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Saturday, January 28, 2017

AskScience AMA Series: I am Sapana V., a cancer biologist who now works with the State Department's Biosecurity Engagement Program. Ask Me Anything!

AskScience AMA Series: I am Sapana V., a cancer biologist who now works with the State Department's Biosecurity Engagement Program. Ask Me Anything!


AskScience AMA Series: I am Sapana V., a cancer biologist who now works with the State Department's Biosecurity Engagement Program. Ask Me Anything!

Posted: 28 Jan 2017 05:00 AM PST

Sapana V. trained as a cancer biologist specializing in inherited risk genetics for acute leukemia. She joined the State Department's Biosecurity Engagement Program (BEP) as a AAAS Science and Technology Policy Fellow in 2015. Her primary BEP responsibilities include setting priorities and implementing programs in several countries in the Middle East and North Africa region, participating in interagency meetings on biological policy issues, and managing BEP's annual budget. In January 2016, she was promoted to Acting Deputy Team Chief for BEP. Prior to joining the State Department, she was a Mirzayan Science and Technology Policy fellow and research associate at the National Academies of Science, Engineering, and Medicine where she helped develop the "Ovarian Cancers: Evolving Paradigms in Research and Care" report. She holds a Ph.D. in Cancer Biology from the University of Chicago and a B.S. in Biology and English from the University of North Carolina at Chapel Hill.

She'll be on starting at 2 PM ET (19 UT)!

submitted by /u/AskScienceModerator
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Is there any physical differences in the brain with an individual with a high IQ number and an individual with an average one?

Posted: 27 Jan 2017 07:34 PM PST

If there isn't any physical differences, how do you differ an individual with a high IQ and an individual with a low one?

And are these differences tied with genetics?

submitted by /u/Just_MyType
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Which is larger, the largest known star in the Universe or the largest known black hole in the Universe?

Posted: 27 Jan 2017 08:02 PM PST

If tomorrow I came up with a way to algebraically solve any nth order, nonlinear differential equation, what would we be able to know that we do not now?

Posted: 27 Jan 2017 04:15 PM PST

Do anti-inflammatory drugs (NSAIDs) prolong infections?

Posted: 28 Jan 2017 07:51 AM PST

So my logic here is that since inflammation is the way the human body deals with pathogens, wouldn't that mean that disrupting this process (for comfort or otherwise) prolongs the infection?

For example fever exists for a reason, so why should we attempt to lower it (if it's in acceptable bounds)?

submitted by /u/JooJoona
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I just saw a post elsewhere about super-massive black holes. What is the SMALLEST mass a black hole could have? Would a single "black molecule" be theoretically possible? An atom? Could a single proton be a black hole?

Posted: 28 Jan 2017 07:28 AM PST

Is poincarre recurrence/eternal return of the universe well accepted? Doesn't a continually expanding universe make it increasingly less likely with time?

Posted: 28 Jan 2017 07:21 AM PST

So, I watched this incredible video by Dr Tony Padilla and Brady Haran at Numberphile (https://www.youtube.com/watch?v=1GCf29FPM4k)

I can understand that if our universe was not continually expanding then it would eventually return to a state similar to what it is today, but in an accelerating expansion of the universe, won't all particles eventually be moving away from each other at apparently superluminal speeds? Doesn't this make poincarre recurrence impossible eventually?

Also, I know there are theories that quantum tunneling may generate a new big bang in the far future. Is this a well accepted theory?

submitted by /u/muckduck90
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Is there a temperature gradient on Mercury?

Posted: 27 Jan 2017 08:16 PM PST

The hot side of Mercury is 800 degrees F, and the cold side is -290F. Could there be a narrow band of hospitable temperatures where we could do a manned landing?

submitted by /u/sockpuppet998
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Is this an old volcano near Yuba City, CA?

Posted: 28 Jan 2017 12:17 AM PST

I provided the area of question in the below google maps link:

https://www.google.com/maps/@39.2633254,-121.7811932,76117m/data=!3m1!1e3

submitted by /u/WF835334
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Beyond color, what makes curly (wavy) hair structurally different to straight hair?

Posted: 27 Jan 2017 08:20 PM PST

Why are volcanic erruptions causing volcanic winters even though they emit CO2?

Posted: 28 Jan 2017 02:53 AM PST

Hello, student here, dealing mainly with climatology and GIS.

Recently I've had a quarrel with a client at the shop I am working at. He denied climate change so I tried to talk to him about it. I couldn't answer the question you see in the title.

Now that I think about it I am guessing that volcanoes emit volcanic ash, sulphur dioxide and other gasses AND CO2. So the CO2 gets into the atmosphere and it does contribute to warming, but the ash cloud prevents the energy from reaching the earth. Is it correct or am I confusing something here?

Also, another question of his wnich confused me was about the CO2 effect on warming. He said that the if the CO2 blocks radiation, then it should also block incoming radiation from sun. So it would block some of incoming radiation, and some of the earth's radiation and it should even out. I know that's not the case, but my courses don't teach ANY physics, even those dealing with climatology and climate change, so my understanding of these issues is very poor considering I am a student related to the subject. But I want to learn :( I did try to get a grasp of some basic university level physics on my own (tho failed miserably at that), so I would love you to provide a reasonably detailed explaination. I'd like to know what happens, how and why. I would gladly be also directed to any articles that deal with this issue.

In advance, thanks for help :)

submitted by /u/no_idea_help
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Are the protons and neutrons of a given element always packed in the same configuration?

Posted: 27 Jan 2017 05:57 PM PST

Take a Carbon-12 atom, for instance. It has 6 protons and 6 neutrons which are, presumably, held together in some configuration by the nuclear force. I imagine them being stacked together like the bouncy balls in the big cage in the toy section at the super center.

Is the stacked configuration always the same for every atom of C12, can it vary from one to the next, do we not have the technology to discern, or does it simply not make sense to think of nucleons as physically round objects nestled together like bouncy balls?

submitted by /u/mb3581
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What is the relationship between blood sugar and appetite, if any?

Posted: 27 Jan 2017 04:48 PM PST

So far I've found this, but the sample size is tiny and very specific (eight males ages 19-40) for such a broad topic, and their definition of appetite seemed rather ill-defined ("visual analog scale"? couldn't find a supplemental doc or anything that clarified further).

submitted by /u/Nimzowizard
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How are lightsails propelled if photons are traditionally said to have zero mass?

Posted: 27 Jan 2017 07:21 AM PST

In a vacuum, how does light propel a lightsail if it has zero mass? Does F = ma in this case?

submitted by /u/Wowliam
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Friday, January 27, 2017

Is it in any way possible to reverse a black hole?

Is it in any way possible to reverse a black hole?


Is it in any way possible to reverse a black hole?

Posted: 26 Jan 2017 10:04 AM PST

Would it be possible to remove mass from a black hole, making the gravititional pull too weak to "maintain" a singulariry? What would happen?

submitted by /u/Blackbabygsus
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How do I use a fair 6-sided die to generate a random number from 1 to 100, with each outcome occurring with the same probability?

Posted: 26 Jan 2017 12:08 PM PST

Does reflection actually happen only at the surface of a material or is there some penetration depth from which light can still scatter back?

Posted: 26 Jan 2017 01:56 PM PST

Hi,

say an air/silicon interface is irradiated with a laser. Some light is transmitted, some is reflected. Is the reflection only happening from the first row of atoms? Or is there some penetration depth from which the light can still find its way back? And if the latter is the case, how big is it? And does it still preserve the same angle as the light that is scattered back from the first row of atoms? What's going on exactly? (PhD student asking)

Thanks!

submitted by /u/nonicknamefornic
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Are the insect specimen's trapped inside amber hard or soft?

Posted: 26 Jan 2017 05:26 AM PST

I'm just wondering if the items trapped in amber get mineralized too.

submitted by /u/x_BryGuy_x
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Differentiating Magnetic Potential to get Magnetic Field?

Posted: 27 Jan 2017 04:09 AM PST

Hi all!

I am trying to find the magnetic field of the earth. I found a doc with the link below, and am reffering to the last slide on page 3.

http://rallen.berkeley.edu/eps122/lectures/L05.pdf

First off, I am confused with what magnetic potential is. I am also confused on the difference between H and B with regards to magnetic forces and flux.

Could you help me explain how differentiating the magnetic potential yields a magnetic field. Ie the conceptual understanding behind it.

THANKS!

submitted by /u/Jordanoer
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How much progress has been made in identifying the "missing" carbon sink in the last few years?

Posted: 26 Jan 2017 10:48 AM PST

I remember from an undergraduate ecology course I took in 2012 that there is an apparent deficit between projected and measured CO₂ levels in the atmosphere and oceans.

As I understand it, these projections were based on known and predicted amounts of CO₂ emissions from both anthropogenic and nonanthropogenic means as well as projected and measured rates of sequestration into terrestrial and oceanic carbon sinks, but if I recall correctly the difference between projected and measured values was massive and getting larger by the year (without any adjustment to the models).

I mean, I assume it's not just one thing. Speculating as a grad student in biochemistry (and probably over-simplifying), I wonder if it's not a Le Chatelier-like effect shifting the rate of biotic and abiotic sequestration reactions as the concentration of free CO₂/HCO₃⁻ goes up (or, alternately, an allosteric mechanism), but I assume people who specialize in that field have made efforts to account for that already.

I also remember that the Duke Forest experiment showed higher rates of carbon sequestration in a high CO₂ environment but that the soil may have been approaching limiting nitrogen conditions before the experiment was terminated.

I shouldn't need to say this, but on the off-chance this makes it to /r/all, I'm not a climate change denier. I'm just interested in how far a field outside my expertise has come in improving its models, projections and measurements (and no, this isn't homework).

submitted by /u/Ignaddio
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Little Boy v Fat Man: why were different cores used?

Posted: 26 Jan 2017 02:36 PM PST

LB was a uranium bomb and FM was a plutonium bomb. Why wasn't the same design used for both drops?

submitted by /u/thesickcardy
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How do you find the radius of an atomic nucleus?

Posted: 26 Jan 2017 11:30 PM PST

Why the does relative stiffnesses of the members of a frame affect the shape of the moment diagrams?

Posted: 26 Jan 2017 08:19 PM PST

Or, why does relative stiffness affect the moments in statically indeterminate structures but not statically determinant ones?

submitted by /u/baldemy
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How do Scientists know how fossils are related?

Posted: 26 Jan 2017 03:01 PM PST

Hello, Ok so I go to a Christian school (i'm not here to debate God). I am an Evolutionary Creationist, and my friend is a young earth creationist. He told me scientists don't know even if the fossils are related (I showed him a picture of the evolution of a whale). So besides the looks of the fossils, how else do they know if they are related?

https://evolvingplanet.files.wordpress.com/2014/05/whaleevolution-kmonoyios.gif

submitted by /u/DarkX126
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How can ions with a negative charge of 2 or more exist?

Posted: 27 Jan 2017 06:27 AM PST

I would assume that any given electron would just get repelled from the nucleus/molecule, even into a vacuum of space as a free electron. What makes the electron overcome the repulsive electro magnetic force, and allow such ions to be stable for longer than an instant?

submitted by /u/empire314
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Why don't dimensionless elementary particles emit Hawking radiation?

Posted: 27 Jan 2017 04:51 AM PST

They do have a Schwarzschild radius larger than the Planck length, and their size is technically under that radius.

submitted by /u/Nergaal
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What lasting implications could Trump's boarder wall have on the ecosystems on the US/Mexico boarder?

Posted: 26 Jan 2017 02:44 PM PST

Relationship between two properties of energy?

Posted: 27 Jan 2017 03:39 AM PST

So energy is the conserved quantity you get from continuous time-translation symmetry. Minimizing it is also the condition for a state being stable. Is there some relationship between these, or is it purely a coincidence that they happen to be the same quantity?

submitted by /u/redalephnull
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Can charge be represented in terms of mass, length, and/or time?

Posted: 26 Jan 2017 05:36 PM PST

My professor said all quantities/measurements can be expressed in units of mass, length, and/or time. In SI units, then everything can be denoted by a particular combination of kilograms, metres, and seconds. But I am wondering how one can express charge (e.g. 1 Coulomb) in terms of these 3 "fundamental" units. As far as I can tell based on basic dimensional analysis, it is not possible. The only other trivial conversion is to say 1 C = 1 A x 1 s, but this does not exactly back up my professor's claim. Thus I was wondering if perhaps I misinterpreted my professor or if charge can really be expressed in the above 3 units.

submitted by /u/CallMeDoc24
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In 2011 Michio Kaku's Physics of the Future talked about Laser Isotope Separation for enriched uranium and the lower bar to nuclear weapons this afforded to developing nations. Is it any closer to fruition half a decade later?

Posted: 26 Jan 2017 04:03 PM PST

Why is there no electric field within a conductor?

Posted: 26 Jan 2017 11:55 AM PST

Is there any correlation between how quickly eyesight deteriorates as humans age and how soon they die?

Posted: 26 Jan 2017 05:21 AM PST

Presbyopia (farsightedness due to loss of elasticity of the lens of the eye) is, from what I know, unavoidable as humans age. Is there any data that shows a correlation between how quickly presbyopia sets in and at what age you die?

submitted by /u/mikehipp
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When Siri transmits speech from a phone to a data center for speech recognition, is that speech encoded the same as a mobile phone call, or is it encoded in higher fidelity?

Posted: 26 Jan 2017 11:39 AM PST

Also Google Speech Recognition API, Alexa, etc.

submitted by /u/xaplexus
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What if there was more anti matter than matter after the Big Bang? Would we be living in a similar world made of anti matter? Or would there be nothing

Posted: 26 Jan 2017 10:07 AM PST

If you pour equal amounts of hot and cold water in a container, would the resulting mixture be the exact median of the two temperatures?

Posted: 26 Jan 2017 06:14 AM PST

Or would one overpower the other? And can someone explain the reasoning behind it?

submitted by /u/Dave_Childs
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Can an autopsy of a fetus differentiate between a medically induced abortion and a miscarriage?

Posted: 26 Jan 2017 09:06 PM PST

Having done some research on medically induced abortions, I discovered the that most common first trimester abortions are performed with the assistance of: Mifepristone and Misoprostol. However what I was unable to determine, or see any papers published on, is a first trimester abortion medically differentiable from a miscarriage.

I found this on the half life of Mifepristone: elimination of mifepristone is slow at first (50% eliminated between 12 and 72 hours) and then becomes more rapid with a terminal elimination half-life of 18 hours." Source here

I assume this means that blood work or something else would be able to detect the presence of the abortion medication in the mother, if blood work is taken within 72ish hours?

This question was inspired by a facebook conversation in which there was a claim made that this was possible.

submitted by /u/ImpactStrafe
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Thursday, January 26, 2017

Why does it take a million years for a photon moving at the speed of light to reach the sun's surface from its core?

Why does it take a million years for a photon moving at the speed of light to reach the sun's surface from its core?


Why does it take a million years for a photon moving at the speed of light to reach the sun's surface from its core?

Posted: 25 Jan 2017 05:00 PM PST

Bonus question...how much of the light reaching earth is million year old light vs. Light that was created close to the surface and is more like 5 minutes old?

submitted by /u/podank99
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What makes nuclear fusion as an energy source difficult to produce?

Posted: 25 Jan 2017 04:51 PM PST

I've read a lot about it and I'm studying mechanical engineering, so I understand the concept generally. But I'm curious/having trouble understanding the constraints on our ability to produce this kind of power.

submitted by /u/AHighFifth
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[astronomy] If the universe expanded at the same rate during the Big Bang why are there areas of high mass density( galaxies) and areas of low mass densities?

Posted: 26 Jan 2017 04:05 AM PST

How does the process of turning protons + electrons into neutrons happen?

Posted: 26 Jan 2017 05:57 AM PST

I'm in first year of high school physics and am currently doing a poster on the life cycle of stars. I was reading a bit in-depth about how the pressures inside neutron stars are so immense that the electrons are "pushed" into the protons, thus creating neutrons. What I don't understand is how this happens? As far as I know a proton consists of 2 up quarks and 1 down quark, and a neutron consists of 1 up quark and 2 down quarks. Wouldn't this proton+electron interaction mean that the proton would need to transform one of it's up quarks into a down quark? How can something like this just happen?

Also, wouldn't you need more than just a proton + electron to make a neutron? When a lone neutron undergoes beta decay it becomes a proton but also releases an electron AND an electron antineutrino. If that is the product of beta decay, why do you not need an antineutrino to turn protons and electrons into neutrons.

Sorry if this set of questions is not clear I tried to make it as understandable as possible!

*EDIT: Fixed one spelling mistake

submitted by /u/TrioXideCS
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If two video projectors play a movie in adjacent walls and their image beams cross each other, would there be any measurable degradation to the quality of the images?

Posted: 25 Jan 2017 12:59 PM PST

Can a black hole lose enough mass to be visible?

Posted: 26 Jan 2017 12:54 AM PST

Considering the effects of Hawking radiation, it is known that black holes slowly lose mass as they take in negative energy from nearby virtual particles and it is possible that they will eventually evaporate completely given enough time.

Would it be possible, at least in principle, for a black hole to lose enough mass that it could no longer sustain an event horizon?

Or does it happen that they are simply too dense? Would it depend on other factors, such as whether or not there is a true singularity at the centre, or an ultra dense arrangement of matter contained in a finite volume of space?

How does our current understanding of physics explain this?

I'm very interested in all your answers and please correct me if my understanding abut any of the above is wrong / incomplete. Thank you.

submitted by /u/Afrotom
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How are we able see the laser in darkness if all the photons are moving in one direction?

Posted: 25 Jan 2017 09:51 PM PST

Obviously in the above scenario laser is pointed in direction other than towards our face...

submitted by /u/troninron
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Does Arrow's impossibility theorem make discussion about the recent elections popular vote a waste of time?

Posted: 25 Jan 2017 10:06 PM PST

I hope it is even possible to ask a question like this here given the political nature of it.

I always thought (perhaps mistakenly) that due to Arrow's impossibility theorem, because we cannot satisfy all the fairness criterion that the majority of these arguments about the popular vote or the electorial college are largely a waste of time because whether we used that system or not, there would still be a hole (from a game theoretic perspective?).

Having said that, I have never read any commentary regarding the US election in my adult life that has ever made mention of this result.

Am I misunderstanding the theorem? Does it not apply in this circumstance?

submitted by /u/jt_lau
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What/how quantum mechanically would one constitute a stable atom/element from an unstable one? I.e how does one determine that neutrons, protons and electrons are stable?

Posted: 25 Jan 2017 08:44 PM PST

Why does small-angle approximation work the way it does in Physics?

Posted: 26 Jan 2017 05:18 AM PST

Why are there no high refractive index materials in the visible region?

Posted: 26 Jan 2017 04:11 AM PST

It seems like the range of refractive indices in the visible region is very restricted. In infrared we have lots of materials like silicon, GaAs and tellurium. And in ultraviolet most refractive indices go up drastically, although not as much as the low bandgap semiconductors. In the visible range, the highest n I know of in a useful material is 2.4 in diamond. Why is that?

submitted by /u/Wiz_Kalita
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Why is routine bloodwork not recommended for children?

Posted: 25 Jan 2017 07:18 PM PST

Why do we not perform or recommend yearly bloodwork screenings in children as we do in adults? Is it simply because being children they are less at risk?

submitted by /u/LadyAithne
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How can we tell if light has been red-shifted?

Posted: 25 Jan 2017 08:06 PM PST

What ever happened to graphene?

Posted: 25 Jan 2017 05:47 PM PST

I remember reading up about it a while ago, the amazing miracle substance. The articles I looked at couldn't shut up about how amazing this stuff is and how it will basically improve everything. I did a little more research today and learned it was invented back in 2004, is it normal for the indoctrination of new materials to take this long? I know that apparently no one really knows how to mass produce it at a reasonable cost, I'm just wondering why it seems like very little progress is being made and how much longer till we start seeing graphene show up in more and more products.

submitted by /u/Giant_Bearded_Face
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What is the fundamental difference between a space dimension and a time dimension?

Posted: 26 Jan 2017 03:23 AM PST

Referring to this SMBC comic. Why would multiple time dimensions make travelling through space easier? http://www.smbc-comics.com/comic/the-dimension-store

submitted by /u/M4rkusD
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Is there any connection between red clay soil types and gold veins?

Posted: 25 Jan 2017 08:48 PM PST

Recently on /r/AskanAmerican, a Georgian commented that there's a lot of red clay out in Georgia. I grew up in the Gold Country of California. There's a lot of red clay out here too.

America's first gold rush was in Georgia and its most famous was here in California. Is there some connection between red clay and gold veins?

submitted by /u/RsonW
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Before it became associated with the period of a 133 Caesium atom, what was the consensus as to how long a second was?

Posted: 25 Jan 2017 03:17 PM PST

Are molecular orbital theory and hybridization compatible?

Posted: 25 Jan 2017 04:59 PM PST

We learned about hybridization (sp, sp2, etc) in class and later we learned about molecular orbital theory. They seemed to give different shaped orbitals so I am a bit confused on if they are competing theories, if they are different sides of the same coin, or if I am misunderstanding. I would really appreciate some help, thank you reddit.

submitted by /u/thebakedpenguin
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Are there stars that are powered by fission?

Posted: 25 Jan 2017 10:41 PM PST

I know that stars are fueled by nuclear fussion. But are there any stars that are powered by fission. And if not is it even possible by our current understanding of physics?

submitted by /u/slayeropolis
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When I shower in the winter, a fan pulls the warm air out of the room while a vent pushes warm air into the room. Does this make the room warmer by venting heat in or colder because of Bernoulli's principle?

Posted: 25 Jan 2017 06:53 PM PST