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Tuesday, September 6, 2016

If e=mc^2, does that mean that the sun is constantly losing mass through radiated energy?

If e=mc^2, does that mean that the sun is constantly losing mass through radiated energy?


If e=mc^2, does that mean that the sun is constantly losing mass through radiated energy?

Posted: 05 Sep 2016 01:01 PM PDT

Assume that there is no ejected particles, just emitted radiation. Would such a body be losing mass?

submitted by /u/tylerchu
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If elements above 83 (+43, 61) are all man made, is it strictly impossible for them to appear in nature?

Posted: 05 Sep 2016 02:17 PM PDT

Watching some Scishow talk about the 'end' of the periodic table and wondering if it was impossible for these supermassive atoms to exist on their own (if, perhaps, for a fraction of a second)

submitted by /u/Ryutauro
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What are the physics behind Iron being the threshold of endothermic/exothermic nuclear fusion/fission?

Posted: 06 Sep 2016 03:34 AM PDT

In most photos of galaxies there seems to be a bright central core. Is that just some giant star or a huge mass of them?

Posted: 05 Sep 2016 12:13 PM PDT

this is just some thing I have noticed looking at all the gorgeous images we have from the Hubel telescope.

submitted by /u/b3anspud
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If the speed of light varies according to the "medium" it travels trough, fastest being "vacuum", is it theoretically possible that it could be more than 299792458 m/s in some "theoretical exotic medium"?

Posted: 05 Sep 2016 07:49 PM PDT

Apparently vacuum means "void of matter". But apparently, matter makes only about 5% of the Universe.
Dark matter makes up about 25% of it and dark energy about 70%.

What if we could have a "medium that is void of matter AND void of dark matter?

Or since matter is just another incarnation of energy, what about "medium" void of matter, dark matter AND dark energy, let's call it "dark vacuum" (trademarked by u/asmj)?
Wouldn't it be, at least theoretically possible that "c" could be greater than in "ordinary vacuum"?

submitted by /u/asmj
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For an extinction event-sized meteorite (e.g. the one that caused the Chicxulub crater, ~10km), how long would the object be visible in the sky before impact?

Posted: 05 Sep 2016 08:32 AM PDT

How does gene therapy/crispr affect every single cell in the body?

Posted: 05 Sep 2016 02:50 PM PDT

Whether its by a viral vector or crispr, I understand how they alter DNA but I don't know how they manage to get delivered to every cell. If one cell is altered, does the genome of every cell change? What exactly happens?

submitted by /u/Jnicky69
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Are roaches in human dwellings more, less, or just as common today as in the past?

Posted: 05 Sep 2016 09:07 PM PDT

What is the estimated size of proto-Earth before it was impacted by Theia?

Posted: 05 Sep 2016 04:56 PM PDT

In the 'empty universe' thought experiment, how long would it take for the two protons to collide?

Posted: 05 Sep 2016 11:49 PM PDT

I've seen on Reddit the view that two protons say 14 billion light years apart but in an otherwise completely empty universe would eventually collide through gravitational attraction.

Is there a way to coherently calculate how long that would actually take? Let's say they're initially motionless relative to one another. Perhaps longer than things like spontaneous quantum tunnelling to occur (see https://en.m.wikipedia.org/wiki/Timeline_of_the_far_future - one of my favourite wiki articles)

Doesn't the above imply that the gravitonal field of each extend for 14 billion light years (and therefore perhaps infinitely)?

Is the effect somehow instantaneous or would it presumably be subject to the speed of light?

I love this sort of stuff!

submitted by /u/rasputinny
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Does mass increase when temperature increase?

Posted: 06 Sep 2016 02:35 AM PDT

To heat water (ignoring mechanical forces and phases transitions), you have to give it energy:

E = M Cp dT.

But energy is also mass:

E=mc².

So does the mass of a body isolated from the outside gain mass when heated?

I did the maths for 1000m3 of water, the supposed mass variation from 10°C to 90°C is 3.7 mg. I guess it is big enough to have been measured with something more stable than water.

submitted by /u/wawatsara
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So the sun has been 'burning' for billions of years and has a couple billion left, what is it that keeps all this fuel in one place for such a long time in such a stable formation? Why doesn't it all just explode or break itself apart or do something else in a small amount of time?

Posted: 05 Sep 2016 04:43 PM PDT

Is it just the gravity and balance of the whole system that keeps bringing the 'spare' hydrogen into the centre much like throwing logs on a fire? If the gravity is keeping all the hydrogen in a big ball, why doesn't it all react at once or very quickly?

submitted by /u/MikeW86
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Why, after it has been raining, is there nearly always very dense mist over forested areas?

Posted: 06 Sep 2016 01:00 AM PDT

There is quite a large forest near my house on some mountains, and whenever there is rain I can always see very thick mist/fog over the forest.

Is this to do with transpiration or something else?

submitted by /u/TheSentinelsSorrow
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Is there a correlation between the quality of water people drink and the amount of kidney stone cases?

Posted: 05 Sep 2016 08:39 PM PDT

I recently joined a research team at my university. We are studying the water quality in different parts of South Carolina and how/if it relates to the number of kidney stone cases. We are mainly concerned with the "hardness" of the water, or the amount of calcium and magnesium. I have seen studies online that have concluded that less calcium in a diet actually leads to more cases of kidney stones, which I was surprised by. Does anybody have an explanation for this, or have any insight to help us with our study? Thanks

submitted by /u/TheScottishWarrior
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What is the hilbert space of two interacting systems?

Posted: 05 Sep 2016 09:44 AM PDT

Is the hilbert space of a system which consists of two intertacting subsystems the tensor product of the hilbert spaces of each subsystem? I would think not, since the elements in such space represent all the possible combinations of states of both systems. Is it a subspace of such space? Is it something completely different?

submitted by /u/Paul-Lubanski
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How do railguns work?

Posted: 05 Sep 2016 12:26 PM PDT

I know that railguns use magnetism and something called the Lorentz force to propel things but how exactly does that all happen? Does anyone have any papers on it?

submitted by /u/GeneralEMP
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How representative is the composition of our solar system versus the composition of known exoplanets?

Posted: 05 Sep 2016 12:46 PM PDT

For instance, is a large gas giant like Jupiter representative of other gas giants? Are gas giants typically located towards the out portions of the solar system? Do rocky planets tend to have atmospheres like Venus and Earth or is Mars a more representative example?

submitted by /u/AnabolicHippo
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How many trees would I have to plant to offset the carbon dioxide emissions of a 24 hour plane trip?

Posted: 05 Sep 2016 09:14 AM PDT

If I had a pane of diamond thick enough, would the world appear to be moving slower as I looked through it?

Posted: 05 Sep 2016 08:55 PM PDT

I recently learned about refractive indices and their correlation to the reduction of the speed of light through a specific medium in a vacuum. Through some quick research, I discovered that diamond has a refractive index of 2.42, and that puts the speed of light at 59% slower as it travels through the diamond. So as my question desires: would it be possible to view "real-time" through a pane of diamond and have it appear at a slower pace? How thick would that pane of diamond need to be and is there an equation to calculate it? Or would the pace of "real-time" still appear the same, only it reaches the other end of the diamond pane at a later time?

submitted by /u/DrMrEggman
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Monday, September 5, 2016

Why haven't the colors on Jupiter all mixed together yet?

Why haven't the colors on Jupiter all mixed together yet?


Why haven't the colors on Jupiter all mixed together yet?

Posted: 04 Sep 2016 06:54 PM PDT

Shouldn't it just be one big grey ball by now? What's separating the colors?

submitted by /u/SamSlate
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If I am swimming in the ocean when lightening strikes, how far away do I have to be to not get hurt and why?

Posted: 04 Sep 2016 03:18 PM PDT

For some reason I'm at the beach on vacation and this is all I can think about

submitted by /u/RobisaII
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If charged particles that are stationary are electric, those that move uniformly are magnetic, and those that accelerate emit radiation, what happens with those that jerk or snap?

Posted: 04 Sep 2016 10:27 AM PDT

Jerk and snap being the first and second derivatives of acceleration with respect to time.

I don't know how to categorize this post on my mobile phone. It's physics obviously

submitted by /u/ktool
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A doctor will clean an injection site before giving a shot - why doesn't a dentist need to do so before a numbing shot? Don't our mouths generally have more bacteria than our arm/leg skin?

Posted: 04 Sep 2016 03:14 PM PDT

or does the topical anesthetic they use before the needle also contain an antibiotic? Or is the bacteria in our mouths less dangerous because it's more "internal" and our bodies are already used to it?

submitted by /u/PM_ME_YOUR_NOSE_HAIR
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Since I have never seen it, I'm assuming it cant be done properly. Why do we not see people jumping out of airplanes with a super reinforced umbrella? Basically Mary Poppins style? What would happen is someone could build such a contraption and actually tried the jump?

Posted: 04 Sep 2016 11:38 PM PDT

In the long run, is worldwide income/wealth inequality increasing, decreasing, or fluctuating around a mean?

Posted: 05 Sep 2016 06:54 AM PDT

Looking throughout the course of human history, there seem to be forces that both increase and decrease economic inequality. Is any side dominant so far or do they both meet each other at an equilibrium? What about in the future? Do we know?

submitted by /u/nebeeskan2
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When the skin is grazed in such a way that there is no bleeding, a different fluid leaks out of the wound that is a pale yellow and foul-smelling. What is this fluid and why is it leaking?

Posted: 05 Sep 2016 05:12 AM PDT

I recently severely grazed my head and so much of this fluid came out that it formed a large glue-like orange crust that smelled disgusting and was painful to remove.

Some sites on the internet say its blood plasma, but why would blood plasma leak out and not also blood? Other sites say it is white blood cells which is ridiculous. The most likely answer I found was that it's a combination of intra-and extra-cellular fluid leaking from skin cells torn open by the graze. I'd much appreciate if ask science settled this issue.

submitted by /u/trump_is_antivaxx
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What makes the air in old enclosed spaces smell 'stale', regardless of whether humans inhabit it?

Posted: 05 Sep 2016 02:32 AM PDT

What would happen if I had a wire circuit that stretched to the moon and back and connected it to a battery and a switch. Would there be a delay when I turned it on? How is it possible for that info to move faster than light?

Posted: 04 Sep 2016 12:25 PM PDT

Why are the leads of electronic components never made out of copper?

Posted: 05 Sep 2016 03:14 AM PDT

I get that copper can get brittle after bending it multiple times but wouldn't it provide less resistance and would be more practical in most or atleast some cases?

submitted by /u/lyzux
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What was the primary reason for higher levels of atmospheric O2 500-200 million years ago?

Posted: 05 Sep 2016 06:43 AM PDT

Why does light from houses from outside appear to be yellow, while when inside they seem to give off a white light?

Posted: 05 Sep 2016 12:44 AM PDT

Would an asteroid, close enough to the sun and in the right spot, be able to block all light on Earth, if even for a millisecond?

Posted: 05 Sep 2016 06:20 AM PDT

Or does light somehow wrap itself around the asteroid (or another planet), making it absolutely impossible to tell the difference?

submitted by /u/BruceElMoose
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What are the uses of helium?

Posted: 05 Sep 2016 06:06 AM PDT

Not including balloons and to make funny voices.

submitted by /u/AsmundH
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What would happen if you stood on Jupiter's surface?

Posted: 04 Sep 2016 09:48 AM PDT

Why does hydrogen peroxide foam when it comes in contact with a cut but not unbroken skin or other surfaces?

Posted: 04 Sep 2016 11:45 PM PDT

I recently cut myself quite badly in a Kitchen accident. Ultimately, I ended up needing stitches. When I first injured myself I was quick to clean the wound. I had hydrogen peroxide in my medicine cabinet, so I used that to clean the wound. I've used it in the past but never on a cut of this size. This was the first time that I noticed that hydrogen peroxide foams along the contours of the cut; however, it didn't foam any where else, including the surface of the sink, which was covered in blood. So why does it foam on my cut?

submitted by /u/MZ603
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If a wheel that is a perfect circle (eg 10cm radius) travelled along a perfectly flat road how much of the wheel is touching the road at any point?

Posted: 05 Sep 2016 05:28 AM PDT

Also, does the diameter of the circle change the amount of contact?

submitted by /u/Barrakus
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Why do two wind turbines close to each other turn at different speeds or one not turn at all?

Posted: 05 Sep 2016 01:41 AM PDT

In the winter, I can see two wind turbines from my house (the big kind). They often turn at different speeds or one is not turning at all. At wind farms I pass, it seems similar - I rarely see them all turning together. Sometimes, they will seem to be at radically different angles to each other too.
Is this related to matching demand or is one being serviced?
I understand there is a cost to starting up a turbine. What form does that take, and why?
If two turbines are turning at different speeds, is the faster one generating more electricity? Do the turbines have 'gears'? Thanks!

submitted by /u/yoosanaim
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Do we have medicine's which are able to target receptors in specific areas of the body?

Posted: 05 Sep 2016 05:09 AM PDT

I.E. Androgen receptors in the scalp. A medicine to target only the androgen receptors.

submitted by /u/ecgsmithy
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What is the highest resolution neuroimaging technique available today? What resolution can we expect in the next years?

Posted: 05 Sep 2016 04:44 AM PDT

My understanding is that the resolution is still really low and far from separating individual cells. Is there an effort to extend this? And is it actually realistic that it will ever be possible to have a non destructive imaging technique that would allow for later brain simulation?

As far as I know brain simulation models currently rely on electronic microscope data and the studied brain is generally destroyed during the procedure.

submitted by /u/evotopid
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How are precious stones like diamonds and sapphires lab grown?

Posted: 05 Sep 2016 12:56 AM PDT

Sunday, September 4, 2016

If fizzy drinks were made with another gas besides CO2 like argon or helium etc, how would the drinks taste different?

If fizzy drinks were made with another gas besides CO2 like argon or helium etc, how would the drinks taste different?


If fizzy drinks were made with another gas besides CO2 like argon or helium etc, how would the drinks taste different?

Posted: 03 Sep 2016 02:06 PM PDT

EDIT: Thanks for all the great answers. I've never really paid attention to the "Nitro" drinks before. I though Nitro was just a marketing tagline for ENERGY.

Now i'm going to start a Kickstarter for my new cabbage flavored energy drink with methane gas!

THANKS

submitted by /u/oppleTANK
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Why is 90% sulfuric acid more corrosive than 99% sulfuric acid?

Posted: 04 Sep 2016 12:18 AM PDT

I tried doing some research on this but the only reason I can find that explains this is that 90% acid has a higher water content. However, that is not too clear to me why the extra water content affects corrosion.

submitted by /u/Acidman00
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Why don't Game or simulation engines us spherical coordinates instead of x,y,z and what would its effect be on floating point numbers?

Posted: 04 Sep 2016 03:14 AM PDT

Can someone please explain the criticisms of the Myers/Briggs personality test?

Posted: 03 Sep 2016 09:37 PM PDT

I was recently asked to take the test. I was given the INTJ type and when I read the description I felt it was accurate, however I couldn't shake the feeling that this is just a modern day horoscope. So is this test widely accepted? What are the valid criticisms against it?

Edit: Thanks for the answers, folks. You were able to put some of my feelings into words much better than I could.

submitted by /u/killthebadger
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Why are there no hi-res images of the north or south poles?

Posted: 04 Sep 2016 06:44 AM PDT

Google maps doesn't seem to display them well either, so I'm curious what's the reason for this.

submitted by /u/harksha
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Do things cool off in space?

Posted: 03 Sep 2016 08:02 AM PDT

I'm sure this is a stupid question but if there is no matter in the void of space to get the heat transferred to, wouldn't a hot thing sent to space just remain hot?

submitted by /u/sinkezie
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How fast would one need to accelerate a container of air to make it bunch up to one side, creating a vacuum on the other?

Posted: 04 Sep 2016 04:59 AM PDT

Back when railroads were new, alarmists feared that the speed of the carriages going as fast as 20mph would create a deathly situation for the passengers. This was obviously quite wrong. But how quick of an acceleration WOULD be needed to start heaving the air in a contained space over to one side of it?

submitted by /u/thetzar
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How can a B-2 spirit have directional stability, since it has no vertical tail?

Posted: 04 Sep 2016 03:31 AM PDT

What does the wave function Ψ look like for an hydrogen atom?

Posted: 03 Sep 2016 08:45 AM PDT

My understanding is that you obtain the wave function for a system by solving the Schrodinger's equation for that system (I apologize if I'm actually basing my question on a wrong premise). So, assuming the system is a simple hydrogen atom in it's ground state, what would the wave function look like? And for a hydrogen molecule in the ground state?

I'm asking this because even though I was reading about this stuff, I never actually saw the wave function itself.

Thanks!

submitted by /u/Lichewitz
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Why did humans evolve to have different blood types?

Posted: 03 Sep 2016 07:15 PM PDT

It must serve some purpose.

submitted by /u/2smartt
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Why is it so difficult to put on pajama bottoms right after you get out of the shower?

Posted: 03 Sep 2016 11:44 PM PDT

At what point in the Juno mission will we have a clear understanding of the composition of Jupiter's interior, including its core?

Posted: 03 Sep 2016 06:36 PM PDT

How are natural satellites discovered?

Posted: 04 Sep 2016 07:28 AM PDT

What is the process of discovering natural satellites around planets?

I was browsing moons when I noticed that bigger planets have tons of smaller moons. I then noticed wikipedia has images of these satellites and one of them was named ["Discovery image of Hermippe"]. How does scientist determine from this one little white speck that it is orbiting Jupiter? How does speck in image become verified discovery? How does the scientist even know he has discovered something new?

Edit: Url for image. Reddit doesn't seem to like () inside url. https://en.wikipedia.org/wiki/Hermippe_(moon)#/media/File:%CE%95%CF%81%CE%BC%CE%AF%CF%80%CF%80%CE%B7.gif

submitted by /u/ssg-
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Is there a gene that all cells have a form of and could not live without? is there a most common gene across the domains?

Posted: 03 Sep 2016 09:28 PM PDT

Which planet in our solar system is the oldest/youngest?

Posted: 04 Sep 2016 07:11 AM PDT

Whats up with all the earthquakes lately? Is this normal?

Posted: 03 Sep 2016 07:16 PM PDT

Maybe Im crazy but it seems like there have been a ton of earthquakes lately, like the one that just happened in california or oklahoma today. Its really starting to freak me out. Is this normal or should I be worried?

submitted by /u/susbot27
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Why do magnetic lines of force tend to contract?

Posted: 04 Sep 2016 06:11 AM PDT

In baking, does it really, from a scientific and chemical perspective, matter if I mix the dry ingredients separately?

Posted: 03 Sep 2016 07:38 PM PDT

Why do parallel lines meet at infinity?

Posted: 03 Sep 2016 11:09 PM PDT

I thought that the very definition of parallel lines were that they were to always remain at the same distance apart, but i've heard that at infinity this is not the case and in fact they do meet.

submitted by /u/zayde199
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Are there caves on the moon?

Posted: 04 Sep 2016 12:58 AM PDT

Perhaps from some kind of porous origin or undetected (but unlikely if not impossible) flowing water underneath the surface? I know most Earth caves are from active erosion.

submitted by /u/JasontheFuzz
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I recently saw this Facebook video about the pH of various brands of drinking water. What is the difference between drinking acidic water and alkaline water? Is the acidic water harmful as they say it is or is it a hoax?

Posted: 03 Sep 2016 07:54 PM PDT

If neurotransmitters can be either excitatory or inhibitory why is there not just two neurotransmitters?

Posted: 03 Sep 2016 10:58 PM PDT

I have read that having lots of neurotransmitters adds complexity to the signal but I dont understand how. Because the action potential is either fired or not fired. If possible could you provide an example that shows why 2 neurotransmitters would not work.

submitted by /u/-Silver-Tongue-
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What is the difference between kinetic and static friction?

Posted: 03 Sep 2016 08:21 PM PDT