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Saturday, April 14, 2018

How common is lightning on other planets?

How common is lightning on other planets?


How common is lightning on other planets?

Posted: 14 Apr 2018 02:01 AM PDT

How common is it to find lighting storms on other planets? And how are they different from the ones on Earth?

submitted by /u/Tonroz
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If we weren't counting, would there be a way to tell how old we were?

Posted: 13 Apr 2018 05:16 PM PDT

How do lakes maintain any depth overtime?

Posted: 13 Apr 2018 04:11 PM PDT

It seems like the amount of organic matter being added to a lake would always outstrip its ability to shift sediment out through any draining creeks, even more so for those that don't have major out flows.

submitted by /u/Solmeaus
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The closer you get to a massive body, the faster you need to go to orbit. For earth, air resistance limits closeness you can achieve orbit at, but is there a theoretical limit for how close your orbit can be, on bodies without an atmosphere?

Posted: 13 Apr 2018 04:15 PM PDT

For example, on the moon, could you orbit at 500 ft, if you were going fast enough? 50 ft? 5?

submitted by /u/non-troll_account
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Do plants near highways or busy roads have different cell structure, due to emissions, compared to plants in a forest?

Posted: 13 Apr 2018 02:26 PM PDT

Do adopted children take on personality traits in favour of their biological or adopted parents?

Posted: 13 Apr 2018 04:07 PM PDT

What happens when a turtle ends up upside down in the wild? Does it just lay upside down till it dies?

Posted: 13 Apr 2018 05:39 PM PDT

How are heat sink compounds both graded, and selected for use? Whose prime area of expertise is this?

Posted: 13 Apr 2018 06:38 PM PDT

On the whole, when an end user buys heat sink compound there's no great need for in-depth decisions. A 1.5g tube for $5-10 will probably be fine. But my Mac, I discovered, has at least two quite distinct grades of compound in use. There's a higher-performance paste between the GPU and its heat sink, and a much thicker paste plastered on to all the VRAM chips on the graphics card. It looks like tile grout, to be honest, and it has to be plastered on about 3mm deep in order to give thermal contact between the very low-profile VRAM chips and the graphics card heat sink they lie under.

This got me wondering. How do engineers decide what grades of heat sink compound to use? How much does it matter? How many different grades are there in common use? Is selecting the right compound taught in Electrical Engineering these days, and if not, which discipline does consider it? My £5 tube specified its viscosity, thermal conductivity, operating temperature range and maybe 1-2 other things as well I don't remember. But I didn't understand the significance of any of those numbers, so all I could do was assume the numbers were reasonable for my use case and glop it on. If, as an engineer, you calculate that you do need some specialised compound, where can you obtain it from? What use cases require special formulas??

I did know heat sink selection could be a serious business, but I hadn't appreciated that choosing the right heat sink compound could be equally finicky.

submitted by /u/Simons_Mith
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How do Lasers burn objects? Do the stream of photons actually impart energy in the form of heat upon absorption, or does the act of hitting a surface create some sort of friction-based heat?

Posted: 13 Apr 2018 04:21 PM PDT

I'd imagine it's not friction-based or else glass would heat up as light passed through it, plus, someone once told me that light cannot generate friction because it lacks the mass, although I have no idea whether that's true or not. It doesn't sound right, but I'm far from being an expert.

Also, I know that dark surfaces are meant to get hotter in the sun than lighter surfaces because they reflect less light and absorb more - I'm guessing this would be the same for a laser beam, the absorption of light generating the heat?

submitted by /u/gjs628
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Are Astronauts on the ISS required to speak multiple languages?

Posted: 13 Apr 2018 03:41 PM PDT

For example, are the Cosmonauts required to speak English? And the Astronauts required to speak Russian?

Edit: not really astronomy but I feel as though it's the most relevant flair

submitted by /u/sammiali04
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Do starchier plants deteriorate slower than plants with higher sugar content?

Posted: 13 Apr 2018 04:25 PM PDT

Why does administering IV Dexamethasone too quickly cause a burning/itching sensation in the recipient's groin?

Posted: 13 Apr 2018 09:14 PM PDT

We call it "ants in the pants" or "ring of fire." Pushing the med slowly helps but some patients are ultra sensitive & some days unfortunately I can't spend that much time on it. This is a question that obviously comes up from patients on an almost daily basis. I'd be remiss not to attempt to find out why.

submitted by /u/mid_1990s_death_doom
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What affect does pollution have on flight?

Posted: 13 Apr 2018 08:26 PM PDT

Is there a difference between flying through clean air vs. flying through smog/pollution?

submitted by /u/inertiaWORKS
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The Large Hadron Collider is 27km long in order to stably accelerate particles, but is there any hope of miniaturization in the future?

Posted: 13 Apr 2018 11:37 AM PDT

Can the mass of a particle change?

Posted: 13 Apr 2018 09:20 AM PDT

Since almost all of the mass of a particle is from the binding energy it holds, Is it possible to reduce the amount of binding energy there is in the particle by making it cooler or hotter or other weird scenarios which could effectively change the binding energy and hence the mass?

submitted by /u/JackTalle
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Are there any "flighted" birds that opt not to fly?

Posted: 13 Apr 2018 12:58 PM PDT

I guess my questions is that we all know there are bird species that cannot fly, my guess is because they were able to survive without flying. Are there any species of birds that are in that transitional phase of being able to fly but able to thrive without flying very much or not at all?

submitted by /u/prick-in-the-wall
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Does Halley's comet get smaller after each orbit?

Posted: 13 Apr 2018 09:00 AM PDT

If the tail of the comet is all the melting ice and dirt then should it be getting smaller. Or does it gain more ice and dirt as it flies back into deep space?

Edit: I misspelled tail

submitted by /u/DrPotatoEsquire
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I have two pieces of wood. One is burnt by fire. The other is burnt by a lightning strike. Is there anyway to distinguish between the two?

Posted: 13 Apr 2018 05:14 PM PDT

Will Earthquakes and Volcanos Eventually Stop? If so, when?

Posted: 13 Apr 2018 08:20 AM PDT

As I understand it, Earth was once entirely molten, and then began cooling and the crust formed, and that's where we all live. We have earthquakes because forces under the crust push the pieces around, and we have volcanos because the crust isn't very thick in some places and/or that's where two crust pieces meet and the molten stuff underneath pushes out.

If cooling is still going on, shouldn't the crust still be getting thicker, and at some point won't the crust be so thick these things stop happening? Right now, the crust isn't even 100km thick. If it was 150km, or 200km, or 500km thick, would that be enough to stop tectonic movement, and thus bring an end to earthquakes, and also be too thick for volcanos to push out?

How thick would the crust have to be for earthquakes and volcanos to stop? How long will it take for the crust to get that thick?

submitted by /u/MyActualRealName
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Friday, April 13, 2018

If extra wings seen on biplanes add more lift and maneuverability, why don’t we add them to modern planes or jets and have them built into the airframe like we do today?

If extra wings seen on biplanes add more lift and maneuverability, why don’t we add them to modern planes or jets and have them built into the airframe like we do today?


If extra wings seen on biplanes add more lift and maneuverability, why don’t we add them to modern planes or jets and have them built into the airframe like we do today?

Posted: 13 Apr 2018 05:05 AM PDT

Does the moon or other planets have magnetic poles?

Posted: 12 Apr 2018 10:51 PM PDT

Would we be able to use a compass there like we do here?

submitted by /u/frickfrackcute
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Why are cooling towers shaped the way they are?

Posted: 13 Apr 2018 04:28 AM PDT

Power plants or large factorys all have the same shape of their cooling tower. The radius is smaller in the middle and widing up on top again. Whats the reason we dont use the same radius everywhere or it only gets smaller higher up.

submitted by /u/IntenSIEF
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Does body language have 'dialects' as such?

Posted: 13 Apr 2018 05:40 AM PDT

What exactly happens when Polyurethane foam is formed?

Posted: 13 Apr 2018 03:20 AM PDT

I am currently doing my mechanical engineering dissertation on making structures using polyurethane foam, I have no background in chemistry and reading through many papers on polyurethane I find them hard to follow sometimes. I have searched through many papers to try and find what is going on but I cannot. Basically I have seen studies whereby the PU foam is formed within a vacuum, however in my experiments I have tried to form PU foam within a bag and it does not expand anything like it does when open to the air. Can anyone explain what is going on and why air is needed? Or am I missing something ? I am using 2 part pour-able foam.

TL:DR Polyurethane 2 part foam is not expanding properly when not exposed to air, why?

submitted by /u/teegfit1
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Do birds have tastebuds?

Posted: 13 Apr 2018 05:32 AM PDT

What draws them to French fries, potato chips, and other "snacky" foods?

submitted by /u/meganzin
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Why doesnt AIDS burn itself out?

Posted: 13 Apr 2018 06:04 AM PDT

Shouldnt there be a point where AIDS kill all of the lymphocytes that are its host, therefore not being able to reproduce anymore and dying. I.e burning itself out.

submitted by /u/nanaro10
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Can current models accurately predict the temperature of super nova stars just before they explode and create a black hole?

Posted: 12 Apr 2018 10:37 PM PDT

can the temperature be predicted as a star implodes, is there evidence to support how accurate the predictions of those temperatures are?

submitted by /u/CajunKush
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If my weather app breaks down the probability of precipitation by hour, how do I determine the probability for the day?

Posted: 13 Apr 2018 05:38 AM PDT

Right now it says 40% chance for the next two hours, 50% for the next hour, 56% for the next two hours, and then 30% for the rest of the evening.

If each of these is independent, does that mean the probability for the whole day is very high? Or is the whole day probably still around the 50% range?

submitted by /u/pm_me_ur_demotape
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Why can't processors guarantee calculation of a known problem in constant length of time?

Posted: 13 Apr 2018 04:41 AM PDT

All commercial airplanes basically have the exact same design; is that by necessity or happenstance? Did it really have to be that one way?

Posted: 12 Apr 2018 10:25 PM PDT

How do animals without parental figures know what species to mate with?

Posted: 12 Apr 2018 01:19 PM PDT

Differing forces in different reference frames?

Posted: 13 Apr 2018 05:06 AM PDT

Posted the question in the r/Physics thread but haven't gotten any answers so figured I might try my luck here.

A question that has been confusing me for a while now:- Firstly, we consider the day-to-day frame of reference that we normally think about. We are pulled down by a gravitational force mg downwards, and pushed up by the normal force of same magnitude provided by the ground - hence we stay stationary on the ground with no acceleration. However, if we look at the entire Earth as a reference frame, the Earth is rotating on its axis and we are rotating on it with the same angular velocity. Then clearly we cannot have the normal force N=mg, since in that case we would have no net acceleration and will not rotate in a circle around the Earth's axis.

So this is the part where I get confused about what forces are in play here. I think the normal force by the Earth in that reference frame must not be opposite to the gravitational force, but rather their vector sum should point towards the Earth's rotational axis to provide us with the centripetal acceleration. However in that case, why does the same(?) normal force appear to be acting in different directions in different reference frames? I also might be wrong in my analyses of forces present and there is another (pseudo?)force that can help explain this problem.

submitted by /u/IFTClerk
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Why does the Pauli Exclusion Principle apply to fermions but not to bosons?

Posted: 12 Apr 2018 12:53 PM PDT

Can a x86_64 CPU be designed to run code meant for ARM_64?

Posted: 13 Apr 2018 12:43 AM PDT

Unless I got something wrong a x86_64 should be able to handle all the instructions that an ARM_64 can, just at reduced speeds.
Would this even worth doing?
Or would it be just as fast to emulate an ARM_64 CPU?

submitted by /u/Starf4rged
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Could you make a Silicon version of Graphene?

Posted: 12 Apr 2018 01:43 PM PDT

Would it be possible to have a silicon (or other element in that group/column) equivalent of graphene where the atoms are arranged in the same manner? I imagine this substance would have similar properties to the carbon version.

submitted by /u/TheWierderOne
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Why do some plants have colorful (not green) leaves in the spring and summer and not just in the fall?

Posted: 12 Apr 2018 11:33 AM PDT

Something like a japanese maple comes to mind

submitted by /u/Forestpotato
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If there is an absolute cold, is there an absolute hot?

Posted: 12 Apr 2018 04:43 PM PDT

Is development of muscle memory partially performed outside the brain?

Posted: 12 Apr 2018 09:01 AM PDT

I'm aware that many changes occur in the brain when developing muscle memory, but I do not know to what degree the part of the somatic nervous system outside the brain changes and whether or not those changes are largely significant to performing a particular motor function. If you were to learn to play the guitar but, after doing so, only retained the neural development done directly in your brain, would you still have the capacity to play? I understand this is a hypothetical question to a degree, but the information the answer provides is relevant to the more concrete question underneath.

submitted by /u/ZaxasT
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Thursday, April 12, 2018

Why do certain flavours go well together? E.g. chicken/coleslaw, tomato/mozarella, spinach/garlic, walnuts/honey, tuna/mayonaise?

Why do certain flavours go well together? E.g. chicken/coleslaw, tomato/mozarella, spinach/garlic, walnuts/honey, tuna/mayonaise?


Why do certain flavours go well together? E.g. chicken/coleslaw, tomato/mozarella, spinach/garlic, walnuts/honey, tuna/mayonaise?

Posted: 12 Apr 2018 03:01 AM PDT

Why does my hearing go muffled when I get a headrush from standing up?

Posted: 11 Apr 2018 11:49 AM PDT

Giraffes only sleep a cumulative 30 minutes per day. They take brief, minute-long naps throughout the day, all while standing up. How are they able to function without large amounts of rest?

Posted: 11 Apr 2018 01:24 PM PDT

In quantum tunneling, if an electron has energy 2eV, why can it escape if 5eV is the energy to escape? Where does this energy come from?

Posted: 12 Apr 2018 05:17 AM PDT

If the Milky Way is moving through space, is it orbiting something bigger?

Posted: 11 Apr 2018 12:12 PM PDT

Why is voltage and current specified in electrical equipments?

Posted: 12 Apr 2018 04:41 AM PDT

My phone charger, for example, has an output of 1.55A at 5V. My understanding is that Voltage causes current to flow. Current is the rate of flow. So in the case of my charger, does the voltage here matter? Why is it specified? To calculate power? What if I have another charger that's 1.55A at 10V? What does that mean? Surely, my phone isn't getting charged faster because they're both 1.55 coloumbs of charge per second.

submitted by /u/KillCq
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Where does the fat go?

Posted: 11 Apr 2018 06:28 PM PDT

I recently lost 20 pounds (yay me!) and I wonder... Where did it go? Did I pee it out or did it change into something else?

submitted by /u/Mamashake
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How does mica rotate plane polarized light by 90 degrees?

Posted: 11 Apr 2018 09:06 PM PDT

I have a few pieces of iolite that allow me to demonstrate this property really effectively, but I don't have a good explanation for how the mica's crystal structure results in the rotation of light. I understand how a crystal's optical properties are determined by its symmetry and structure, and that mica is extremely anisotropic (hence its cleavage), and the pleochroism exhibited by iolite is intuitive enough to me, but the rotation caused by mica isn't quite clicking for me.

submitted by /u/ExsolutionLamellae
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What mechanism prevents hernias from healing on their own and necessitating surgery?

Posted: 11 Apr 2018 07:24 PM PDT

What happens when you use Knuth's up-arrow notation with non-natural numbers?

Posted: 11 Apr 2018 04:26 PM PDT

Suppose you take Knuth's up-arrow notation. Using it on integers is easy: 3 ^ 3 = 33 = 27, 3 ^ ^ 3 = 333 , etc. But what happens if you place a fraction as the latter number? 3 ^ (1/3) is obviously the cubic root of 3, but what about 3 ^ ^ (1/3)? What if we place a negative number instead? Or a complex number?

submitted by /u/Apophyx
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Ask Anything Wednesday - Engineering, Mathematics, Computer Science

Posted: 11 Apr 2018 08:14 AM PDT

Welcome to our weekly feature, Ask Anything Wednesday - this week we are focusing on Engineering, Mathematics, Computer Science

Do you have a question within these topics you weren't sure was worth submitting? Is something a bit too speculative for a typical /r/AskScience post? No question is too big or small for AAW. In this thread you can ask any science-related question! Things like: "What would happen if...", "How will the future...", "If all the rules for 'X' were different...", "Why does my...".

Asking Questions:

Please post your question as a top-level response to this, and our team of panellists will be here to answer and discuss your questions.

The other topic areas will appear in future Ask Anything Wednesdays, so if you have other questions not covered by this weeks theme please either hold on to it until those topics come around, or go and post over in our sister subreddit /r/AskScienceDiscussion , where every day is Ask Anything Wednesday! Off-theme questions in this post will be removed to try and keep the thread a manageable size for both our readers and panellists.

Answering Questions:

Please only answer a posted question if you are an expert in the field. The full guidelines for posting responses in AskScience can be found here. In short, this is a moderated subreddit, and responses which do not meet our quality guidelines will be removed. Remember, peer reviewed sources are always appreciated, and anecdotes are absolutely not appropriate. In general if your answer begins with 'I think', or 'I've heard', then it's not suitable for /r/AskScience.

If you would like to become a member of the AskScience panel, please refer to the information provided here.

Past AskAnythingWednesday posts can be found here.

Ask away!

submitted by /u/AutoModerator
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How do Electromagnets Work with Conservation of Momentum?

Posted: 11 Apr 2018 07:06 PM PDT

I'm a grad-level physics major, but a couple of days ago I got asked a question that I still haven't been able to satisfy myself that I fully understand.

Suppose you have two solenoids, A and B, separated by some distance.
A is connected, generating a static magnetic field. B is not, and is a broken circuit (i.e. cannot sustain current at all).

I connect B, so that it is pushed outwards by A's field, and then immediately disconnect A so that it has no dipole moment. Because the field from B takes time to propagate, coil A will have zero dipole moment by the time the field "arrives", and so no reaction force will be generated. One object has been pushed, while the other has not, seemingly generating thrust from nowhere.

Time-varying fields aren't my strongest point, so I strongly suspect that what I'm missing is somehwere in the turning of the coils "on" and "off", i.e. that the changing fields in this window generates a non-zero Poynting vector, but this doesn't seem to grok with the symmetry of the problem.

submitted by /u/Sand_Fall
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Is the element Mercury named after the planet, or is the planet named after the element? Or are they related at all?

Posted: 11 Apr 2018 06:36 PM PDT

What reasons necessitate the imidazole ring in the base pairing of RNA/DNA?

Posted: 11 Apr 2018 04:38 PM PDT

Specifying: This is not asking 'why is there an imidazole ring in a purine'.

Rephrasing: What reasons prevent the phosphate backbone DNA/RNA from using ONLY pyrimidines in their base pairs?

Here are some things I could speculate possibly being the case:

Is there not enough variety in naturally occurring pyrimidines to support enough base pairs?

Is it because the hydrogen bonds between pyrimidines for whatever reason are either stronger or weaker than ideal for the various processes that depend on hydrogen bonds?

Is it that a pyrimidine base pair would, because of being of shorter length, end up twisting the backbone more than it wants to be twisted, and/or stacking too much closer to the other base pairs? (for processes that depend on the power necessary to untwist the helix, and overcome the stacking energy)

Is it that this configuration would not support the major and minor groove that becomes necessary in other processes?

I know I have yet to read further in depth, specifically, on the topics of pi stacking and the ultimate function or necessity of the major and minor grove.

Thank you

submitted by /u/RNA-curious
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CRISPR Cas9 - How does the Cell decide which repair pathway to proceed with?

Posted: 11 Apr 2018 03:02 PM PDT

I understand that Cas9 is an endonuclease that makes a nick in the DNA, but then how does the cell decide whether to proceed by non-homologous end-joining or homologous recombination?

submitted by /u/MaldororHollow
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Can strong wind influence the path (or the speed) of sound and light?

Posted: 11 Apr 2018 02:52 PM PDT

not sure if its a legit question or just dumb. but speed and sound travel through matter at a certain speed (i think). if that matter happens to be air, and if that air happens to be a strong wind, would this mean that it does get influenced?

submitted by /u/jokasi58
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What’s in the direct center of a black hole? When light and other various things get sucked into the black hole what happens to them? Are they crushed? What happens when something goes into a black hole?

Posted: 11 Apr 2018 11:56 AM PDT