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Wednesday, June 14, 2017

Has anti-hydrogen formed bonds to form anti H2? If not what circumstances would you need?

Has anti-hydrogen formed bonds to form anti H2? If not what circumstances would you need?


Has anti-hydrogen formed bonds to form anti H2? If not what circumstances would you need?

Posted: 13 Jun 2017 02:24 PM PDT

I am assuming that a bunch of trapped anti-hydrogen atoms will like to form bonds with each-other as regular hydrogen does (you don't really have a way to have atomic hydrogen in the gas phase)

submitted by /u/kkllee
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Why do most objects in the night sky (stars and planets) look to be the same size relative to our naked eyes?

Posted: 14 Jun 2017 06:19 AM PDT

In general, by how much percent can solar and wind take over an energy grid, before we need batteries or alternatives that can respond to time-varying energy demands?

Posted: 13 Jun 2017 05:21 PM PDT

My understanding is that, because our energy demands are not constant, a 100% solar and wind energy grid would be impossible or impractical without advanced storage technologies that are currently not economically viable. But where is the "cross-over" point; when does it become impractical to continue to rely on these instead of scalable resources like nuclear, hydro, natural gas, and coal? Or is my understanding not entirely correct?

submitted by /u/schnadamschnandler
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In a documentary about the Manhattan Project I recently viewed (I don't recall the name of it, I apologize), some of the scientists expressed their concern about the "atmosphere exploding" and destroying the Earth during the Trinity test. What scientific basis did they have for this speculation?

Posted: 13 Jun 2017 10:06 AM PDT

Do electric cars use electrical energy from the battery more efficiently than gasoline/diesel cars use heat energy from their fuel?

Posted: 13 Jun 2017 11:22 AM PDT

Simple question: In terms of total Joules of energy transmitted to the crankshaft (...or whatever electric cars connect to the drivetrain), which is the most efficient, strictly speaking?

submitted by /u/schnadamschnandler
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How long could a snorkel be (or how deep into the ocean could it go) before you could no longer suck air into it from the bottom?

Posted: 13 Jun 2017 07:11 PM PDT

Imagine you had an X foot long snorkel, and you tried to breathe from it from X - 0.5 feet underwater. How deep could it go before your lungs couldn't pull adequate air in?

submitted by /u/pupton_sinclair
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How is a large body of mass trapped inside of another's gravity well as a moon? Doesn't it need to slow down in order to circularise its orbit?

Posted: 13 Jun 2017 12:37 PM PDT

Forgive my crude understanding of orbital mechanics but it was my understanding that if an object is caught in a gravity well with no means to slow down then it will either impact or be flung off in another direction. A recent article about Jupiter having two new moons caught my attention and that they were captured. Is it not that the object caught up to the planet but that the planet caught up to the object and thus it never had escape velocity to begin with?

submitted by /u/OverDoseTheComatosed
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Is there a maximum​ amount of light that a black surface can absorb?

Posted: 13 Jun 2017 11:50 PM PDT

Can there be enough incident photons that saturate the surface? If so, what happens to the extra photons? What would we see? Would the black object get damaged?

submitted by /u/JarJarAwakens
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How much of a barrier is the atmosphere for a spacecraft launched at orbital speeds?

Posted: 14 Jun 2017 02:24 AM PDT

I'm often fascinated by alternatives to rocket launches, and how viable they would be - space elevator, launch loop, etc. However, for some of these ideas, a big obstacle is the earth atmosphere - for example, using a Linear induction motor in a vacuum tube to accelerate up to orbital speed would leave you with a rocket at low altitude, which then still has to punch through the atmosphere before arriving in space.

Now when a spacecraft re-enters the atmosphere, it uses the atmosphere as a breaking mechanism strong enough to land safely on earth, and it already uses the upper part of the atmosphere for much of the speed reduction. This would suggest bad thingsTM would happen to a spacecraft going orbital speeds at sea level.

However, spacecraft are usually aerodynamically designed specifically to use the atmosphere for breaking, rather than trying to minimize drag and punch through the atmosphere.

So thats my question - Would a spacecraft launched with orbital speeds(in the range of 6-10 km/s) designed with minimizing aerodynamic drag be capable of escaping the atmosphere intact? Would it still have a reasonable amount of speed left?(as in, would it leave the atmosphere with 90% of its original speed, or 10% of its original speed?) And would the answer to this question change meaningfully if the spacecraft was launched from a height of 10 kilometers, to avoid the most dense atmosphere?

submitted by /u/asphias
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Would the viscosity of a liquid affect how far it shoots out of a squirt gun?

Posted: 13 Jun 2017 02:18 PM PDT

If you have a squirt gun that shoots the same every time and you shoot it at the same angle, would it go farther if it was more viscous liquid or a less viscous liquid

submitted by /u/DontRunItsOnlyHam
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What technological limitations are keeping us humans to desalinate seawater and provide every human clean water?

Posted: 13 Jun 2017 07:08 PM PDT

How could I calculate the maximum size of a water balloon before it bursts?

Posted: 14 Jun 2017 04:23 AM PDT

I've got a BSc in Physics and I'm wondering what the maximum size of a water balloon or any other liquid filled spherical object would be before it breaks under it's own weight, depending on the strength of the shell material. How do I calculate the pressure on the shell and relate it to it's mass and volume?

submitted by /u/ViceArchimedes
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Why does plasma smell the way it does?

Posted: 13 Jun 2017 05:04 PM PDT

I bought a little plasma lighter like this and I noticed it gives off a very refreshing clean smell. The best way I can explain it is that it smells like extremely fresh air.

Is there any reason for this? It is quite a characteristic smell that I have never smelled before.

submitted by /u/ekpg
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It's possible to supercool or superheat a liquid so that it instantly boils or freezes when disturbed. Is it possible to do something similar with other phase transitions, such as producing a block of ice that will instantly melt?

Posted: 13 Jun 2017 09:51 AM PDT

Do you get drunk easier in higher altitudes?

Posted: 13 Jun 2017 06:01 PM PDT

What direction will a photon travel in?

Posted: 13 Jun 2017 10:31 PM PDT

Massless particles in a vacuum must travel, C, the speed of causality (and light). Ok. However, what gets me is the direction the photon is traveling in. In order to travel at C it must have to choose a direction. We typically think of photons and light having momentum in a certain direction (for example the sun's photons coming towards earth). However, imagine a newly created photon with no momentum (in terms of direction). What direction will it decide to travel. Let's assume an idealistic case where only the photon exists in a vacuum without small influences from external forces. Surely, if there's no momentum and the particle just exists, that seems to violate the idea that all massless particles in a vacuum travel at C. My intuition tells me that a photon will always have a preferential direction due to external influences and the initial conditions from where it was created. However, most laws hold up in idealistic cases and external influences we just count as residual errors in experiments. It seems as though the reverse is true in this case. Maybe another case is to think about a photon with momentum X and an external influence causing an equal and opposite momentum contribution to the exact decimal value causing the photon to stay in one place. What will happen?

submitted by /u/Quantum__Tarantino
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Is it possible for a planet to have multiple rings of asteroids (like Saturn's one ring) at different angles from each other?

Posted: 13 Jun 2017 02:49 PM PDT

Can we generate and use magnetic fields to protect astronauts from radiation or channel radiation in specific directions?

Posted: 13 Jun 2017 09:24 PM PDT

The earth generates a magnetic field which protects us from most solar radiation, can the same effect be used to protect astronauts or to channel radiation into a safe direction?

submitted by /u/PowerPuffSoldier
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People hate to hear about nuclear waste, so why haven't we built integral fast or SCFRs to use up the uranium-238 and plutonium-239 that we do have?

Posted: 13 Jun 2017 02:19 PM PDT

Seems it would make sense. Say you can solve the nuclear "waste" crisis with technology proven to work in the past and people generally throw money at you.

submitted by /u/pleasantvalleymonday
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Is there a limit to how big speakers can be made today?

Posted: 13 Jun 2017 05:47 PM PDT

A while back there was an episode of Rick and Morty where they perform to some giant alien heads using a 'top secret' US gov't amphitheater (?) with humongous speakers. Is it possible for humans to build speakers like this today? Or would impedance limit the amount of electrical current in the coils, such that they would only be able to play up to a certain frequency of sound? The speakers I'm referring to can be seen in the following music video (at the 5s mark, as in the link): https://youtu.be/n4Xp6g-_UUw?t=5s

submitted by /u/freddo631
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Does gut bacteria affect our taste?

Posted: 13 Jun 2017 04:05 PM PDT

If we lack a certain type of bacteria in our gut does that in turn make it taste worse so we avoid ingesting it? Anecdotally, I'm allergic to peanuts and find they taste horrible...could that be because I lack the bacteria needed to consume peanuts?

submitted by /u/gretchenweinershair
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If Quantum Field Theory most accurately describes phenomena at very small scales, why are "particles" still defined and used at those scales?

Posted: 13 Jun 2017 05:00 PM PDT

I understand that in QFT, very small particles are excitations in fields (e.g. Higgs boson in the Higgs field), but why are particles defined at all, at those scales?

For example, isn't the LHC actually accelerating and colliding field excitations (protons), which results in more field excitations (Higgs boson)?

Or are partilces and fields just two different ways of describing the same phenomena by different theoretical frameworks, particle physics theory and QFT? I think this the correct answer, but then I'm wondering why "particles" are used in QFT. Are they shorthand for a quantization of its field's excitation?

submitted by /u/MrSpaceman
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Questions regarding the particle and wave duality of light?

Posted: 13 Jun 2017 10:03 PM PDT

I only understood light with the wave model in mind but want to expand my knowledge to encompass the entirety of the particle/wave duality. I did research and I came up with a few questions.

  1. How can a particle have a frequency, amplitude, or wavelength? Is it moving up and down just like a wave? Or is it the spacing in between the particles? If it is the spacing, then is how is amplitude recorded?

  2. What determines the intensity of light? I know we learned this in the context of waves but I want to know if it still applies with photons in mind and the details of how and if I should think of it differently.

  3. Are all photons the same? Are there different sizes/energies or just different quantities of the same size/energy?

  4. Is the wave model of light sufficient in explaining light in ALL contexts EXCEPT the photo-electric effect?

  5. Does a photon have a definite shape and/or mass?

I apologize if any of these questions are amateur. I merely want to understand. Any response is appreciated.

submitted by /u/Sorual
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Tuesday, June 13, 2017

We encounter static electricity all the time and it's not shocking (sorry) because we know what's going on, but what on earth did people think was happening before we understood electricity?

We encounter static electricity all the time and it's not shocking (sorry) because we know what's going on, but what on earth did people think was happening before we understood electricity?


We encounter static electricity all the time and it's not shocking (sorry) because we know what's going on, but what on earth did people think was happening before we understood electricity?

Posted: 12 Jun 2017 05:41 PM PDT

Is there an economic mechanism that prevents a few entities from acquiring all of the housing and renting it out?

Posted: 12 Jun 2017 08:50 AM PDT

It seems like it would be possible for extremely wealthy individuals and companies like Blackstone to just continually acquire housing and then leverage rent-backed securities and inelastic demand to rent that housing out indefinitely, which would create scarcity in housing that can be purchased, which would further drive up the cost of ownership and force more people to be stuck renting. Is there some economic principle that will prevent this or has prevented it before? Are we heading towards a future where nobody owns their home?

submitted by /u/codyish
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Why don't we sneeze in our sleep?

Posted: 12 Jun 2017 08:47 PM PDT

Is reinforced concrete able to function as a faraday cage? And if so does it make a building save of EMPs?

Posted: 12 Jun 2017 01:47 PM PDT

Does the steel inside reinforced concrete form a faraday cage if you build a building? If so, does it prevent electronics from being damaged from an EMP if it is inside such a building?

submitted by /u/Freakwave91
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In the event of a nuclear war (with humanity's current arsenal being used) How long would it take for the bioshpere to regenerate? (if it would at all)

Posted: 13 Jun 2017 07:10 AM PDT

I guess I should define regenerate. Let's say, pre-war levels of habitability for humans, and animals. Though knowing chernobyl, animals couldn't give a bother about radition.

submitted by /u/Doveen
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Far away galaxies recede from us at a speed proportional to their distance... but what are their speeds relative to the cosmic microwave background?

Posted: 13 Jun 2017 04:25 AM PDT

So when it comes to cosmology we (non astronomers) are always told that expansion of the universe is like a cake leavening in an oven: pieces of chocolate get their distance to each other increased even though they don't move through the dough. Or like fish swimming in a fast flowing river, so that even if they swim slowly through the water the current carries them at a higher speed.

Please take it easy because in Engineering school we're only taught SR, not GR.

My current understanding is that the Big Bang happened everywhere. Anyone on any galaxy would see him/herself as the center of the observable universe because all galaxy clusters recede from each other.

Does this all imply that their speeds relative to the CMB are low or nearly at rest? (Ours is just 630 km/s which is almost nothing at a cosmological scale)

Cosmology always blows my mind.

submitted by /u/katinla
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What does it mean to say that waves in the electric field move perpendicular to waves in the magnetic field?

Posted: 12 Jun 2017 05:50 PM PDT

The pictures in my textbook show them as two transverse waves, but that doesn't quite make sense to me. Which way is 'up' to the electric field?

submitted by /u/Ass_Dragon
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Is bonding angle between atoms in a crystal changed significantly under mechanical strain?

Posted: 12 Jun 2017 11:37 AM PDT

For example, does slightly bending a metal bar significantly change the crystal structure?

submitted by /u/dredged_chicken
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Unlocking my door made my headphones stop working?

Posted: 13 Jun 2017 07:25 AM PDT

The door to my flat has a magnetic locking system that uses a keycard to open, much like most modern hotels use.

Today, I arrived at my door whilst listening to music on my phone through pretty standard in-ear headphones. At the exact moment I unlocked the door (simultaneous with the green light on the lock indicating this), my music went completely silent. The volume on my phone was still up, but no sound was coming out.

Was this a well-timed coincidence or did some sort of reaction take place? The headphones worked absolutely fine after re-plugging.

submitted by /u/HyderintheHouse
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Is wearing Bluetooth headphones all day dangerous to our health?

Posted: 13 Jun 2017 07:02 AM PDT

My dad will not let me use wireless bluetooth headphones because he is CONVINCED they are cancer causing. Can I have help accumulating proof that he is wrong. There are a lot of websites that look very questionable and few that are known for credibility; please help. Thank you

submitted by /u/ComputerWiz77
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Is the sun's hydrogen (both deuterium and tritium) metallic and how would fission of metallic hydrogen differ from gaseous hydrogen?

Posted: 13 Jun 2017 05:20 AM PDT

How would you measure the speed of light using typical household appliances and materials?

Posted: 12 Jun 2017 02:13 PM PDT

When someone calls my cell phone, how does the telecom infrastructure "find" my phone?

Posted: 13 Jun 2017 12:56 AM PDT

I can be anywhere in the country and a lot of places around the world and I will still receive calls in a matter of seconds. The cell towers can't possibly scan every single phone in the world looking for mine. I have an area code but the number works just as well if I'm not in my hometown. So how do the computers and companies that run these things figure out where I am and where to send the phone call so quickly?

submitted by /u/Scarlette_Lee
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Artificial gravity is possible?

Posted: 12 Jun 2017 07:58 PM PDT

Is it possible, and if so how can you create artificial gravity in space like they have in the movies, if so why haven't they?

submitted by /u/adamfez
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Time dilation while accelerating?

Posted: 13 Jun 2017 02:13 AM PDT

I'm not sure if this is the right subreddit, but here goes; When an object is accelerating at a significant speed, can I compute the time dilation effect by using the average velocity of the object while it's accelerating?

(My understanding of physics is basic, please don't crucify me if I make glaring mistakes) Lets say I have an object accelerating at a rate of 2000 g's to .8c (takes around 204 minutes relative to the object), and I wanted to figure out the dilation of time while it's accelerating. My intuition (and my 2 in AP Physics) tells me that I can simply divide the final velocity by 2 (.4c), and use that in the equation in the time dilation equation 1/(Square root of (1-( v2 )/( c2 ))).

So substituting v for .4c and solving like that gives me 1/.774, which when figuring the total time dilation gives me 263 minutes total for an outside observer timing the total length of time it took to accelerate to .8c. I cannot see any flaws in my math, and yet I feel like this answer just isn't right because it seems too simple. Can anyone tell me if I'm on the right track with this?

submitted by /u/RobbieXD
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How is the risk of earthquakes determined?

Posted: 12 Jun 2017 07:57 PM PDT

I was reading about various natural disasters which got me thinking about how we go about understanding which faults are under particularly sever stress or are points or areas at high risk for earthquake.

I assume the question has been asked before but a quick search didn't show what I was asking so if you have a link to a previous thread where this is discussed that would be sufficient.

submitted by /u/dovetc
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Where exactly are the nodes of a free vibrating rod?

Posted: 12 Jun 2017 07:45 PM PDT

According to one source the nodes of a vibrating rod are about 22% from either end.

Why "about 22%"? Unfortunately they don't give any explanation and I could only find calculations for rods that are fixed at one or both ends. I wonder: What is the exact number for a free vibrating rod and how can it be calculated? If the middle of the rod and both ends are antinodes (i.e. points with maximum displacement), shouldn't the nodes be exactly 25% from either end of the rod? Why is this not the case? What am I missing?

I am asking because I want to build wind chimes and need to find the right spot to suspend the tubes.

submitted by /u/Sidiabdulassar
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Why is a grossly over expanded nozzle more efficient than a slight over expansion?

Posted: 12 Jun 2017 07:38 AM PDT

So I came across this when I was doing some gas dynamics research, and I am trying to remember back to my high speed aerodynamics class. A grossly overexpanded nozzle moves the oblique shocks at the exit into a normal shock that slowly moves into the nozzle, while a slight overexpansion has oblique shocks outside the nozzle. Is a grossly overexpanded more efficient because once that normal shock is within the nozzle, all flow pressure increases within the nozzle itself despite it separating from the nozzle wall? With a lot of shock patterns it seems like there is a normal shock some distance from the exterior of the nozzle, followed by a shock diamond pattern of obliques and expansion waves, but I would have thought that getting as close to ideal full expansion would reduce change in entropy and provide maximum thrust.

I came across this claim that grossly over expanded was more efficient than slight over expansion (while not as efficient as ideal expansion) so I would just like some clarification on this.

submitted by /u/Funkit
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What did the invention of computing do for Mathematics?

Posted: 13 Jun 2017 12:52 AM PDT

I was recently watching a numberphile video about Fermats last theorom and Ken Ribbet mentions about writing on the first Mac he got.

That prompted me to wonder what did the invention of computing do for mathematicians when they became more readily available? Did it really only help in the speed of the calculations therefore increasing the speed at which you could solve a particular problem or did it revolutionise it or simply didn't change alot?

I know now that computing can be used to compute simulations and such.

Thanks a lot for any answers. I'm not a mathematician in anyway shape or form.

submitted by /u/Jbstargate1
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You can use the inverse of addition, multiplication, and exponentiation to expand the set of numbers you work with: natural numbers -> integers -> rationals -> reals -> complex numbers. Why does this pattern suddenly stop with exponentiation?

Posted: 12 Jun 2017 10:03 AM PDT

If you allow subtraction on the natural numbers, then you have gaps that are filled by the rest of the integers. If you allow division on the integers, you have gaps that are filled by the rest of the rationals. If you allow roots, you have gaps that are filled with the rest of the reals and then the complex numbers.

Yet from what I understand, there's no such gaps in the complex numbers. Why wouldn't the inverse of tetration continue this pattern?

submitted by /u/heyheyhey27
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Why does a liquid run down the side of a glass when pouring it?

Posted: 12 Jun 2017 09:51 AM PDT

When I pour a liquid from a mug into another container, it runs down the side of the mug. Why does this happen?

submitted by /u/GranttH
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Why is it cold in space but temperatures differ on planets?

Posted: 13 Jun 2017 04:02 AM PDT

There is an absolute zero, but why isn't there an "absolute hot"? If nothing can travel faster than the speed of light, wouldn't "absolute hot" be the heat of a thing assuming the molecules in the thing are traveling at the speed of light?

Posted: 12 Jun 2017 11:10 PM PDT

Because heat is caused by things moving fast. Nothing can travel faster than the speed of light. Therefore, the hottest a thing can get is if the molecules are traveling at the speed of light, right?

submitted by /u/Pandemic21
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Monday, June 12, 2017

Why can't I remember a smell or taste the same way I can an image or a sound?

Why can't I remember a smell or taste the same way I can an image or a sound?


Why can't I remember a smell or taste the same way I can an image or a sound?

Posted: 11 Jun 2017 09:05 PM PDT

For sounds and images, I'm able to replicate those sense data in my head. But for tastes, smells, and touches, I can only remember descriptions of that sensation. For example, my favorite food is ramen and I'm unable to simply produce the taste of ramen in my head - I can only remember that it is savory and salty. Though it seems that I am able to compare tastes and smells (I know one ramen tastes differently from the next, even if they may both be salty and savory). Does this mean I can subconsciously replicate those sense data? Thanks.

submitted by /u/TheRoyalty
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If dry ice is made of CO2, and CO2 is transparent, why does it produce a white fog?

Posted: 11 Jun 2017 01:18 PM PDT

Is there a scientific explanation for the eerie silence people describe before large storms?

Posted: 11 Jun 2017 01:18 PM PDT

[Biology] Do birds of a flock obey some sort of hirearchy? Is there an "alpha" bird or birds?

Posted: 11 Jun 2017 06:27 PM PDT

Woke up today to the sound of some Kookaburras (not that they're necessarily a bird that flocks) outside my window (Australian here) and I was wondering how birds of a flock might interact with each other as far as some pecking order (no pun intended, seriously) is concerned?

submitted by /u/docvitch
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Are there error correcting codes in thermodynamics?

Posted: 12 Jun 2017 04:55 AM PDT

In information theory there are methods for detecting and correcting errors in the transmission of information, and since thermodynamics has proven equivalence with information does the same thing exist in thermo? If so, what is the physical meaning?

submitted by /u/Bahatur
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Why are hybrid animals like Ligers and Mules born sterile?

Posted: 11 Jun 2017 02:35 PM PDT

I've heard it is an imbalance of chromosomes from the different species that isn't so different that they can breed in the first place but different enough that their offspring can't produce eggs or sperm, but why is this?

submitted by /u/TheMysticGed
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How many dimensions are out there? 10 or 24 or more?

Posted: 12 Jun 2017 04:45 AM PDT

I have read about 10 but is 24 just a theoretical number?

submitted by /u/vaibhavk1
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Why was Kalium renamed to Potassium?

Posted: 12 Jun 2017 04:36 AM PDT

How does a violent thunderstorm or tornado cause the sky to appear green?

Posted: 11 Jun 2017 01:53 PM PDT

Do communication waves interfere with each other?

Posted: 12 Jun 2017 12:46 AM PDT

I saw almost everyone in a conference hall with their cellphones out, watching videos and such. Do cellphone signals and similar signals interfere with eachother? How is it that large amounts of data can be so accurately directed to different devices?

submitted by /u/MakitBunDem
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How can animals detect water when we are taught that water doesn't have a scent?

Posted: 12 Jun 2017 12:40 AM PDT

My hypothesis is that some animals don't detect water, but actually detect the effects water has on the environment in which it is found, for example minerals in water due to the effect of erosion or the increased vegetation surrounding water sources.

submitted by /u/JohnathanTeatime
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What was the size of the very early universe?

Posted: 11 Jun 2017 02:01 PM PDT

Howdy,

I'm reading Neil de Grasse Tyson's "Astrophysics for People in a Hurry," and he writes something that is driving me nuts regarding the size of the very early universe.

For those not familiar with the book, the opening chapter starts with the Big Bang, and takes you through all of the things that are happening with quarks, leptons, hadrons, etc. He describes all these things and says stuff like, "A billioninth of a second has passed." It's a very compelling literary tool.

But then he writes this: "By now, one second of time has passed. The universe has grown to a few light-years across..."

Here's what is bothering me: if only a second of time has passed, how could the universe have expanded to a few light years across? How could any of those early particles have traveled further than a light second?

Presumably at this point the particles were all limited to traveling at the speed of light. So after one second of time, wouldn't the diameter of the universe (assuming it was basically a sphere) be 2 light seconds?

submitted by /u/Avoid-The-Clap
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Can computers read a book and answer our questions beyond basic keyword searches?

Posted: 11 Jun 2017 11:46 PM PDT

Questions like:

  • list the members of the Fellowship (LOTR)

  • plot explanation

  • complex religious problem by reading Bible or Quran

submitted by /u/iBzOtaku
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Why don't our teeth heal?

Posted: 11 Jun 2017 07:38 PM PDT

Why do we need fillings for our cavities, after all shouldn't evolution have caused that our teeth can regenerate like our bones and skin?

Idk if this is the same but; We see this by some rodents who's ameloblasts don't die after their teeth grow. Though they need to constantly gnaw at things, to keep their teeth at the proper size and shape, this seems to be a much more practical solution ("evolution-wise") than not healing at all.

submitted by /u/webs1357
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For what situations would the 3rd derivative (and beyond) of displacement, eg jerk, be applied or used?

Posted: 12 Jun 2017 12:24 AM PDT

How do atoms join together?

Posted: 12 Jun 2017 02:16 AM PDT

Eg. Hydrogen + carbon dioxide - water. How does the hydrogen and carbon dioxide join together?

submitted by /u/willy_wonka_8391
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Can someone please explain holography to me? Just the last step; I can't find the explanation anywhere on the internet.

Posted: 11 Jun 2017 12:01 PM PDT

OK, so I understand interference, coherence and all that kinds of things.

I want to learn about holography, so I open its article on Wikipedia and read. It's all OK until in the "How it works" section, in the "Process" paragraph, I find this:

This missing key is provided later by shining a laser, identical to the one used to record the hologram, onto the developed film. When this beam illuminates the hologram, it is diffracted by the hologram's surface pattern. This produces a light field identical to the one originally produced by the scene and scattered onto the hologram.

How? So I have an interference pattern, I have somehow frozen it. Then I shine a light on it. Why does the light shining on the interference pattern produce the other beam which created the pattern? Thanks.

submitted by /u/elmiraguth
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Where do neutrons come from?

Posted: 11 Jun 2017 12:56 PM PDT

If the universe was proton soup after the Big Bang and these protons began gathering in large clouds of hydrogen which due to gravity started to compress and heat and fuse into other elements like helium, where did the neutrons come from?

submitted by /u/lli32
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How can a non radioactive material have radiation?

Posted: 11 Jun 2017 01:38 PM PDT

Assume I'm exposed to radiation, how do I become radioactive? From my understanding radiation are gamma beta and alpha Rays. For cases like visiting Chernobyl I should be safe after leaving and cleaning any contaminated clothes, but people can measure radioactivity on someone's body, that doesn't make sense

submitted by /u/hdjsiwwnwn
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Are there any reptiles that prefer really dark places?

Posted: 11 Jun 2017 11:44 PM PDT

I'm worldbuilding something and I have a species of REPTILIAN HUMANOIDS who evolved as a species on the night side of a tidal locked planet, and as such anything beyond the most minimal amount of light actually damages their skin along the lines of xeroderma pigmentosum

As far as I know there's no reptile or animal that's actually physically harmed by light, though please let me know if there is. What I'm looking for is any reptile or other animal with an extreme dislike for light, but isn't nocturnal.

submitted by /u/DerpyDaymare
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Does light travel faster through hot air than it does cold air?

Posted: 11 Jun 2017 10:32 AM PDT

If you keep flying a plane upwards what happens?

Posted: 11 Jun 2017 11:42 AM PDT

How do atoms convert to energy?

Posted: 11 Jun 2017 11:23 AM PDT

If matter and energy and interchangeable, how do atoms convert to photons?

submitted by /u/FattyMigs
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