealephgimel [link] [comments]

Why does Mercury's solar transit ONLY happen every ~ 10 or so years? Posted: 04 May 2016 07:07 PM PDT I've always wondered why these are so rare: http://www.space.com/32784-mercury-transit-2016-sun-viewing-guide.html Is the irregularity of Earth and Mercury's inclination the reason why we don't see these more often? Mercury's orbital period is 88 Earth days, shouldn't alignments happen more often? Thanks for the explanation. submitted by /u/Jonnyslide [link] [comments]

[Physics] Could a human swim in a column of water only supported by atmospheric pressure? Posted: 04 May 2016 07:25 AM PDT Here are the conditions: Pipe: Length: 10 m. Diameter: 3 m. Oriented vertically. Top end closed off. Bottom end open. Pressure at the top of the column inside the pipe is zero. Pressure at the bottom of the column is equal to the atmospheric pressure. As far as I understand, the atmospheric pressure would be able to support a 10 m column of water according to basic hydrostatics. Now, could you enter this pipe from below and swim inside? It seems plausible on paper, but really fucks with my imagination. Tried to search google and reddit for the answer, but it is not an easy question to phrase for a norwegian. submitted by /u/sjarls [link] [comments]

How dense of a gravity field to bend a LASER around a circle 180 degrees? Posted: 04 May 2016 05:51 PM PDT I was thinking about bending light around a corner as an alternative to using a mirror. I was wondering how dense of a gravity field to bend light or space 180 degrees, as if the light beam orbitted a briefly-existing blackhole for half an orbit then flying straight out like a tangent. Parallel to initial entry direction. Note: that the diameter of the black hole should be the size of a golf ball. submitted by /u/GreenAce92 [link] [comments]

What did primitive humans used to sleep on? Posted: 04 May 2016 06:32 PM PDT submitted by /u/gorightthroughformsu [link] [comments]

Why can I block most of the light when I hold my hand between me and a light source, but I can't block most of the sound when I hold my hand between me and a sound source? Posted: 04 May 2016 03:09 PM PDT submitted by /u/The_Godlike_Zeus [link] [comments]

How loud (in DB) is a bullet in flight? Excluding the initial blast. Posted: 04 May 2016 04:32 PM PDT Let's use the 5.56x45mm and 7.62x39mm as examples. The 5.56 has a faster velocity at 940m/s than the 7.62 at 730m/s and being lighter in weight as well. Assuming that they are fired from a M16 and an AKM, for all intent and purposes. Would the difference in mass and velocity create a difference in the amount of sound they create? How far would the sound travel while in flight? submitted by /u/nguyenm [link] [comments]

Through the removal of the zona pellucida, could sperm from any animal fertilize an egg? And if so, how realistic are chimeras? Posted: 04 May 2016 07:37 PM PDT I know that some hamster chimeras have been created, but I'm more interested in animals "a bit" further from each other; for example crossing dolphins and whales. Would there be any viable combinations outside "naturally" occurring ones like Ligers (including combinations that lead to abnormalities, the animal just needs to not die)? Additionally, what possible genetic abnormalities would be seen? submitted by /u/onellabonella [link] [comments]

Why don't physicists like to talk about the vacuum catastrophe? Posted: 04 May 2016 08:03 PM PDT I have been into physics for a long time but I never heard about this. I actually had to look for it ( before I knew it was a thing) to find mention of it. submitted by /u/Instantattrition [link] [comments]

How far can you actually see when looking at the sky? Posted: 04 May 2016 04:16 PM PDT I have been directed from r/AskReddit to post this question here. submitted by /u/MattMcflow72 [link] [comments]

Why would an increase in mean free path mean an increase in thermal conductivity? Posted: 04 May 2016 03:40 PM PDT If I'm understanding this correctly, mean free path is the distance an energy carrying molecule must go before a collision, which is when the energy is transferred. If the path is longer, wouldn't that mean energy is transferred less often or efficiently, making it a better insulator? submitted by /u/MaverickTopGun [link] [comments]

Why is a dust particle floating upward in my room? Posted: 04 May 2016 04:17 PM PDT I'm in an indoor room. The windows are closed. Doors are shut. No air is coming through the vents. But I see a dust/lint/feather/whatever particle floating upward toward the ceiling. How is it floating upwards? Why does it float upwards instead of gravity making it fall to the ground? submitted by /u/orangero [link] [comments]

If protons & neutrons are each composed of 3 quarks, is the atomic nucleus just a jumble of quarks, or is each set of 3 quarks a distinct particle? Posted: 04 May 2016 10:54 PM PDT https://en.wikipedia.org/wiki/File%3AQuark_structure_neutron.svg This graphic shows a neutron as a set of 3 quarks bound together with a 'shell' around them. This shell is presumably not an actual massive object (what would it be composed of after all?). But in an atomic nucleus, several (up to 100s) of these quark sets are combined together. Does each nucleon (proton and neutron) remain a distinct particle or is the nucleus simply a jumble of up and down quarks? If the former, what prevents quark sets (nucleons) from dissembling, moving around and mixing like atoms in a gas or liquid? If the latter, why even bother talking about protons and neutrons as an intermediate step? submitted by /u/spacepilot4000 [link] [comments]

Did the early universe have an escape velocity higher than the speed of light? Posted: 04 May 2016 02:10 PM PDT With my limited understanding of physics I would think that in the moments after the big bang, the escape velocity of the incredibly dense universe would exceed the speed of light. Applying my (again very very limited) understanding of physics that would mean that all the matter fell back into a singularity, while space itself would keep expanding practically empty. Why is this not the case? Was the space between quarks/early matter simply expanding fast enough that all the objects were effectively moving away at FTL speeds? submitted by /u/ElkossCombine [link] [comments]

Ask Anything Wednesday - Physics, Astronomy, Earth and Planetary Science Posted: 04 May 2016 08:05 AM PDT Welcome to our weekly feature, Ask Anything Wednesday - this week we are focusing on Physics, Astronomy, Earth and Planetary Science Do you have a question within these topics you weren't sure was worth submitting? Is something a bit too speculative for a typical /r/AskScience post? No question is too big or small for AAW. In this thread you can ask any science-related question! Things like: "What would happen if...", "How will the future...", "If all the rules for 'X' were different...", "Why does my...". Asking Questions: Please post your question as a top-level response to this, and our team of panellists will be here to answer and discuss your questions. The other topic areas will appear in future Ask Anything Wednesdays, so if you have other questions not covered by this weeks theme please either hold on to it until those topics come around, or go and post over in our sister subreddit /r/AskScienceDiscussion , where every day is Ask Anything Wednesday! Off-theme questions in this post will be removed to try and keep the thread a manageable size for both our readers and panellists. Answering Questions: Please only answer a posted question if you are an expert in the field. The full guidelines for posting responses in AskScience can be found here. In short, this is a moderated subreddit, and responses which do not meet our quality guidelines will be removed. Remember, peer reviewed sources are always appreciated, and anecdotes are absolutely not appropriate. In general if your answer begins with 'I think', or 'I've heard', then it's not suitable for /r/AskScience. If you would like to become a member of the AskScience panel, please refer to the information provided here. Past AskAnythingWednesday posts can be found here. Ask away! submitted by /u/AutoModerator [link] [comments]

Would you see better resolution in optic microscopes if you used purple LEDs for lighting? Posted: 04 May 2016 07:44 AM PDT The idea is that the maximum zoom, (resolution) of an optic microscope is limited by the wavelength of the light, so under usual lighting the realistic maximum zoom, keeping the image crisp, is about 2000x. That is with with ideal oil submersion. My question is, since purple light has the shortest visible wavelengths, if you had purple LED lighting instead of white, would you be able to get better resolution images? If so, by how much? submitted by /u/Zombekas [link] [comments]

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