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Sunday, September 17, 2017

What is the gold and silver foil they put on satellites and why is it important?

What is the gold and silver foil they put on satellites and why is it important?

What is the gold and silver foil they put on satellites and why is it important?

Posted: 17 Sep 2017 04:32 AM PDT

I was looking at a picture of a satellite in the news the other day and noticed that every time I've seen some kind of space-related piece of equipment, it is wrapped in gold/silver foil. Is this real gold and real silver? What is it? Why is it used?

Thank you!

submitted by /u/BarSeraph
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Would it be possible to slow light down enough for the naked eye to see it moving?

Posted: 17 Sep 2017 01:07 AM PDT

Light moves 66% of c in water. Would it be possible to create a liquid(other states of matter also count) in which light moves so slowly so that it's visible with the naked eye?

An example: Let's say that we have a curtain of said liquid. If I stand on one side of it, and quickly am to walk to the other side, and looked through the curtain, would I then see a past reflection of myself, one which stands on the other side of the curtain?

submitted by /u/blackcarpet2000
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Did NASA nuke Saturn?

Posted: 16 Sep 2017 03:35 AM PDT

NASA just sent Cassini to its final end...

What does 72 pounds of plutonium look like crashing into Saturn? Does it go nuclear? A blinding flash of light and mushroom cloud?

submitted by /u/Gbltrader
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Can wave functions of two particles completely cancel eachother out, in the same way as noise cancelling?

Posted: 16 Sep 2017 06:17 PM PDT

How does adding heat to a liquid allow it to dissolve more substance? What effect does heat have on whatever IMFs are at work.

Posted: 17 Sep 2017 03:29 AM PDT

If a solid is clumping to itself while surrounded by liquid, it probably means the solid molecules have greater IMFs between themselves than with h20 (what about if they're just pressed together? E.g a pill. I'm not sure). Heat means more kinetic energy in the water built that's where I can't bridge the understanding gap

I haven't had a fun chem question like this in a while, brings me back to muh roots

submitted by /u/thetrapjesus
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What would hurt more saltwater or freshwater?

Posted: 17 Sep 2017 06:11 AM PDT

If you were to jump into a freshwater lake vs jumping into salt water, will the impact be harder on your body for one or the same for both?

Hypothetically if you could replicate both jumps from the exact same height, landing the exact same way and both bodies of water were the exact same temperature

submitted by /u/joshbvl
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What function does natural oil have as a part of the eco-system?

Posted: 16 Sep 2017 11:51 PM PDT

Where do the abs go during a pregnancy? Up, down, front, back?

Posted: 16 Sep 2017 01:23 PM PDT

How do you determine the oxidation states of transition metals?

Posted: 16 Sep 2017 04:18 PM PDT

I know that a lot of the transition metals have oxidation states of +2 and +3, but I was never taught what determined them, and it seems pretty random. My teachers just told me to memorize each transition metal

submitted by /u/iliedabouthewheels
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Why can't we objectively & accurately test the spice level, &/or capsaicin amounts in a given product?

Posted: 15 Sep 2017 07:19 PM PDT

The scoville units don't seem to be the most scientific approach to determining spice level. We have nutrition labels, we determine alochol, caffeine, THC, & OTC med content level. Why can't we test objectively & accurately the spice level of foods?

submitted by /u/ralphwiggum420
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How does petrol "get old" in a container?

Posted: 16 Sep 2017 08:29 PM PDT

Discovered today that petrol, even if it's in a decent container, gets "old" and loses combustability. You can also get additives to prevent this. What's going on and what do the additives do?

submitted by /u/dasfreak
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Magnetic field disappearance in the reference frame of a moving charge before special relativity?

Posted: 17 Sep 2017 12:08 AM PDT

If a charged particle is moving steadily, there is an associated magnetic field. However in the reference frame of the particle, the magnetic field disappears. It's naturally reconciled if you consider relativistic contraction, but I'm curious how physicists approached the problem before the advent of special relativity/ Lorentz transformations.

submitted by /u/Im_int
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There are Glasses that make Colorblind People see colors. Do they work the other way around too?

Posted: 15 Sep 2017 02:40 AM PDT

What happens if "normal" people wearing them? Do they see B&W? Could the glasses be modified to do so?

Edit: I know Colorblind people don't see B&W. It was a metaphor because there are so many different ways of colorblindness.

submitted by /u/hdrr_at
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Why do the bottoms of clouds seem to be flat while the tops seem to be very bumpy?

Posted: 16 Sep 2017 02:39 PM PDT

Does nuclear waste produce energy?

Posted: 16 Sep 2017 08:12 AM PDT

Might be a stupid question, but I was thinking that if it could produce energy, we could use it as an RTG and blast it off into space.

submitted by /u/thosedamnpiggles
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What is under Saturn's clouds?

Posted: 16 Sep 2017 08:34 PM PDT

I could never really understand what's under Jupiter's and Saturn's gases. You could see meteor strikes [I remember a while ago, a series of huge asteroids hit jupiter and you could see the black spots from them], yet I still can't understand how that can be visible if there are such thick gases on its surface.

submitted by /u/crescent_reincarnate
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How and when does brain and nervous system turn on in human fetus?

Posted: 16 Sep 2017 11:30 AM PDT

What are the actually formulas of the Trigonometric functions?

Posted: 17 Sep 2017 12:48 AM PDT

In other words, what is the sine inverse function actually doing to in the equation "sin-1 (17/23)" to turn 17/23 into 47.65739... degrees? Also, the other way around: If I had sin(47.65739°), what is the sine function doing to turn that angle back into a ratio? is there a specific formula that each one has?

submitted by /u/MajorLeagueRekt
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Quantum Physics, How many states can matter be the superposition of at once?

Posted: 16 Sep 2017 11:11 AM PDT

Schrodinger's Cat was Dead/Alive. Could it have also been Dead/Alive/Maimed in a similar scenario? is there a limit to the superposition?

submitted by /u/bubsd
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What happens if a white dwarf is accreting mass slowly until he reaches the tipping point to become a neutron star?

Posted: 16 Sep 2017 07:14 AM PDT

So i am not talking about a merger of two white dwarfs for example, which i know are violent events. More like a slow procress like syphoning matter from a binary partner. How violently would such a process happen? Is there some kind of supernova happening when the dwarf collapses?

Bonus question: what happens if a neutron star amasses matter slowly and turns into a blackhole?

submitted by /u/katzmarek
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What if you sprayed a hydrophobic solution (UltraEverDry, NeverWet) onto water?

Posted: 16 Sep 2017 03:52 PM PDT
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Saturday, September 16, 2017

AskScience AMA Series: I am Dr. John Nagy and I'm here to talk about Peto's Paradox and why larger mammals don't have higher cancer rates. Ask Me Anything!

AskScience AMA Series: I am Dr. John Nagy and I'm here to talk about Peto's Paradox and why larger mammals don't have higher cancer rates. Ask Me Anything!

AskScience AMA Series: I am Dr. John Nagy and I'm here to talk about Peto's Paradox and why larger mammals don't have higher cancer rates. Ask Me Anything!

Posted: 16 Sep 2017 07:22 AM PDT

Hello Reddit! I'm a mathematical biologist (@jdnagy96) studying why larger mammals don't have higher cancer rates--like why aren't all blue whales dying of cancer? This is just one of the many questions about cancer that evolutionary theory helps illuminate. We also work on how evolution causes tumors to become malignant and resist treatment. I'll be around in the afternoon (ET), so AMA!

submitted by /u/AskScienceModerator
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Would an Argon-Oxygen atmosphere be breathable?

Posted: 16 Sep 2017 05:01 AM PDT

Could humans breath an Argon-Oxygen atmosphere? For bonus points: what about a Neon-Oxygen atmosphere?

submitted by /u/VirtualArmsDealer
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Alpha and Beta rays can barely get through a sheet of paper, How much mass do you need to block gamma rays?

Posted: 15 Sep 2017 01:20 PM PDT

Cassini was launched in 1997, how come the photos it send back are HD on par with 2017?

Posted: 16 Sep 2017 12:28 AM PDT

What's the amplitude of a electromagnetic wave ?

Posted: 16 Sep 2017 05:58 AM PDT

Last day, in physics class, I learnt that mechanical waves have an "Amplitude". I wondered if an electromagnetic has one, and then what could be its value. (sry for my English )

submitted by /u/Ezatrixx
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Can atoms give up electrons that are not in the outer layer?

Posted: 16 Sep 2017 04:33 AM PDT

There is no way for it to happen naturally that I know of, but can we force, for example Sodium, to not only give the one aelectron in its third outer layer, but to also give additional electrons from its second layer?

submitted by /u/MrZipZap
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Is there a logical reason as to why both variance and standard deviation are used?

Posted: 16 Sep 2017 06:20 AM PDT

Given the mathematical relationship (squaring and square rooting) between the two of them, how come the other exists? Can't we just use standard deviation for everything, and in formulas just square the standard deviation?

submitted by /u/nintendogedsi
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What happens to the energy in a Mains to USB adaptor?

Posted: 16 Sep 2017 04:41 AM PDT

I suspect this could be generalised to any power brick. But here's what I know.

Mains voltage runs at 240/250V (atleast here in the UK). The plug will have a transformer in it that steps the voltage down to the 5V necessary for USB compliance.

Electricity flows when a circuit is complete. The input to the transformer forms a complete circuit; and when a device is connected to the output a current will be induced in the output of the transformers coil as that is also a complete circuit.

But when a device is not connected to the output where is the energy from the completed input circuit going?

submitted by /u/innerlambada
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On Earth like planets (water/rock) would supercontinents be the norm? Or would we see most planets with fractured continents like present day earth?

Posted: 15 Sep 2017 09:33 PM PDT

Is it possible to touch solid light?

Posted: 15 Sep 2017 06:46 PM PDT

I've been reading up on how scientists in 2014 forced light into a solid state, articles referring to them as creating light crystals.

My question is, if all contact between regular matter is electrons within atoms pushing other atoms away, would it be possible for someone to touch a material made out of photons and if not how would regular matter and light crystals interact if they came into contact with each other?

submitted by /u/BaldEagleFacts
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How to read the table in chapter 7 of "How to Teach Quantum Physics to Your Dog"?

Posted: 15 Sep 2017 05:36 PM PDT

I'm currently reading this 'How to Teach Quantum Physics to Your Dog' by Chad Orzel - which I highly recommend. However, I am stuck in chapter 7. In particular, the explanation about the Bell theorem. I think I am not reading/interpreting the table in that chapter correctly.

For what follows, it helps if you have the book in front of you. However, I'll try to explain what happens in that chapter for those who haven't. Those who have the book can skip to the question below :)

Orzel presents a table that gives the possible outcomes of an experiment, as predicted by Local Hidden Variable Theories, in which two observers each have a photon detector. Each of the detectors is equipped with a polarized filter of which the angle can be varied.

If I understand correctly, a source emits two photons of which the polarization is assumed to be the same (not sure about this, though). The Local Hidden Variable Theories assume that the polarization of both is a fixed value, but unknown.

Now, the table I am talking about lists for each observer (Truman and RD) and each orientation (a,b or c) of the filter, the different possible outcomes (1 = photon detected, 0=not detected). See image

Given that we have 2 possible outcomes and 3 orientations (a,b and c), there are 8 possible states (polarizations?) the photons can be in.

QUESTION

Now, on to the question. To get the predictions for the Local Hidden Variable Theories, we are supposed to determine the chance that Truman (observer 1) and RD (observer 2) measure the same outcome given different settings for the filters (a, b or c). The book states that this probability can not be lower than 33%.

However, the book also states that we can 'play around with the probabilities of the individual states'. For example, the book states, we can avoid states 1 and 8.

If we can select the possible states for the photon, shouldn't we be able to make the chance equal to 0? For example, I would think that if Truman chooses c and RD chooses a AND we make sure that the state is always 2, they should always get different outcomes. What am I missing here?

I really hope that someone can help me out as I think this is the clearest book on this subject I have read. In particular, because Orzel does a good job at explaining the implications of QM.

submitted by /u/Tits4Twats
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Are bananas more radioactive then other foods?

Posted: 15 Sep 2017 06:56 PM PDT

Banana equivalent dose? Can somebody explain this to me? Are they just using bananas as an example or are they more radioactive than other healthy foods? I am paranoid to eat bananas lol.

submitted by /u/pencilpens
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Almost every structure we build contains cement, so when will we run out of the materials to make cement?

Posted: 15 Sep 2017 05:58 PM PDT

Does a MRI affect the iron in the blood in anyway?

Posted: 15 Sep 2017 08:25 PM PDT

Why is it that when you try to focus on 1 star it seems to slowly disappear, and when you focus your eyes just next to the star you see it sharply again?

Posted: 15 Sep 2017 10:26 AM PDT

Could someone help fix my understanding of action potentials and the Na+/K+ pump?

Posted: 15 Sep 2017 06:26 PM PDT

The simplified explanation I was taught goes like this:

Non-gated sodium channels open following a stimulus. Once enough Na+ ions diffuse through these channels (as well as through the membrane to a lesser extent), the electrical charge reaches a threshold of -55mV, voltage-gated sodium channels also open, and the membrane depolarizes until it reaches around 30 mV. At this point, voltage-gated sodium channels close, voltage-gated potassium channels open, and K+ ion efflux repolarizes the membrane to a resting potential of -70 mV, at which point Na+/K+ pumps start to function. However, non-gated potassium channels are still open, and K+ ions are still diffusing out of the membrane through these leak channels, creating hyper-polarization. Na+ is stuck in the axon at this point, as well. The closing of the K+ channels, plus Na+/K+ pump activity, restores membrane charge to threshold, with Na+ ions on the outside and K+ ions on the inside.

This explanation seems pretty flawed to me. The Na+/K+ pump transports 3 Na+ ions out for every 2 K+ ions it transports in. If it kicks in during the refractory period, which is caused by leak channels allowing the escape of positively-charged potassium ions, wouldn't it decrease the membrane's positive charge even further by forcing 3 positively charged ions out for every 2 it pushes in? How does the membrane return to resting potential?

submitted by /u/MemeticMonstrosity
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How does our body get rid of CO?

Posted: 15 Sep 2017 09:35 AM PDT

Everyone knows haemoglobin prefers carbon monoxide over any other gas and that that is why it kills us. So how do our bodies get rid of it if they can't replace it with anything else?

submitted by /u/Heptikbananaz
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How do geosynchronous satellites stay in one place?

Posted: 15 Sep 2017 08:26 AM PDT
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Friday, September 15, 2017

There are Glasses that make Colorblind People see colors. Do they work the other way around too?

There are Glasses that make Colorblind People see colors. Do they work the other way around too?

There are Glasses that make Colorblind People see colors. Do they work the other way around too?

Posted: 15 Sep 2017 02:40 AM PDT

What happens if "normal" people wearing them? Do they see B&W? Could the glasses be modified to do so?

submitted by /u/hdrr_at
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Do non-humans exhibit signs of autism/autism spectrum disorders?

Posted: 14 Sep 2017 06:31 PM PDT

When riding my bicycle, I can stop pedalling, make a 180-degree turn, and the bike still continues moving (though at much lower speed) in the opposite direction. Why?

Posted: 14 Sep 2017 11:29 PM PDT

Momentum is directional and as far as I can see there is no other input energy being applied to the bike (or me), so how can it move in the opposite direction?

submitted by /u/stupid2017
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If electricity from wall outlets is AC, how come some plugs have a left-right orientation?

Posted: 14 Sep 2017 08:07 AM PDT

As in, some plugs have one side bigger, which forces a specific orientation when plugging it into the outlet.

submitted by /u/linearly-independent
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When two neutron stars merge and cause a ripple of gravitational waves, what happens to the objects (planets, asteroids) near the merger?

Posted: 14 Sep 2017 05:16 PM PDT

Do objects get morphed as the fabric of spacetime stretches and shrinks? If a human was close enough, would they feel the gravitational wave?

submitted by /u/Duke_Koch
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Does a Field in Physics always exist (as an expample: the electric field) even when no Particles of that field interact with eachother?

Posted: 15 Sep 2017 01:13 AM PDT

Are there organisms that have characteristics that suggest they are part of a different kingdom of life?

Posted: 14 Sep 2017 05:45 PM PDT

The newest missile launch by North Korea says it reached an apogee of 478 miles. How?

Posted: 14 Sep 2017 05:26 PM PDT

I think this question comes down to my misinterpretation of what the 'altitude' is supposed to represent. It says it reached an altitude of 478 miles. But the altitude of our atmosphere is ~300 miles and the ISS is in orbit at ~254 miles. Clearly I'm not understanding what that value is actually showing so it would be wonderful if someone could clear that up! Here is the article I'm referencing http://www.bbc.com/news/world-asia-41275614

submitted by /u/Aplasmabanana
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Why does enriched uranium explode when blasted into more enriched uranium?

Posted: 14 Sep 2017 05:26 PM PDT

Why does uranium release such a large amount of energy when slammed into more uranium, such as with the Little Boy nuclear bomb?

submitted by /u/Bubbaspiff
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Are the recent record high seismic readings for the Yellowstone Supervolcano anything to be worried about?

Posted: 14 Sep 2017 05:59 PM PDT

Would scientists be able to warn people before it erupted. I'm pretty paranoid about end of the world scenarios.

submitted by /u/Moltenmelt1
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Does evolution work faster for beings with a shorter lifespan since their genes get passed on faster?

Posted: 14 Sep 2017 03:22 PM PDT

Is it possible for the Cassini to take and send some final pictures while entering the surface of Saturn, right before (or maybe even during) it's burning to ash?

Posted: 14 Sep 2017 12:58 PM PDT

Why do we need quantum theories to explain what happens to light with multiple polarization filters ?

Posted: 14 Sep 2017 05:14 PM PDT

Hi,

I just watched a video from YouTube channel minutephysics. It's this video.

The first thing that crossed my mind was - "wait, are you joking me?". Now, don't get me wrong, I'm not here to joke around and I don't want to sound arrogant, but that's exactly what my thought was when I saw them putting a filter between filters like a magician trying to do a trick. I even asked myself - "But why didn't you put a filter over a 90 degree rotated filter and then tell me that it got brighter? Huh? Gotcha!".

Then I watched it until the end, and I realized that they went too far in quantum state of particles and the determinism logic which isn't intuitive to anyone, and that my assumptions were totally based on classical physics or don't need no quantum theories like the entanglement in order to explain to me what happened in the video.

I also jumped to the comments section and I could see a few people asking the same thing, but always getting redirected to how the entanglement doesn't work that way, even though they didn't mention any entanglement at all.

So, this is what I think happens. The logic is very simple.

First, we have 2 filters. The filter A, and filter C. The filter C is rotated 45 degrees, which lets 50% of light, or in other words, blocks 50% of it. We also happen to know that a filter rotated 22.5 degrees (half of 45 degrees), lets 85% of light, or again, blocks 15% of light, which magically is not 25%, but I'll get to it.

Now, when we introduce a filter B, which we put in between filters A and C, we see the light getting brighter. But, if we concluded that filters rotate the wave of light, the filter C is now ALSO rotated 22.5 degrees to the filter B, which blocks only 15%. The math is 15% + 15% = 30%. Of course that it is brighter.

Now, the tricky and the second part is about the thing I said I'll get to it, and what I also wanted to ask reddit. What if the light wave (or filters) are simply not distributed as a standard gaussian distribution model, but they have a slightly smaller variance (the deviation from a standard mean), so that the half from a mean angle gives probability density of 15% and not 25% ?

Wouldn't that explain everything? Why would we need entangled particles, realism and locality to explain this? What am I missing?

submitted by /u/flackjap
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When burning food to see how much calories an item has when there is alot of cellulose (fiber)?

Posted: 14 Sep 2017 06:32 PM PDT

Cellulose (Fiber) doesn't turn into energy in the body but it does burn, asking for a science competition (Food Science)

submitted by /u/Mudkipslaps
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Is it possible to "record" a brain hearing sound and reproduce the sound from the recording?

Posted: 14 Sep 2017 10:03 AM PDT

I was wondering if it's possible to monitor a brain and record whatever it hears and use that to reproduce the same sounds? (More specifically, could you use whatever information you receive to differ from one musical note from another?)

submitted by /u/SjonniBara
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Will Saturns ring form into moons eventually?

Posted: 14 Sep 2017 07:26 AM PDT

If so, how long until the event completes, and how many moons would there be?

submitted by /u/Deadrinker
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Are there any other planets in our solar system that experience totality during an eclipse?

Posted: 14 Sep 2017 10:47 AM PDT

How do all of these NK, ocean-impacting missile launches effect the ocean's biosphere?

Posted: 14 Sep 2017 07:08 PM PDT

How do magnets magnetize other objects?

Posted: 14 Sep 2017 10:38 PM PDT

I left a magnet in a bucket of screws and when I took the magnet out I noticed some of the screws were magnetized and clung to others. How does this happen?

submitted by /u/Bay_Visions
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