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Saturday, June 1, 2019

What is the force that drives light to move at the speed that it does? Or to put more simply, what propels light?

What is the force that drives light to move at the speed that it does? Or to put more simply, what propels light?

What is the force that drives light to move at the speed that it does? Or to put more simply, what propels light?

Posted: 01 Jun 2019 07:46 AM PDT

I understand that light travels really fast. I know that is an understatement but anyway, what is it that propels light forward to move at the speed that it does without ever slowing down?

submitted by /u/Adrous
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Do gasses have a similar concept to “laminar flow”?

Posted: 01 Jun 2019 08:22 AM PDT

I am asking if the actual definition of laminar flow for liquids has a parallel in gasses.

I'm just a 16 year old so I need a second guess on this but my theory was that gasses just don't (without extreme intervention) because gasses aren't usually uniform in composition and the difference in density causes chaos. I wouldn't even begin to guess about what could happen if you could test with all of one gas and no others.

submitted by /u/Spart_
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What’s the liquid that starts bubbling on the wood when you strike a match?

Posted: 01 Jun 2019 07:08 AM PDT

At the end of its life, can a red giant star’s mass be expelled to leave an iron core as opposed to a neutron degenerate core?

Posted: 01 Jun 2019 07:37 AM PDT

Can the processes of age occur in a star while not letting it collapse to neutron degeneracy?

I've never heard of an iron core, so then why do they always reach their critical mass to collapse into a neutron degenerate core? I suppose this applies to white dwarfs as well.

submitted by /u/pizzafoot_1057
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Does light of different wavelengths have different speeds in a medium?

Posted: 01 Jun 2019 05:30 AM PDT

So I was looking at the standard textbook illustration of glass prism spreading a light ray into rainbow when it hit me: if colors get separated, they must change by a different angle when entering the prism - and since tge angle is a function of speeds in air and glass, that would mean different colors travel at different speeds in glass.

Is that the case? Which colour travels the fastest and which the slowest? Does the effect persist for wavelengths beyond visible light? Why don't we see same effect for light enterring out atmosphere (or do we and it's just not significant enough)?

And most importantly, why was this never mentioned in school?

submitted by /u/Naturage
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Why is the Florida Coast Darkened?

Posted: 01 Jun 2019 06:39 AM PDT

Hi, native Floridian here and new to this page.

I was on Google Maps earlier and noticed that the gulf coast between Eastpoint and Homosasa is all blacked-out or much darker than the rest of the coastline. Is this from environmental disaster, deep water, or something else? It just seems so odd that just this one section is wildly darker than the rest.

submitted by /u/sakilp863
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How does our body know when to wake up in the morning?

Posted: 01 Jun 2019 04:37 AM PDT

Has cancer always been as big a threat historically as it is now?

Posted: 01 Jun 2019 04:03 AM PDT

I hear a lot about people dealing with cancer in the news or in personal conversation all the time, but I realized that despite how devastating it can be, I cannot recall hearing about a single instance of anyone dying from cancer before the 20th century.

As someone who has lost relatives to the disease, I have unfortunately seen firsthand how devastating it can be, which in turn has led me to question why there are so few historical mentions of it.

This makes me wonder if the prevalence of cancer throughout our society is only a modern occurrence, or if it has been a threat throughout history that I have just been unaware of.

Is this the case here, or has there been something that has led to an increase in cancer cases in the 20th century and beyond?

submitted by /u/ohLawdyWhatDidIDo
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Are there names for the different areas of charge in thunder clouds?

Posted: 01 Jun 2019 04:36 AM PDT

From research (googling - sort of research), I've learnt that when thunderclouds form the smaller, positively-charged ice crystals (hydrometeors) move towards the top of the cloud and the the heavier, negatively charged ice crystals (also just hydrometeors) move towards the bottom. Lightning occurs between these two regions, of the lower region and the ground.

I cannot find names for these two regions. Are there specific names? If so, what are they?

submitted by /u/RegularHovercraft
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Do black holes technically have no dimensions or more than we can process?

Posted: 01 Jun 2019 05:29 AM PDT

Physically imagining black holes, I view them as having width and length, and possibly depth. I don't know if this is necessarily true. I'm not an expert on this sort of stuff. I have also heard, I don't know if this is necessarily accurate, that black holes are one point of extreme gravity, and because points are Zero-dimensional, therefore a black hole wouldn't have dimensions? Either way I'm not sure.

submitted by /u/LOL543213
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Why are there extreme differences of temperature accros the world?

Posted: 01 Jun 2019 04:57 AM PDT

So the earth is tiny compared the sun and million miles away so why do we have such extreme temperature differences on earth when all the countries are basically the same distance from the sun?

submitted by /u/2HeckinLlamas
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Will it be possible to observe the 2024 moonlanding from earth?

Posted: 01 Jun 2019 04:18 AM PDT

I was just wondering if it will be possible to watch or record the upcoming moonlanding from earth using telescopes.

submitted by /u/KikiBreiter
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How does medicine cure depression?

Posted: 31 May 2019 12:11 PM PDT
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Friday, May 31, 2019

Did the plague doctor masks actually work?

Did the plague doctor masks actually work?

Did the plague doctor masks actually work?

Posted: 31 May 2019 07:38 PM PDT

For those that don't know what I'm talking about, doctors used to wear these masks that had like a bird beak at the front with an air intake slit at the end, the idea being that germs couldn't make their way up the flute.

I'm just wondering whether they were actually somewhat effective or was it just a misconception at the time?

submitted by /u/Edenspawn
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Why do people say that when light passes through another object, like glass or water, it slows down and continues at a different angle, but scientists say light always moves at a constant speed no matter what?

Posted: 31 May 2019 01:33 AM PDT

How common were dinosaurs?

Posted: 30 May 2019 09:56 PM PDT

It sounds dumb but hear me out. In movies, we always see dinosaurs in a mass quantity, squished together and nearly on top of each other. But if we were to go back right now, how often would you see dinosaurs? What would be the density of dinosaur life? What modern day animal sightings could you compare dinosaurs with? I really hope this question makes sense, but I can elaborate more if I have to. Thanks!

submitted by /u/BigMacs-BigSack
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What's the difference between a free photon and photon as a force carrier?

Posted: 31 May 2019 08:27 AM PDT

I want to understand how photons work. Apparently the light that flies through the void of space is made from photons. But the electromagnetic fields that surround us at all times, including our TV and WiFi and what have you, are also made of photons that carry interactions between charged particles. And somehow, in both cases photons are bosons, have no mass and no charge. I understand that by "light" we usually understand just its IR, visible and UV spectra, and that light and radio and gamma rays are actually all EM, just of different frequencies, but still, how does all that work? If light is made of photons, why doesn't light have charge? If electromagnetism is carried by photons, why don't they have charge? What's the difference between a photon of light that flew into my eye after being emitted by the Sun, and photon that carries my WiFi signal?

submitted by /u/MajesticS7777
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How much backup diesel fuel are nuclear power plants in the United States required to have? Days, weeks?

Posted: 31 May 2019 08:43 AM PDT

So nuclear power plants have backup diesel generators when the plant has to shut down for any reason. I can't seem to find information on how long this fuel supply is supposed to last though. Surely there's a minimum amount set by law or something.

submitted by /u/Sourpowerpete
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When it comes to brain damage from trauma, especially issues regarding perception (hemispatial neglect, for example), can a subject in any case "force" themselves to accept that their senses are deceiving them?

Posted: 31 May 2019 08:53 AM PDT

For example, if I were to one day have a stroke that led me to suspect that my wife had been replaced by an impostor, would I be doomed to believe it, or would I be capable of rationalizing that something had gone wrong inside my head, even though it might feel like she's been replaced?

submitted by /u/StChas77
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How does 5-HT1A Autoreceptors work and affect the Amygdala?

Posted: 31 May 2019 08:34 AM PDT

Hi,

​

Is anybody familiar with 5-HT1A auto-receptor? I'm struggling to understand the function of it as an autoreceptor. I understand that it regulates 5-HT but I'm not sure what is the mechanism. Does it bind to the 5-HT that the neurons release and further release lesser 5-HT? I would then assume that more 5-HT1A autoreceptor = low levels of serotonin. Is that right? Thus, according to this paper: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2736132/ how does 5-HT1A affect amygdala reactivity? The paper suggests that more 5-HT1A autoreceptors = low amygdala reactivity = low anxiety. However, if 5-HT1A releases lesser serotonin, wouldn't lesser serotonin levels lead to high levels of anxiety?

Apologies if I'm confusing everybody, but this is my very naive current understanding of 5-HT1A autoreceptors. I really wish to understand this receptor and mechanism.

Thank you all.

submitted by /u/TheWildJerry
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Why are Uranium fuel pellets sintered?

Posted: 31 May 2019 08:32 AM PDT

I've been trying to educate myself on nuclear tech, and seeing that most fuel rods are pulled with around 90%+ good fuel due to contamination from waste products got me looking into the fuel.

I tried good ol' Google but I'm really struggling with this one.

Has anyone used fuel rods/pellets made from a grown single crystal rather than sintered? I'm trying to determine how that structure would retain/reject fission products vs the sintered pellet.

submitted by /u/crispysilicon
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If they did, how ~2000 tested nuclear weapons from 1945s impacted global warming?

Posted: 31 May 2019 05:42 AM PDT

Why does just about everything in space spin?

Posted: 30 May 2019 07:22 PM PDT

Galaxies, black holes, planets, solar systems, and stars rotate. Why?

And while I'm at it, why does stuff wind up orbiting stuff, instead of just flinging past each other or colliding already?

submitted by /u/rancid_oil
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What is a bose-einstein condensate?

Posted: 30 May 2019 09:47 PM PDT

I've long since wanted to know what a bose-einstein condensate is but even after looking it up several times (I've wanted to know for a long time) I still have no clue. I just can't wrap my mind around it. I can't visualize it and even after trying google images, I just find graphs and unrelated stuff. Like plasma, and PLEASE correct me if I'm wrong, I imagine as a sort of goop or runny slime consistency but generally in a ball. Also, I know it's a superfluid, does that also make it a fluid? Is a superfluid just a sub-category of fluid? Please help.

submitted by /u/Monkeyofdoom44
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How fast can Humans go (Moving through space) and survive? Assuming we don't accelerate so fast it kills us? And how long would it take to get to light speed?

Posted: 30 May 2019 10:28 PM PDT

Why do allergic reactions vary in severity? If the immune response kicks in, shouldn’t be an all or nothing response?

Posted: 31 May 2019 12:09 PM PDT

Why does water temperature affect its taste?

Posted: 31 May 2019 12:08 PM PDT

How does this work?

submitted by /u/Z2omek
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Is there such a thing as a "linked placebo" effect? For example, taking two drugs, then suddenly stopping one, but still receiving some of the effects of the other?

Posted: 31 May 2019 11:55 AM PDT

So say you take allergy pills, and they have caffeine in them. Is there any evidence that, if you were to stop taking the pills, but continue taking a similar amount of caffeine, you could get some of the other effects of the pills?

Even if that exact example doesn't work, are there others that do?

submitted by /u/Vandechoz
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Can a polarizer be turned on and off with electricity?

Posted: 31 May 2019 02:14 AM PDT

How does the composition of the atmosphere vary with altitude, if at all? [Earth Science]

Posted: 31 May 2019 09:24 AM PDT

What happens to major arteries which bring blood to extremities after an amputation?

Posted: 31 May 2019 08:57 AM PDT

The femoral artery is a large artery that supplies the legs. What happens to it after the leg is amputated?

What do surgeons do with this artery, tie it back into the return vein, or tie it off and let new vessels form?

What happens to the circulatory system after an amputation, does its overall efficiency increase because blood has to travel less distance, or does it get negatively impacted because the oxygen is not being fully used but instead traveling in the return vein without being used?

submitted by /u/LesboPregnancyScare
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What purpose does the actually Uvula serve?

Posted: 30 May 2019 10:13 PM PDT

Does a frog remember being a tadpole?

Posted: 30 May 2019 06:29 PM PDT

I recently watched a video simulating tadpoles growing into frogs, which got me wondering if the memory capacity of a frog is strong enough to really understand the freedom it now has with its legs or if it forgets it's time swimming about.

submitted by /u/Thundrstrm
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Relative to its overall lifespan, is the sun an old star?

Posted: 30 May 2019 10:45 PM PDT
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Thursday, May 30, 2019

Why did the Fukushima nuclear plant switch to using fresh water after the accident?

Why did the Fukushima nuclear plant switch to using fresh water after the accident?

Why did the Fukushima nuclear plant switch to using fresh water after the accident?

Posted: 29 May 2019 06:45 PM PDT

I was reading about Operation Tomodachi and on the wikipedia page it mentioned that the US Navy provided 500,000 gallons of fresh water to cool the plant. That struck me as odd considering they could just use sea water. After doing some digging this was all I could find. Apparently they were using sea water but wanted to switch over to using fresh water. Any idea why?

submitted by /u/scrubs2009
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Will age/time work differently for a colony on Mars than it would on Earth/would a person be younger/older on one versus the other?

Posted: 30 May 2019 07:04 AM PDT

A common symptom of severe radiation exposure is nausea and vomiting shortly after. What biological mechanism is affected by the radiation to result in these symptoms so soon after exposure?

Posted: 29 May 2019 09:29 PM PDT

This is a well-known effect of severe exposure to radiation. I've been searching online to find out what specific biological process is disrupted by the radiation to produce this effect, but I haven't found anything.

I can understand the biological origin of the many longer term effects due to tissue damage, like hair falling off and diarrhea, due to the damage of the rapidly reproducing cells. But it is unclear to me why nausea and vomiting would have a much quicker onset (minutes in some severe cases recorded) via the same mechanisms. Is a destruction of the cells in the stomach lining really all there is to it, and we're just more sensitive to it?

What kind of biological mechanisms induce nausea/vomiting, and how are they affected by radiation?

submitted by /u/lucasvb
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Does each percent of your phone battery last the same amount of time or does it drain faster as it approaches 0%?

Posted: 30 May 2019 07:26 AM PDT

This may be a dumb question because the word "percent" would imply equal parts UNLESS it refers a portion of the battery that is charged, meaning that some portions could last longer than others, if that makes sense.

It may all just be confirmation bias, but I always feel that my phone battery drains insanely quickly during that last 15-20% while it doesn't drain as quickly off a fresh charge.

Lastly, I've always heard that battery technology was moving at a snail's pace yet lately I've been hearing about phones charging to 50% in 20 mins. I'm assuming that the remaining 50% takes longer than 20 mins to charge, which is another reason I feel like each "percent" on my battery could last different amounts of time.

submitted by /u/HAQERIF
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How long after death can frogs be electrostimulated?

Posted: 30 May 2019 06:42 AM PDT

I'm running a lab in which students will dissect frogs and electrically stimulate their legs to move. I chose frogs because I know they better retain internal ions and energy after death, but I don't know for how long. Live frogs aren't in season, so I'm not sure if I can still run the lab with preserved specimens. Google hasn't been much help and I'm hoping there's someone here who can answer my question.

submitted by /u/Apollo009
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Why do fruits bruise? Why does the bruised flesh taste different from the rest?

Posted: 30 May 2019 07:51 AM PDT

How do submarines keep from rolling underwater?

Posted: 30 May 2019 12:37 AM PDT

So this question kinda has two parts

First, how does the submarine resist the force of water moving laterally along it?

Second, in most animations that I've seen, submarines have a single turbine that propels the craft forward, however with my background knowledge of helicopters and how the tail prop keeps it from spinning in air, how does a submarine prevent this effect in the water?

submitted by /u/FragileEclipse
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How are nuclear cores set up and eventually removed if they are so radioactive? Are they less radioactive at these points?

Posted: 30 May 2019 06:12 AM PDT

Just trying to imagine how you could even use machinery to regularly place and remove the cores if they're as dangerous as damaged open cores. How often are they replaced?

submitted by /u/esheena1
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Is it possible to transmit composite/coaxial tv over fm radio?

Posted: 29 May 2019 08:11 PM PDT

If you windmill your arms in outer space, do you rotate or do you stay stationary?

Posted: 29 May 2019 09:30 PM PDT

What drives stellar nurseries to expand outwards and the stars to separate instead of remaining in a cluster?

Posted: 30 May 2019 02:21 AM PDT

During this expansion of a stellar nursery, do some stars collide into each other and form black holes and if not why?

submitted by /u/alleax
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If a Thermos flask maintains heat by blocking conduction/convection by means of a vacuum gap in its walls, does that mean sound is also unable to travel through the walls?

Posted: 29 May 2019 09:42 PM PDT

I don't have a small enough speaker to do an 'experiment', but would a source of sound be inaudible to an outsider if placed in a closed Thermos flask?

I suppose it depends on whether the vibrating atoms can bridge the gap, which in turn depends on the amplitude of the source -- but if the gap was big enough, then surely there would be no feasible way to make a sound source that can escape the Thermos?

submitted by /u/_PrimalDialga
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Is it possible to artificially induce strong intermolecular forces?

Posted: 30 May 2019 05:00 AM PDT

I was just wondering if you could create an appliance which temporarily combined gases in the air into a solid to make an "air" step.

submitted by /u/kuuhaq
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Do high radiation levels have any immediate, short-term, and long-term effects on human memory formation and cognitive abilities?

Posted: 30 May 2019 04:35 AM PDT

What does zero point energy mean and how does it correlate to quantum physics?

Posted: 29 May 2019 10:25 PM PDT

I've looked up what zero point energy means but still do not understand what it really means. To my understanding it's relating about minimum energy of the universe and the energy of a proton?

submitted by /u/RedmeisterR
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Do photons have any mass or they just have no mass at all?

Posted: 29 May 2019 01:32 PM PDT

If they do have some minimal mass, could a "photon engine" work in a fantasy spacecraft where it just blasts a powerful laser backwards to get propulsion?

submitted by /u/Morke_
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Is there a difference between how information and experiences are remembered?

Posted: 29 May 2019 05:15 PM PDT

This is question popped into my head after I noticed that I seem to be able to remember and recall information, facts, and knowledge really easily, but events and experiences always seem to be much more fuzzy in my memory. So, I was wondering if there were any notable differences in the storage, maintenance, and recollection of these things.

submitted by /u/Alice_Because
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Special Relativity question too long for title (see text)?

Posted: 29 May 2019 07:52 PM PDT

You shine light on X Axis to both sides. For Say 10 seconds.

They both Travel 10LightSeconds Distance. Total 20LS. To each opposite photons doesn't it look like the opposite photons are going 2xLS?

I was trying to explain it in my head that perhaps light doesn't experience time. (Which I believe is true). So sub it with any object that travels at speed > 0.5 LS

submitted by /u/toseawaybinghamton
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Can telescopic images taken during the Earth's orbit around the sun be peiced together similarly to those taken by the network of telescopes around Earth, which were used for the recent black hole images?

Posted: 29 May 2019 06:14 PM PDT

The Event Horizon Telescope is a network of international telescopes which collected data that was peiced together (through a process called interpolation) to create the recent black hole images. A much larger area is covered by the Earth's orbit around the sun, so would a similar process be possible to look much further? If so, would the view for this be limited to a perpendicular line through the flat plane of Earth's orbit?

submitted by /u/psych_student_
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Physics of archery: Does it matter if the bowstring is loose at the end of release?

Posted: 29 May 2019 11:05 AM PDT

I made a giant 4 armed ballista (scorpion?) inspired by the giant one in game of thrones. Here is a youtube video for reference. https://www.youtube.com/watch?v=2ReBMjJU7vc (the part relevant to my question is at 3:50)

A lot of comments saying I would have better performance if the bowstring was taut on release. Right now the string is 'loose' on arrow release.

I just figured if I pulled it back until it reached 1000 pound draw, the springs would be storing the same about of energy, but the draw would be longer because the string was not tight to begin with.

My argument against the making string tight to begin with is simple design. Mainly due to having to bend the limbs back enough to clear the mounting plate for the limbs. And for example say it would be loaded with around 200lbs of force bending the arms back. Then if I pulled the arrow back to 1000lbs, there would only be 800lbs of force available to act on the arrow.

Im just wondering if there is an advantage to have the limbs and bowstring tight and under tension at the release point, and why this is so. Thank you!

submitted by /u/MerlinTheWhite
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Are Black Holes Magnetically Active and If so How is the magnetic field produced?

Posted: 29 May 2019 06:38 AM PDT
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