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Sunday, June 18, 2017

The existence of heavy elements on Earth implies our Solar System is from a star able to fuse them. What happened to all that mass when it went Supernova, given our Sun can only fuse light elements?

The existence of heavy elements on Earth implies our Solar System is from a star able to fuse them. What happened to all that mass when it went Supernova, given our Sun can only fuse light elements?


The existence of heavy elements on Earth implies our Solar System is from a star able to fuse them. What happened to all that mass when it went Supernova, given our Sun can only fuse light elements?

Posted: 18 Jun 2017 05:09 AM PDT

How do developers of programs like firefox process crash reports?

Posted: 18 Jun 2017 05:08 AM PDT

They probably get thousands of automatically generated crash reports every day

do they process each of them manually, is there a technique to evaluate them automatically or do they just dump most of them?

submitted by /u/KippieDaoud
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Why do rapidly flashing lights / rapidly changing images cause epileptic seizures?

Posted: 17 Jun 2017 10:24 PM PDT

Nothing really to add here, just the question in the post.

submitted by /u/No_name_Johnson
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When I "see heat waves" rising from a hot, dry street, what is it that I'm actually seeing?

Posted: 17 Jun 2017 11:50 PM PDT

Besides the Turing Test, is there any other checkbox that must get ticked before we can say we invented true artificial intelligence?

Posted: 18 Jun 2017 02:54 AM PDT

Why does a reactor meltdown, such as with Chernobyl, create a much longer lasting exclusion zone than a nuclear warhead detonation site?

Posted: 17 Jun 2017 06:52 PM PDT

When things like bridges enter a harmonic frequency where does all the energy come from?

Posted: 17 Jun 2017 09:11 PM PDT

An example video: https://www.youtube.com/watch?v=j-zczJXSxnw

Where is all this energy stored? It seems like such a massive amount to move a bridge I don't understand how it's possible. Does it come from the earth? The wind?

submitted by /u/mrtwoohsix
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Are there any robust ways to measure large distances (100 meters) between objects to a subatomic level of accuracy?

Posted: 18 Jun 2017 05:17 AM PDT

How dark is outer space?

Posted: 17 Jun 2017 07:53 PM PDT

If you got far enough into space, away from the sun or another star, would you still be able to see your hand in front of your face, or would it be too dark?

submitted by /u/cbassmn
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How many times can a piece of plastic be recycled?

Posted: 17 Jun 2017 07:08 PM PDT

What happens to compounds when a radioactive isotope decays?

Posted: 18 Jun 2017 06:21 AM PDT

As the title says, how does decay affect compounds. For example, take carbon-14. If say the carbon in a carbon dioxide molecule decays, the carbon would release a beta particle and turn into nitrogen. How does this affect the compound that was carbon dioxide. Does it just break apart?

submitted by /u/eliteal
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When burning liquid oxygen, what temperature is the flame?

Posted: 18 Jun 2017 05:32 AM PDT

When liquid oxygen is burning, what temperature is the flame? And while your here, what is a subzero flame, how can I make one, what cool stuff do they do?

submitted by /u/Mandrake7287425
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What would have happened if the solar storm of 2012 directly hit the Earth?

Posted: 18 Jun 2017 05:17 AM PDT

What are the ramifications of a severed transatlantic cable for an average person?

Posted: 17 Jun 2017 09:07 PM PDT

I'm trying to understand how important transatlantic cables are to average people. Would my internet go out, my phone stop receiving data/calls, etc?

submitted by /u/aga_blag_blag
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Why are many computer parts built around multiples of 8?

Posted: 17 Jun 2017 08:57 PM PDT

Why is a beam of high speed electrons required to produce x-rays?

Posted: 18 Jun 2017 07:03 AM PDT

The electrons are accelerated at a tungsten target, when they hit, the kinetic energy converts to heat energy, emitting x-rays due to thermal radiation. Why are all these steps necessary, could they not just make x-rays by heating a tungsten coil to the required temperature with regular current?

Edit: Thermal radiation, not thermionic emission.

submitted by /u/justpureironical
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If an object is infinitely falling in a vacuum will it be constantly accelerating? Would it be able to reach the speed of light?

Posted: 18 Jun 2017 06:52 AM PDT

Assume there's a portal on the ceiling and a portal on the floor and an object is falling between the two

submitted by /u/CaptainGorgonzola
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Why does aloe help with sunburn?

Posted: 17 Jun 2017 06:24 PM PDT

Why are some new roads built out of concrete, while others are made of asphalt?

Posted: 17 Jun 2017 05:41 PM PDT

Does centrifugal force exist or are people using a made up [but commonly accepted] term to describe inertia?

Posted: 17 Jun 2017 10:16 PM PDT

When I took physics in high school, our teacher drilled into our heads that "centrifugal" force is commonly used to describe the opposite to centripital force; however, the term for this is actually inertia, and saying "centrifugal" is incorrect.

submitted by /u/unleash_the_booty
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How do we shield against Gamma Rays?

Posted: 18 Jun 2017 01:13 AM PDT

According to this website:

"γ GAMMA: To reduce typical gamma rays by a factor of a billion, thicknesses of stop-gammashield need to be about 13.8 feet of water, about 6.6 feet of concrete, or about 1.3 feet of lead. Thick, dense shielding is necessary to protect against gamma rays. The higher the energy of the gamma ray, the thicker the shield must be. X-rays pose a similar challenge. This is why x-ray technicians often give patients receiving medical or dental X-rays a lead apron to cover other parts of their body."

Source:

http://www.nuclearconnect.org/know-nuclear/science/protecting

You would need 1.3 feet of lead to shield against Gamma rays.

My question is, are there more practical ways of shielding against Gamma rays?

I've read that deep space travel is largely impractical as of now, because we have no means of shielding the prolonged exposure to gamma rays.

Besides lead, what are more practical methods of protection from gamma rays?

submitted by /u/hockeyboi
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Is there any evidence that honey bees have another metamorphosis phase that we're unaware of?

Posted: 18 Jun 2017 04:58 AM PDT

Is "intergalactic space" a different temperature from normal space?

Posted: 17 Jun 2017 05:16 PM PDT

I was attempting to learn about space via Wikipedia and it began talking about "rarefied plasma" and the "intergalactic medium" which heats up. Sorry if this question is asked in a really awkward way.

submitted by /u/ViktorMacbeth
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Saturday, June 17, 2017

How do solar panels work?

How do solar panels work?


How do solar panels work?

Posted: 17 Jun 2017 06:09 AM PDT

I am thinking about energy generating, and not water heating solar panels.

submitted by /u/KeesoHel
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What caused the Chernobyl reactor to explode?

Posted: 17 Jun 2017 05:53 AM PDT

I am researching the Chernobyl accident and what made the reactor explode. I found this page which explains it pretty well http://230nsc1.phy-astr.gsu.edu/hbase/NucEne/cherno.html#c5 but there are still som technicalities i don't think i quite understand. If any of you are familiar with the accident and reactor physics i would love some help! Questions: How did they make the reactor run at "Low power"? Why was the cooling system turned off/low power and why did they have to turn the emergency cooling system off? I hope i am not violating any subreddit rules, ty for your time :)

submitted by /u/Valcuri
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Can astronauts with astigmatism wear contact lenses in space?

Posted: 16 Jun 2017 02:22 PM PDT

The lenses in the eyes of people with astigmatism focus differently in different directions. Corrective lenses for astigmatism, therefore, also have to focus differently in different directions. Contact lenses that correct for astigmatism are weighted so that their orientation correction is gravity assisted. Is there a different technology that could work in free fall?

I'm not sure if I should flair this question as physics, biology, medicine, or engineering.

submitted by /u/pez78guy
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Why is molten iron orange?

Posted: 16 Jun 2017 05:59 PM PDT

Recently there was a discussion between me and my friends and we had a little disagreement about the colour of molten iron. (All beginning with this video here: https://www.youtube.com/watch?v=8E6TzT0eCYs)

To my understanding: Every object "glows" the same colour at the same temperature. Beginning from red through orange to white depending on how hot they are.

Now Iron has a melting point of 1.538 °C. According to wikipedia things should begin to glow white at around 1500°C. Now like the video said molten iron has to be a little bit hotter than the melting point or else it would solidify "instantly" when you try to pour it.

So even if the white glowing doesn't happen straight at 1500°C, molten iron, in order to pour it, should be a lot hotter and be white.

So here is my question: Why is the colour of molten iron in movies or book descriptions or even when you google "molten iron pictures" always bright orange? Shouldn't it be at least yellow?

Thanks a lot guys! :)

submitted by /u/da_neo
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If you were to shine a light at a black hole directly, would the speed of the photons increase past the speed of light because of the powerful pull adding to the current speed?

Posted: 16 Jun 2017 06:33 PM PDT

Are there trace elements heavier than hydrogen inside a star?

Posted: 16 Jun 2017 05:38 PM PDT

To specify are there heavier elements being created in our sun right now? Can a magnesium atom be created by an area of high temperature/pressure and find its way to the surface?

submitted by /u/striker7770
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Questions on spacecrafts - is it possible to actually take off and land back onto a planet in one?

Posted: 16 Jun 2017 05:42 PM PDT

IRL it takes a massive rocket with a huge amount of fuel just to get a handful of people and some supplies off the ground and into space. However in every Sci-Fi movie or book ever made there are always small, sometimes even large space craft that are capable of flying right off the ground and into space, as well as flying through an atmosphere and back onto the ground without any complications. Is any of that actually possible?

Also, if we ever do send people to a planet similar to earth, what would happen once they come into contact with the environment? In a lot of movies, the human crew just casually walks off the space ship and onto a planet, sometimes without any kind of protective suit (Like in Alien: Covenant). Wouldn't that be a bad idea?

submitted by /u/Krahz
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Why was there no Nobel-prize for GR?

Posted: 16 Jun 2017 11:04 AM PDT

From Wikipedia: General relativity is considered as the most beautiful of all existing physical theories.

GR was the first theory to add things to Newton's law in 300 years. Why wasn't it awarded the Nobel prize?

submitted by /u/Lionh34rt
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What do ants do about flooding from rain or other disasters?

Posted: 16 Jun 2017 04:27 PM PDT

Mostly concerned with flooding from spilled water or rain but I imagine there are other disasters that can affect a hill or colony.

submitted by /u/Boom2215
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Why does every launch related to the ISS take place in Kazakhstan?

Posted: 16 Jun 2017 03:51 PM PDT

Why is cumulative aircraft stress measured in hours rather than mileage?

Posted: 16 Jun 2017 02:17 PM PDT

Wouldn't total distance travel account for a more sensitive measurement of stresses from air resistance and vibration provided to the aircraft its life? My (probably wrong) assumption is that hours does not reflect changes in speed over a single trip and multiple trips. An 777 cruising at Mach 0.82 probably accumulates more stress than if it was traveling at Mach 0.7 - because air resistance is related to the square of velocity?

submitted by /u/z3roTO60
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How do we know some prehistoric animals laid eggs?

Posted: 16 Jun 2017 10:11 AM PDT

Can we Ride a Comet?

Posted: 16 Jun 2017 06:05 PM PDT

is it possible to attach ourselves and use the comet

submitted by /u/X4217
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Would non-uniform Expansion explain the CMB variance?

Posted: 16 Jun 2017 08:46 AM PDT

As happens in physics, the thought occurred to me today seemingly out of the blue. I never finished my BS in Physics, though, so I'm wondering if there is a difference between the model of non-uniform expansion and quantum-fluctuation-driven variance in the CMB? It seems to me that if space stretched slightly faster in one area than another, you'd get cold and warm spots just like the current model of fluctuations.

EDIT: RE: Title, I meant to type "Inflation," but didn't. Whoops, my bad. Also, Acronyms for those unfamiliar, I'm talking about the Cosmic Microwave Background [Radiation], which is everywhere, and extremely, but not quite, identical.

submitted by /u/VirtualMachine0
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If a constant flame is applied, does a hot air balloon's vertical climb rate increase as it gets higher?

Posted: 16 Jun 2017 11:18 AM PDT

I was discussing balloons at some point with my co-workers and I had this random thought and became very curious. My thought is as the air becomes less dense, it would be applying less downward force on the balloon, allowing the balloon's climb rate to increase.

submitted by /u/absolut07
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How fragile is the space shuttle engine (bell)?

Posted: 16 Jun 2017 02:24 PM PDT

I was perplexed when i got told that each of the little tubes in a space shuttle rocket bell (maybe not only the space shuttle ones) are each tiny fuel lines for cooling. I wondered what would happen if one of those tubes... broke/exploded/melted, would the whole engine fail?

submitted by /u/RottenIceTea
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Aside from looking at fossils, are there other geological ways to determine the different climate changes the Earth has gone through in the past?

Posted: 16 Jun 2017 10:00 AM PDT

I've been looking around online to see if there were any ways to understand the past climates of an area by studying the geology in that area. I found a few results, but almost all of them seem to suggest that looking at fossils and observing their characteristics is the only way. Which made me curious, are there other ways of looking at sediment, rock formations etc. to try to determine the climate timeline of an area that don't include looking at fossils?

submitted by /u/TheMaroonAxeman
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Why is download speed often much faster compared to upload speed?

Posted: 16 Jun 2017 01:28 PM PDT

Are isotopes of elements evenly distributed throughout the natural world?1

Posted: 16 Jun 2017 12:31 PM PDT

For instance, will random samples of oxygen, or another element yield approximately the same ratio of isotopes? Or are groups of given isotopes grouped together for some reason?

submitted by /u/willwcb
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Why did it take so long to discover the first pulsar?

Posted: 16 Jun 2017 09:49 AM PDT

I recently read that the first pulsar wasn't discovered until 1967 by astronomers. Since we have been staring at the sky for millennia, and as far as I understand, we can see a pulsar's blinking light with the naked eye (with a telescope), are there any good explanations out there for why we took so long to find one?

submitted by /u/raindog42
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Friday, June 16, 2017

Does multi-verse theory allow for variation in the laws of physics or must the laws of physics be constant across all universes?

Does multi-verse theory allow for variation in the laws of physics or must the laws of physics be constant across all universes?


Does multi-verse theory allow for variation in the laws of physics or must the laws of physics be constant across all universes?

Posted: 15 Jun 2017 09:12 PM PDT

What Mechanism Produces Black Body Radiation?

Posted: 16 Jun 2017 02:54 AM PDT

I have spent about a half hour trying to google this, and I always get the same page often titled "How is black body radiation produced?" that keeps on telling me what black body radiation does after it's radiated.

I learned long ago about the basic equations used to describe the phenomenon or how to calculate the spectral lines, and I'm very familiar with how a spectrum with a graph on it looks. None of these answer my question.

So Reddit please save me. HOW is black body radiation actually produced on the quantum level? What mechanism takes place to generate the actual photon and what parts of the atom are involved, what are the specific quantum interactions, and which specific Fermions and Bosons are doing what in what way? What energies are involved?

I realize this will have at least 3 different answers depending on the phase of the material, and that there is quite a bit of cross over with thermal radiation.

Bonus: How do monatomic gases emit black body radiation in rare cases?

submitted by /u/Radiatin
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How often do animals known for their quickness or agility (like a deer or cheetah) tear ligaments or pull muscles?

Posted: 16 Jun 2017 06:15 AM PDT

Would botulism leave any diagnostic trace a year after someone suffers from it?

Posted: 15 Jun 2017 08:52 PM PDT

North Korea claims the American student, Otto Warmbier, had a case of botulism before being sedated and falling into a coma. He is now in a vegetative state. The American doctors examining him stated that they found no evidence of botulism,

"As part of his evaluation with us, we performed electromyography and nerve conduction studies. Those tests did not reveal any evidence…that would suggest active botulism at this time."

But it is unclear what exactly they meant by that statement. Botulin, the toxin, would presumably have left the body after 4 or 5 months, no? So of course there would be no "active botulism".

So my question is, am I interpreting their statement correctly? It either means everything (he didn't have botulism), or it means nothing (because one wouldn't even expect to observe active botulism after more than a year). Which one is it?

submitted by /u/tinkletwit
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Why do coral reefs not grow in the Gulf of Mexico but thrive in areas like that of the Caribbean islands?

Posted: 16 Jun 2017 07:15 AM PDT

Is there an official time/clock by which all other clocks are set?

Posted: 16 Jun 2017 06:24 AM PDT

Is there something close to an international standard? Do different countries do their own thing (if even that)?

And if this/these thing(s) exist, how do we know they're accurate?

submitted by /u/stilnomen
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Will a lost ant seek out a new colony and will a colony accept outsiders?

Posted: 15 Jun 2017 06:48 PM PDT

Lets say an ant crawls onto my car and I drive 50 miles away. Will that ant actively seek out a new colony? And if it did, will a colony assimilate it? Or are lost ants SOL?

submitted by /u/Jerf1
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Why does wind "die down" at night?

Posted: 15 Jun 2017 07:11 PM PDT

Why doesn't deuterium fusion occur in main sequence stars?

Posted: 16 Jun 2017 07:37 AM PDT

What makes the proton-proton chain reaction the preferred method of fusion in main sequence stars if deuterium fusion occurs at lower temperatures? Following that, why does the carbon-nitrogen-oxygen cycle become the preferred method of fusion in stars starting around 1.3 solar masses?

submitted by /u/spiff87
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If a fidget spinner was brought into the void of space, could it potentially spin forever?

Posted: 16 Jun 2017 06:46 AM PDT

(Negating the friction caused by the bearings)

submitted by /u/FelixST64
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Why is it so common for people to have reoccurring dreams where their teeth fall out?

Posted: 15 Jun 2017 05:19 PM PDT

What is the volume of soil erosion caused by humans and does it have any affect on sea level rise?

Posted: 16 Jun 2017 04:09 AM PDT

Why do doctors still use stitches that need to be removed instead of dissolving ones?

Posted: 15 Jun 2017 05:26 PM PDT

Do you get more sun burnt when it's hotter out?

Posted: 15 Jun 2017 12:18 PM PDT

Why does water always taste 'flat' when you leave it out overnight?

Posted: 15 Jun 2017 10:02 AM PDT

How do wind speeds change with altitude. The general rule of thumb is the higher you are, the faster wind is. At what altitude does this change?

Posted: 16 Jun 2017 02:01 AM PDT

What is the wind speed at 30'000 meters, for example? If this varies with location/weather, my question would concern Europe/Switzerland. Thank you for any answers, I've been asking people for days now and googling but haven't had any luck.

submitted by /u/Captionater
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If we had not reduced our production of Ozone depleting gases but had stayed on a "business as usual" scenario, how bad would the UV radiation problem be by now?

Posted: 15 Jun 2017 05:56 AM PDT

Where is salt actually formed? Rivers or oceans?

Posted: 15 Jun 2017 05:00 PM PDT

This is what I understand: the water cycle moves sodium ions from land into the ocean. Volcanic eruptions add chlorine ions to the ocean water. When these sodium and chlorine ions were in the ocean x years ago, they bonded to make salt.

So does salt come from oceans or land/rivers?

submitted by /u/plantfollower
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When wire is coiled to create an electromagnet why does the electric current follow the wire instead of taking the shortest path through the sides of each turn?

Posted: 15 Jun 2017 11:33 AM PDT

It often appears that coils do not have insulating layers between the turns. What prevents the electricity from simply skipping between turns in the coil and undermining the intended effect? How is a coil of uninsulated wire different from a cylinder of solid metal?

submitted by /u/omgtater
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