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Monday, September 10, 2018

Why didn't the leak in the ISS vent all the air immediately?

Why didn't the leak in the ISS vent all the air immediately?


Why didn't the leak in the ISS vent all the air immediately?

Posted: 09 Sep 2018 07:32 AM PDT

I assumed that because there's no air in space, and lots in the ISS, it would shoot out incredibly fast. Is my assumption just plain wrong or is there more at play?

submitted by /u/Irish_Potatoes_
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If the brain recovers from depression, than are there obvious before and after structural changes?

Posted: 09 Sep 2018 07:40 PM PDT

Would a proton orbit an antiproton?

Posted: 10 Sep 2018 06:15 AM PDT

Would they just annihilate? If so, what would they release?

Or would the residual strong force tear them apart? Once torn apart, would their quarks just annihilate, or would they settle into mesons?

If this did happen, what would it be called? Protonium, or an just an exotic hydrogen-2 cation?

Do we even know any of these things?

And; most importantly; what exactly keeps antiparticles in orbit? Shouldn't their electric attraction just pull them together and annihilate them?

(Sorry bout the length but this has literally kept me up over the last few nights. Help!!!)

submitted by /u/Da_Gr8_M8
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Is lux or candela/m2 a more appropriate unit for quantifying the amount of light that reaches someone's eye?

Posted: 10 Sep 2018 12:47 AM PDT

I am a little confused about which unit is most appropriate for my purposes. I am measuring pupil diameter using a remote eye tracking device mounted to a computer monitor. I am adjusting light via changes to computer screen luminance via adjusting the colour of the screen (e.g. white – grey – dark grey). There are going to be other lights in the room as well which will stay constant. My main goal is to measure how much light that reaches a person's eye in a given condition. Is it most appropriate to measure candela/m2 or lux in this case? I have found so many conflicting points about the differences between luminance and illumination, regarding which is more appropriate for my purposes. My thinking is that I would want to measure lux because I am not only interested in the amount of light that is emitted from the computer screen, but all of the light in the room that reaches a person's eyes. I just happen to be manipulating this via the computer screen. I am still left with a bit of a nagging feeling though as I am not 100%. Any help is greatly appreciated.

submitted by /u/joopunderfire
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Would dolphins echolocation work out of water? How different would it be from bats echolocation?

Posted: 09 Sep 2018 04:49 PM PDT

Would a dolphin "see" the way it is used to when using echolocation out of water?

submitted by /u/NumbPlatypus
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How is it possible that we can sleep too much? Shouldn't we wake up the moment our body has rested enough?

Posted: 09 Sep 2018 12:20 AM PDT

How is the discrete particle aspect of photons consistent with cyclotron radiation?

Posted: 09 Sep 2018 04:54 PM PDT

Speaking from a certain level of layman intuition, I can picture how a single charged particle spiraling around in a cyclotron can emit EM waves like this. What I'm having trouble understanding is the consistency between this wave model, and the discrete nature of photons, specifically in the case of cyclotron radiation.

As I understand it, you could detect individual discrete photon energy packets arriving at a detector at various times from a spiraling (accelerating) charge in a cyclotron. Does this discrete particle aspect indicate that there are instances in time when the accelerating charge is not producing a photon? Or else it seems like it would have to be emitting an infinite amount of photons (and energy) at every moment in time to mirror the continuous nature of the wave-like behavior in the gif?

submitted by /u/noun_exchanger
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What are the difference of bipolar and depression?

Posted: 09 Sep 2018 07:37 PM PDT

Is intelligence hereditary?

Posted: 09 Sep 2018 10:46 AM PDT

Why does each planet have exactly 5 Lagrange points?

Posted: 09 Sep 2018 04:52 PM PDT

I can understand the location of L1, since it is located on the line segment connecting the centers of the Sun and the planet in question. Could someone explain where the other four should be, and why there are only four more?

submitted by /u/usernamematesout
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What biological 'equipment' does an organism need to feel pain (and can this be exclusive of suffering)?

Posted: 09 Sep 2018 06:20 PM PDT

I'll preface this with the fact that I'm not very educated when it comes to science.

While it's obvious that land animals such as cats, pigs, cows, humans etc are capable of both feeling pain and suffering - I've been looking into bivalves like clams and oysters, and it seems they have a 'basic' brain structure in place. Ganglia, nerve cords e.t.c. Obviously no central nervous system though.

I've seen mixed opinions about whether or not this allows them to feel pain. In the case of clams, the evidence was given that they react to physical stimuli by moving away, in a similar way to mammals (and in a way that plants cannot). This seems to me more in line with sentience than with non-sentient life.

It seems that no-one really knows at this point, but I've heard both sides:

  • "Bivalves are very unlikely to be sentient due to a lack of a central nervous system."
  • "Bivalves' structures share much with sentient animals, so we would do better to err on the side of caution and treat them as such."

Basically, my questions are:

Are bivalves sentient?

What does an organism need to feel pain and/or suffer?

submitted by /u/JamesOfTheYear
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I covered a cast iron pan full of leftovers with aluminum foil two days ago. Today, when I went to reheat the food, I found that the aluminum foil had turned to swiss cheese, dissolving somehow onto the surface of our food! What process just happened here?

Posted: 09 Sep 2018 03:32 PM PDT

If the coriolis effect makes hurricanes/typhoons swirl in different directions, what exactly happens when storms cross the equator? Do they begin to slow and weaken?

Posted: 09 Sep 2018 04:12 PM PDT

How did we find that relaxed electrons emit light?

Posted: 10 Sep 2018 12:24 AM PDT

Why doesn’t thunder happen all at once? Why is the sound spread out?

Posted: 09 Sep 2018 06:06 PM PDT

Does prosopagnosia/face blindness also affect how people see ‘faces’ on animals or is it restricted to humans?

Posted: 09 Sep 2018 01:54 PM PDT

How much power does the average quartz watch use?

Posted: 09 Sep 2018 10:14 PM PDT

So I did a Google search before asking this and couldn't find many solid answers. I'm assuming that the amount of power consumption differs from watch to watch as well as the battery capacity. Can anyone give me an estimate as to how much electricity is usually used to vibrate the quartz crystal to keep the watch functioning? Or at least give me an explanation as to why this question is hard to answer? Thank you!

submitted by /u/geoguy26
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What do pets see toys as? Does a cat see a butterfly on a string as prey? Does a dog see a cuddly toy as another animal?

Posted: 09 Sep 2018 12:43 PM PDT

How much does long-term memory vary across humans?

Posted: 09 Sep 2018 12:01 PM PDT

Do all people have a similar "forgetting rate" of stuff stored in long-term memory or is there a significant variation?

Also, is there a standard measure of long-term memory, aka "memory quotient"?

submitted by /u/falconberger
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Why does blood donation use hard needles unlike IV lines?

Posted: 09 Sep 2018 09:08 AM PDT

It seems that when you give whole blood or platelets, they stick you with (a) rigid needle(s) and leave them in your vein(s). If you move too much, the needles can work their way out and cause bruising. But when you get an IV, they stick you with a rigid needle, but then leave only a flexible tube in your vein. Why don't they use flexible tubes for blood donations?

submitted by /u/PCup
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How was the experiment that lead scientists to found or confirm the universal gas constant?

Posted: 09 Sep 2018 08:20 PM PDT

I know the constant (R) was found as a combination of some chemistry laws including Avogadro's, Gay-Lussac's and Boyle's and that it was determined empirically but there had to be one first experiment to found it or at least to confirm it.

submitted by /u/dani7447
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Can acoustic and optical phonon branch intersect?

Posted: 09 Sep 2018 10:04 AM PDT

I studied that in the case of a diatomic chain in 1D, when the two atoms have the same mass, the optical and acoustic phonon branch intersect at some point. Now I was wondering if this is true also in the case of a 3D material, like diamond (that can be seen as a fcc lattice with 2 carbon atoms per cell). I've done a DFT simulation, but the resulting dispersion relation seems to negate this possibility. Did I made some mistake in the simulation or exists a gap between the two branches?

submitted by /u/Background_Jackfruit
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What do the numbers on oil mean?

Posted: 09 Sep 2018 03:46 PM PDT

What are the numbers on engine oil actually measuring? I know the #W is winter and the next number is at 100C, but shouldn't viscosity go down as temperature rises? And is a bigger range better or a smaller range better?

submitted by /u/razorOO85
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Do Solid State Drives have any vulnerabilities that can be compared to how destructive magnetic fields are to HDDs?

Posted: 09 Sep 2018 08:51 AM PDT

Sunday, September 9, 2018

How do we know what dinosaurs look like?

How do we know what dinosaurs look like?


How do we know what dinosaurs look like?

Posted: 08 Sep 2018 09:50 AM PDT

Furthermore, how can scientist tell anything about the dinosaurs beyond the bones? Like skin texture and sounds.

submitted by /u/weeblybeebly
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Questions about black-hole mergers?

Posted: 08 Sep 2018 03:59 AM PDT

As infalling gravitational singularities orbit each other faster and faster around a certain point, they produce waves that we've measured: https://www.youtube.com/watch?v=TWqhUANNFXw

I was wondering what sort of geodesic they form in the microseconds before merger...as the event horizons draw nearer and pull space-time between them...is it a sort of torus, or elongated sphere? What would happen to certain particles, or even photons, trapped between them moving in an insanely fast figure 8; would they be accelerated out in escape velocities just before the merge? Does that generate a sort of 'radio blast' that would follow millions of years after we detected the gravity wave due to redshift?

submitted by /u/Riven55555
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Would solar systems with young stars have more radioactive isotopes?

Posted: 08 Sep 2018 10:02 AM PDT

I was just thinking about how long it took for complex life on our planet to form. I had the thought that with more radioactivity from isotopes there would be more mutations which would make it difficult for multicellular organisms to reproduce without passing on mutations.

Like if we seeded life in young solar systems organisms with diploid cells would be more resilient than haploid bacteria at least but I assume there is a sweet spot in how much radioactivity is needed for complex life to thrive over millions and millions of years.

I haven't taken any advanced science classes yet but am I wrong in my understanding?

submitted by /u/nopasties
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How do we know How much lightyears a star is away from us?

Posted: 09 Sep 2018 01:21 AM PDT

Even weirder: How do we even know What They are Made of and How hot They are and all that kind of stuff?

submitted by /u/RoyalRien
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If gravitons are extremely hard to detect if they’re real, is there any other way to experimentally verify their existence other than direct observation?

Posted: 09 Sep 2018 02:52 AM PDT

Why are our ring fingers less dexterous than other fingers?

Posted: 08 Sep 2018 11:24 AM PDT

We can move fingers like our pointer finger and pinky pretty much independently from other fingers. That isn't the case with our ring fingers. Why is that?

submitted by /u/EmilyClaire1718
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Can entangled photons from spontaneous parametric down-conversion (SPDC) be generated without a UV pump laser? Can other wavelengths be used? Would specific crystals and angles be required?

Posted: 09 Sep 2018 01:08 AM PDT

So I'm very new to nonlinear optics and I discovered that using UB lasers and either barium borate (BBO) or potassium dihydrogenphosphate (KDP) crystals one can create entangled photons via the process of spontaneous parametric down-conversion. My question is, would this also be possible with other laser wavelengths? I don't really see why not in principle, though different crystals may be necessary? If you can tell me more about this or point me to some reading material, that would be greatly appreciated :) !

submitted by /u/Kardinality
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Where does fluid that gets 'locked' into your ear go?

Posted: 08 Sep 2018 04:24 AM PDT

I've been using ear drops to clear wax in my ear and sometimes the drops disappear for more than a day before they come trickling out. Where have they gone? They can't get beyond the ear drum can they?

submitted by /u/freewaterfalls
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Exoplanets - is it lucky to find one?

Posted: 08 Sep 2018 11:01 AM PDT

I know that as of March this year, over 2,300 confirmed exoplanets have been discovered, but considering the methods by which they're discovered, surely we're very lucky to find any at all. Transits of Venus arguably happen every 243 years, and aren't transits exactly how we discover exoplanets? Or is there another way we can search for them that doesn't rely on the exoplanet placing itself between its host star and us?

submitted by /u/BodaciousBuns
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How is a stamped hologram on a credit card different from other holograms, such that the image can be cut in half?

Posted: 08 Sep 2018 06:19 PM PDT

Through reading about holograms, I have learned that a hologram cut in half should show the whole image, but through a more limited perspective. But this is not how the hologram on my credit card behaved when I cut it in half. I just got half of the image, as you would with a photograph.

Why would this happen with this sort of hologram and not with others?

Thanks.

Image: https://i.imgur.com/njuyVLm.jpg

submitted by /u/Sword_of_Apollo
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What’s the mechanism of muscle memory? Will cut and healed muscle keep its memory?

Posted: 08 Sep 2018 08:59 AM PDT

Atoms have roughly the same number of protons and neutrons. How much of a coincidence is that?

Posted: 08 Sep 2018 11:01 AM PDT

Does every known animal require sleep?

Posted: 08 Sep 2018 01:53 AM PDT

Is vision universally optimal or optimal for us?

Posted: 08 Sep 2018 01:47 AM PDT

So the "visual spectrum" for humans is 700-400 ish nm light. I know certain insects see in the ultraviolet band as well. I would assume some animals see somewhat lower into the infrared. My question is, what makes that narrow portion of thr em spectrum optimal? Is it optimal? Or did it evolve because other life interacted with that band and so early photoreceptors evolved to sense it? Would it be conceivable that some alien species sees in microwaves, for instance and has named small slices of that the way we name colors? So for them our visual spectrum would be lumped in with the "infra red" or "radio" bands?

submitted by /u/rao000
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Will a car accelerate quicker driving with the rotation of the earth or slower going against the rotation of the earth or does it have no effect?

Posted: 08 Sep 2018 05:26 AM PDT

When we do maths, what goes on in the neurons in our brains?

Posted: 08 Sep 2018 04:28 AM PDT

I believe computers have transistors that directly input and output answers when doing maths like addition or multiplication, but what goes on in our neurons when we do maths that makes us much slower than computers?

submitted by /u/corimaith
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Why do things like laughing really hard and yawning make your eyes water?

Posted: 07 Sep 2018 10:16 PM PDT

Saturday, September 8, 2018

How does the area of a black hole's event horizon change with respect to its mass increase?

How does the area of a black hole's event horizon change with respect to its mass increase?


How does the area of a black hole's event horizon change with respect to its mass increase?

Posted: 07 Sep 2018 06:45 PM PDT

I understand that the mass of a black hole increases by the same amount of the in-falling mass. Is the (spherical?) surface of the event horizon simply related to the BH's mass as it is to its "volume?" In other words, if the BH were a physical object made of some non-compressible material, say water, for every extra drop that joined the BH its volume, and therefore surface, would increase by a given amount. Double the mass/volume and the surface would increase by (I think) 2/3.

Is that the same in an actual BH?

Is the event horizon always spherical? Even in rotating BHs?

submitted by /u/wearsAtrenchcoat
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How populated was the earth with Dinosaurs during the Triassic, Jurassic, Cretaceous periods?

Posted: 07 Sep 2018 08:29 AM PDT

If I were to DeLorean back to the age of the Dinosaurs, what would my chances of seeing a small/medium/large dinosaur in any encounter? Would driving anywhere be like a safari in Africa or would you really have to seek out the creatures? How different was the Triassic, Jurassic, and Cretaceous periods?

submitted by /u/coolmandan03
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Can somebody explain the wall effect in a ball-drop viscometer?

Posted: 08 Sep 2018 02:48 AM PDT

How can our brains be so energy efficient when compared to computers, and why do they not overheat?

Posted: 07 Sep 2018 08:14 AM PDT

Why does latent heat of phase change exist?

Posted: 07 Sep 2018 02:53 PM PDT

TL;DR I think my biggest problem is I don't know where the latent heat is stored, if not in the combined minute motion of the molecules and atoms (temperature).

Is it the fact that a substance gradually converts to the new phase? Like when boiling water, the water sits at boiling temp while the most energetic molecules fly out, keeping the water at constant temperature? But if those steam molecules are still considered part of the overall volume of water being measured, and temperature is the average kinetic energy of the molecules, they would increase the temperature, so I assume that's not the case, as (thermal energy, temperature) graphs show a clear plateau at each phase change. Do gas and liquid molecules contribute less of their kinetic energy to temperature than the molecules in a solid? Or does this gradual conversion to steam not happen until the temperature passes the latent heat plateau? If so, back to my TL;DR: where does the latent heat go so that it comes back with the opposite phase change?

If it is related to entropy, I would also like an explanation of that. I know gas cools as it expands and rubber bands cool down when they stop stretching, both of which I've heard explained with entropy, but it still doesn't make sense to me.

submitted by /u/Overtime_Lurker
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Is the Hydronium ion just as likely to occur as Ammonium Ion during a basic water and ammonia reaction?

Posted: 07 Sep 2018 10:27 AM PDT

This is probably a simple question but I'm struggling with understanding basic trends in chemical reactions.

The equation in question: "NH3 + H2O = NH4+ + OH-"

Why is the ammonium ion and hydroxide the product of this (reversible) reaction? Why does the hydrogen pair with the nitrogen over the oxygen? Is H3O+ also created in a lesser quantity? Is it related to oxygen being more electronegative than nitrogen?

Thanks

submitted by /u/Next_Mushroom
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In order to escape a predator, a prey animal that moves in a herd does not have to outrun the predator to survive - just the rest of the herd. Are there any species that are known to sabotage one another while fleeing a predator to ensure their own survival?

Posted: 07 Sep 2018 05:45 AM PDT

whats the deal with the reaction we have when we hear scratching on a chalkboard or a fork across the plate. Why do we do the thing we do? Also why does simply thinking about it sometimes trigger it?

Posted: 07 Sep 2018 07:26 AM PDT

What would the earth look like with a 0-degree axial tilt?

Posted: 07 Sep 2018 08:10 AM PDT

Obviously there would be no seasons, but what else? Would the temperature differences between the equator and the poles be much more severe?

submitted by /u/badskeleton
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What is the theoretical limit of CPU speed?

Posted: 07 Sep 2018 06:56 AM PDT

When it comes to speed we say speed of light is the limit.

In similar fashion what would be the maximum of speed of a CPU if only restricted by speed of light?

What would be the maximum FPS a video camera can capture pictures?

submitted by /u/jarjarbings
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How can you reduce power of microwave oven?

Posted: 07 Sep 2018 02:48 PM PDT

Isn't the wave energy of a given lenght and frequency constant? How can we reduce the power of a 1000 W microwave? I mean the frequrncy os 2.5 GHz, the wavelength i suppose is constant also. What changes then? What's different in an 600 W and 1000 W microwave oven?

submitted by /u/Wermikulit
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Can someone explain hair to me?

Posted: 07 Sep 2018 06:42 AM PDT

I have a number of questions that all fall under the umbrella of "hair stuff."

  1. What causes the different colours?
  2. Shape and style? It's a running joke that white barbers don't know how to cut black hair, but why is it different?
  3. What's up with old people having bushier eyebrow, ear, and nasal hair?
  4. Why is hair where it is on the body, and why is it different lengths, textures, and colours in those places?
submitted by /u/FOR_PRUSSIA
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