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Tuesday, July 10, 2018

AskScience AMA Series: I'm Dr. Laurie Santos, Professor of Psychology and Cognitive Science at Yale University. My lab studies what makes the human mind special by examining how monkeys, dogs, and other animals think about the world. AMA!

AskScience AMA Series: I'm Dr. Laurie Santos, Professor of Psychology and Cognitive Science at Yale University. My lab studies what makes the human mind special by examining how monkeys, dogs, and other animals think about the world. AMA!


AskScience AMA Series: I'm Dr. Laurie Santos, Professor of Psychology and Cognitive Science at Yale University. My lab studies what makes the human mind special by examining how monkeys, dogs, and other animals think about the world. AMA!

Posted: 10 Jul 2018 04:00 AM PDT

Hi reddit! I'm Dr. Laurie Santos, the Director of the Comparative Cognition Laboratory at Yale and the Canine Cognition Center at Yale. My research explores the evolutionary origins of the human mind by comparing the cognitive abilities of human and non-human animals, in particular primates and dogs. I focus on whether non-human animals share some of the cognitive biases that plague humans. My TED talk explored whether monkeys make the same financial mistakes as humans and has been viewed over 1.3 million times. I was voted one of Popular Science Magazine's "Brilliant 10" young minds, and was named in Time Magazine as a "Leading Campus Celebrity".

My new course, Psychology and the Good Life, teaches students how the science of psychology can provide important hints about how to make wiser choices and live a life that's happier and more fulfilling. The course recently became Yale's most popular course in over 300 years, with almost one of our four students at Yale enrolled. The course has been featured in numerous news outlets including the New York Times, NBC Nightly News, The Today Show, GQ Magazine, Slate and Oprah.com. I've also developed a shorter version of this course which is available for free on Coursera.

I'm psyched to talk about animal minds, cognitive biases or how you can use psychological sciences to live better. I'll be on around 4 or 5pm EST (16/17 UT), AMA!

submitted by /u/AskScienceModerator
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Would a tsunami have a “pull” like a normal wave?

Posted: 09 Jul 2018 05:51 PM PDT

Would it have a stronger pull or the same, and would it get stronger the bigger the wave was?

submitted by /u/MewMeeowMew
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Why do house cats have slit pupils but big cats (lions, tigers, cheetahs, etc) have round pupils?

Posted: 10 Jul 2018 01:44 AM PDT

How did the study linking MMR vaccine and autism come to be published in The Lancet if it was obviously flawed?

Posted: 10 Jul 2018 01:07 AM PDT

I would have thought that a reputable journal of the calibre of The Lancet would vet any article submitted for publication very rigorously.

submitted by /u/trumpeting_in_corrid
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How does a "blood pressure" manometer measure the preasure of your blood?

Posted: 09 Jul 2018 03:09 PM PDT

The manometer cuff pressure plus atmospheric pressure is measured, and the cuff pressure is a response from squeezing your arm. By that logic, aren't we measuring the pressure of your arm as a whole (including other fluids/water, muscles, etc.)?

submitted by /u/AdventureMan5000
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When organs are surgically removed, what happens to the space they were previously in?

Posted: 10 Jul 2018 04:23 AM PDT

Can people end up with a 'dent' in their body? What prevents other organs moving around causing problems?

submitted by /u/mwnciau
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Does knowing that you have Bi-Polar disorder lessen the affects of having the disorder?

Posted: 10 Jul 2018 07:20 AM PDT

It seems to me that knowing that I had the dis-order would at least help to lessen (not eliminate) the affects. Or is it so debilitating that it doesn't matter?

submitted by /u/toweringmelanoma
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Does the ozone layer rotate with the earth?

Posted: 10 Jul 2018 03:45 AM PDT

Also: is the ozone layer repairable?

submitted by /u/Remri
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why do bug bites itch?

Posted: 09 Jul 2018 03:54 PM PDT

Ok so I did a bunch of yardwork without applying some bug spray first and I have a ton of bites. My question is why do bug bites itch? Wouldn't it be more advantageous for the host to never even know you were there? I am curious why they itch both as a literal means such as what chemicals etc... and what is the advantage to that species to do that.

submitted by /u/bikersquid
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What causes the neck pain that we associate with sleeping the wrong way?

Posted: 10 Jul 2018 07:35 AM PDT

How/where are neurotransmitters destroyed? Do reuptake-inhibitors increase destruction rate?

Posted: 09 Jul 2018 11:32 PM PDT

My basic understanding is that neurotransmitters are stored in vesicles inside the pre-synaptic neuron. Upon activation they are released into the synaptic cleft, where they may or may not bind to receptors in the post-synaptic neuron, and afterwards they are reuptaken back into the pre-synaptic neuron.
So it seems neurotransmitters are never lost or destroyed, yet they are constantly produced in the brain, so I'm obviously missing something.

Does degeneration naturally occur in the vesicle/pre-synaptic neuron? Do neurotransmitters in the synaptic cleft sometimes get lost or ejected somewhere else? If so - do re-uptake inhibitors increase the rate of loss of neurotransmitters? (as each neurotransmitter presumably stays in the "danger zone" of the synaptic cleft longer, giving it more chance to be eliminated).

(In case this varies depending on the specific neurotransmitter - I am mostly interested in dopamine, and to a lesser extent in serotonin)

Thanks.

submitted by /u/therealsillyfly
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I am a firefighter with a fluid dynamics question. When splitting a single 4" diameter supply line to two separate supply lines, why would I get more water from splitting to one section of 4" and one section of 3", as opposed to two sections of 4"?

Posted: 09 Jul 2018 07:01 PM PDT

So were were practicing filling tankers (trucks that carry 3,000 gallons of water each), and noticed something interesting. I will explain our setup. So we had a 10' length of 4" supply line coming off of a hydrant w/ ~60 psi of pressure. There was a manifold on the end of that section of 4" that splits it into two supply lines. Our initial setup was to run 50' of 4" off of one side and 50' of 3" off of the other. When filling two tankers simultaneously we noticed that both tankers were filling rather predictably. The one with the 4" was filling faster and the one with the 3" was filling at about half that rate.

When we had the materials necessary, I "upgraded" the 50' of 3" to another 50' section of 4". Now we have two 50' sections of 4" coming off of the manifold. This is where the confusing bit happened. When I would hook up and fill two tankers simultaneously, one of the tankers would get almost all of the water, and the other would get nearly nothing, until the first line was shut down. No one has been able to explain this to me. There are two essentially identical supply lines coming off of the manifold, why would one be favored so heavily. And why would the 3" line allow more water flow when partnered with the 4"?

Sketch of setup

submitted by /u/Loudsound07
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Why is it that small cats hiss while big cats, such as lions, roar? Do big cats have the ability to hiss?

Posted: 10 Jul 2018 04:52 AM PDT

Is it possible to break the speed of light in water or some other medium?

Posted: 09 Jul 2018 11:39 PM PDT

The speed of light in a vacuum is just shy of 300,000,000 m/s, and physics tells us this is something of a cosmic speed limit. Nothing is able to travel faster than the speed of light. But what about the speed of light in something other than a vacuum? What is the speed of light in water? And if you could eliminate problems of resistance, is there anything in the laws of physics that says you couldn't surpass the speed of light in water as long as you stay under the 300,000,000 m/s speed limit? What would happen if you did?

submitted by /u/Justinsetchell
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Does pregnancy prolong the time before a woman gets menopause?

Posted: 10 Jul 2018 05:52 AM PDT

Females are born with all the eggs they'll ever have. But pregnancy is nine months long, nine months the body won't release an egg. If the woman nurses, it could sometimes be even longer. If fewer eggs get released, does it delay the onset of menopause? Or does it just that mean more eggs are "left behind" to go bad?

submitted by /u/PhoenixTears14
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If you get an arm amputated (or another part of your body), you'll probably feel a phantom pain "in" this amputated arm. Can painkillers reduce/eliminate the pain, even though it's only in your head, or won't they have any effect?

Posted: 10 Jul 2018 05:47 AM PDT

Is there anyway we can accurately guess or know dinosaurs life span?

Posted: 10 Jul 2018 06:41 AM PDT

See title

submitted by /u/Sprawl87
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In the lifespan of one female in a pride of lions, how many males on average would she have cubs by?

Posted: 10 Jul 2018 02:14 AM PDT

or how often do male lions have to face a challenge from a new male?

submitted by /u/catcaste
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When you drive around in your car, does the air inside slosh around like water would in a moving container?

Posted: 09 Jul 2018 08:33 PM PDT

Why does the descent from the Botai's horses prove that Przwalski Horses are not wild but feral?

Posted: 10 Jul 2018 06:56 AM PDT

So earlier this year (early 2018, possibly already in late 2017) a study was published, were researchers analysed the DNA of Horse-remains found in settlements of the Botai (a culture in northern Kazakhstan, about 5000 years ago. So about 3000 BC?). They wanted to prove that the Botai-Horses are the ancestors of our modern domesticated Horses, yet found out they are rather the ancestors of the Przwalski Horses. Thus they came to conclusion that the Przwalski Horses are no true wild horses but rather feral horses, like Mustangs. At least that's how I understand it from reading on several News Pages for example here on National Geographic

I'm more a historian than a biologist, so I'm no expert in this topic and I haven't read the actual study, but I can't really follow that conclusion and I've got some questions:

So how I understand it, the idea is there once were wild horses. these were domesticated by the Botai, and then these domesticated horses ran away and became feral. These feral Botai Horses are the Przwalski Horses. So, when the horses were domesticated, were there no wild horses left? Cause if there were wild horses left, couldn't they have "assimilated" the feral horses?

Does the DNA actually show descent or rather blood relation? Couldn't the similar DNA just mean, that Botai and Przwalski Horses have a common ancestor, but are different branches of the tree? Again with the possibilty that the branches converged after the Botai horses became feral?

Or is it all just blown out of proportion by the journalists and the study says nothing about Przwalskis not beeing considered as wild horses any more?

So, yeah that's it.

Thanks in advance.

submitted by /u/Kolibri8
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If a radio transmission was detected from an intelligent civilization from across the galaxy would it be possible for the government to jam or block the signal so that it would go undetected to agencies such as SETI or whomever is listening for such things?

Posted: 10 Jul 2018 05:13 AM PDT

Does a fetus's newly started heartbeat effectively pump blood?

Posted: 09 Jul 2018 07:05 PM PDT

At a certain point in a fetus's development, it's heart begins to beat. At that point, is the heart's chamber's and musculature formed sufficiently to pump blood, or is the heart just beating because it started beating?

submitted by /u/BagelsToGo
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Are our internal organs sexed so the differences between men and women are noticeable?

Posted: 09 Jul 2018 06:50 PM PDT

I don't mean our reproductives and plumbing, we know about those. I am referring to things the heart and lungs, digestive organs, lymphatic system, eyeballs, teeth, fingernails, veins, blood or boogers.

We're familiar with the skeletal differences (brow, cheekbones, jaw, hands and feet) and the general differences in metabolic rate, lung capacity, muscular and fat distribution but I was wondering if there were differences in say the liver, or the uvula, vomer or gall bladder, the things that don't normally come up as examples.

I was thinking of the push in recent decades to get more women in to Pharma testing as subjects and how cardiac pain can be missed in women if you're looking for the famous shooting pain in the left arm experienced by men.

Let me give a for instance. Could someone look at a liver and say 'Yep, it belonged to a man' or liver tests. I'm using the liver because it's a fascinating organ.

Please and thank you.

submitted by /u/Mr_Gaslight
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I can see the moon at daytime but not stars? Why is that

Posted: 10 Jul 2018 03:58 AM PDT

Monday, July 9, 2018

What are the current limitations of desalination plants globally?

What are the current limitations of desalination plants globally?


What are the current limitations of desalination plants globally?

Posted: 09 Jul 2018 02:50 AM PDT

A quick google search shows that the cost of desalination plants is huge. A brief post here explaining cost https://www.quora.com/How-much-does-a-water-desalination-plant-cost

With current temperatures at record heights and droughts effecting farming crops and livestock where I'm from (Ireland) other than cost, what other limitations are there with desalination?

Or

Has the technology for it improved in recent years to make it more viable?

Edit: grammer

submitted by /u/MrTigeriffic
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What is actually going on when people claim they are "double-jointed"?

Posted: 08 Jul 2018 11:33 AM PDT

What happens to light on opposite sides of intergalactic bodies undergoing the expansion of the universe?

Posted: 09 Jul 2018 05:11 AM PDT

So if two intergalactic bodies are traveling away from each other at or faster than the speed of light, light from one will never reach the other. But what happens to the light on their opposite side? Does light go faster than the speed of light? Or what happens?

submitted by /u/V3NG34NC3
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Why do stars appear to constantly change colour?

Posted: 08 Jul 2018 11:59 PM PDT

I know this is more of a less complicated 'kids question', but I'm honestly not bothered enough to search for it on Google.

Anyway, when ever I look up at the night sky, any star I stare at seems to be constantly changing colours in a rapid flash.

Does this happen because of the way the light refracts in the atmosphere, or are my eyes just fucked and can't process bright colours properly?

submitted by /u/I_Control_The_Sauce
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How is it possible to brute force a password when most computers/websites lock a user out after a low number of incorrect tries?

Posted: 08 Jul 2018 11:27 AM PDT

Why are there more islands in the Pacific Ocean compared to the Atlantic Ocean? What causes this difference?

Posted: 08 Jul 2018 05:17 PM PDT

The Pacific Ocean is significantly older than The Atlantic Ocean, does this have anything to do with the amount of islands each contains? Or does the depth of the oceans play a role in it?

submitted by /u/C0mGussler
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Does the AC frequency affect the molecular conductivity?

Posted: 09 Jul 2018 06:20 AM PDT

I recall reading somewhere that several molecular compounds have different conductivity depending on the frequency of the current; however, I cannot find this anywhere. Does anyone know what is the name of the process when molecules change their conductance based on the frequency of the current?

submitted by /u/StarAvenger
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If black holes have such a strong pull that not even light can escape, how come this is true even when it has the same mass to something else?

Posted: 08 Jul 2018 10:57 PM PDT

I was under the impression that mass is what determines gravitational pull (generally). We orbit the Sun in the way we do because it has the mass of the Sun (or really, we orbit a point created from the gravitational pull of Sun, Earth, and all the other planets and objects and it just happens to be in the Sun, but that's not really relevant I don't think).

However, if the Sun was instead a black hole with the same mass, wouldn't we still be orbiting it the same way? Yet light still can't escape from the event horizon. How can this be if it's coming from an object with the same mass as the Sun?

submitted by /u/uknownada
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Is all of the current absorbed by a CPU converted to heat? Or is there a fraction of in that goes into the computational work?

Posted: 08 Jul 2018 01:15 PM PDT

Not really sure of how to pose this. I studied that cmos tech only consume energy when changing state, which is required for it to work, but does ALL of the energy absorbed goes wasted into heat or is there a part that goes into the "work" made to calculate things?

submitted by /u/puppiesshelter
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Plausibility of a solar shield to combat global warming?

Posted: 09 Jul 2018 03:04 AM PDT

With the news today that we are hitting global records in temperatures and they are increasing year on year without meaningful change to combat global warming I've been wondering about technological solutions.

Wouldn't a 'solar umbrella' at a lagrange point be an effective means of cooling the planet? It would no doubt be highly complex feat but would it work if we could get the material into space?

It seems far more realistic than carbon capture technologies considering the scale and cost and the inefficiencies associated with the technology. At least in my mind.

submitted by /u/rapidtonguelicking
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When will spaceprobes be able to use electricity as ther propulsion? Does this mean that they could in theory run for forever?

Posted: 09 Jul 2018 12:52 AM PDT

How does Caulerpa taxifolia square with the advantages of multicellularity?

Posted: 08 Jul 2018 11:18 AM PDT

When I ask my friend Google what's so hot about multicellularity, it says:

  • It allows organisms to get larger (not limited by diffusion).
  • It makes specialisation easier.
  • It's more robust because some cells can die without killing the organism.

Cool. Except: Enter Caulerpa taxifolia, the killer app killer alga. C. frickin' taxifolia don't care about any of the stuff I just said. C. taxifolia's unicellular as can be, but

Now if this was some kind of super-fragile trick that only works in some specific environment, okay, I'd let it slide. But this baby is wildly successful in a bunch of places, most of which are full of alga-eating things.

Someone's taking me for a ride here!

  1. If multicellularity is so good, what's C. taxifolia's trick to do better while being unicellular?
  2. Whatever that trick is, why can't I (and large complex organisms in general) copy it instead of being multicellular like a chump?

If y'all need me I'll be by the pond screaming at algae.

submitted by /u/JeremySmokedham
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What does trigger fruit ripening?

Posted: 09 Jul 2018 01:55 AM PDT

Does it occurs at a certain extent of growth? Can it be induced?

submitted by /u/frankven2ra
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Do humans know how reflections work from birth, or do they learn it?

Posted: 08 Jul 2018 10:01 AM PDT

A lot of other animals don't understand reflections. Do humans understand reflections from birth, or do we slowly learn how they work? If someone hadn't seen a reflection their whole life, and saw one when they were 50, would they understand it?

submitted by /u/polypeptide147
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Is gallium used in our everyday lives? Or is it just used to have fun with.

Posted: 09 Jul 2018 02:19 AM PDT

Im basically asking if humans use gallium to do anything scientific, does it have any special properties that other metals do not have (apart from the obvious lower melting temp)

submitted by /u/zacyut236
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How does real-time ray tracing work?

Posted: 09 Jul 2018 01:19 AM PDT

So I know the basics of real-time ray tracing. But I was wondering what effects this can have on rendered environments and if like motion blur, there are a multitude of ways this can be achieved. And besides that, can it be used for other purposes? Like moving the camera when it comes too close to an object.

submitted by /u/damylolface
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Will we ever get true color photos of nebulae? If not, why?

Posted: 09 Jul 2018 12:18 AM PDT

All the photos we have are composites and are black and white, but will there ever be a time when we have cameras that can actually show us what the real colors are, if any? If not, why?

submitted by /u/Myson91
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How many neurons does an average modern neural network have?

Posted: 08 Jul 2018 09:32 AM PDT

It's estimated that the human brain has about 83 billion neurons. I know that there is a huge difference between the biological brain and modern AI's on computers. Im also aware of that the number of neurons is not only decisive for the performance (beacause it plays a huge role how they are connected etc). But putting that aside, I'm interested in the amount of neurons to get a perspective of what modern computers are capable of processing in comparison to the human brain.

Also, on average to how many other neurons is every one of them connected? Again it's estimated that the neurons of the human brain have about 1000 connections.

Thank your for your answers!

submitted by /u/bistdunarrisch
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Does chaotic motion truly exist?

Posted: 08 Jul 2018 09:18 AM PDT

Hi all,

I've always found the concept of chaotic motion to be very puzzling, specifically the behavior of chaotic motion machines. I am a camp counselor at a summer camp, and our camp recently took a field trip to a science center in our city. I found the chaotic motion exhibit to be the most interesting as it featured one of these machines and allowed the user to witness its unusual and seemingly unpredictable behavior.

My question is this: Does chaotic motion truly exist? If the same amount of force is applied to get the machine in motion, will the behavior of the arms be different every time?

It seems to me like the phenomenon of chaotic motion results from the difficulty to recreate the exact conditions of the last spin of the machine, and this is what I tried to explain to the campers in my group (who were also interested in this exhibit).

Thanks so much!

submitted by /u/WetPretz
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Why are circuit boards green?

Posted: 08 Jul 2018 10:12 AM PDT

It seems so standard. I'm guessing it's some great, cheap, easily produced insulator to keep the wiring clean, but why is there no variety?

I would imagine that there's alternative methods to build these bad boys, but I've never seen one.

submitted by /u/i_made_reddit
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Is there a mathematical object which is a matrix but in 3 dimensions?

Posted: 08 Jul 2018 01:09 PM PDT

What I'm imagining is basically have a matrix on a piece of paper and then another matrix on another sheet of paper that lines up with the first sheet and so on.

If it exists, does it have any use in mathematics?

submitted by /u/CallMeAladdin
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Do negatively charged phospholipids affect the resting membrane potential of a cell?

Posted: 08 Jul 2018 11:46 AM PDT

Phospholipids are a major component of all cell membranes

Do phospholipids like phosphatidylserine and phosphatidylinositol affect the RMP, considering they're asymmetrically spread throughout the plasma membrane?

submitted by /u/diti123
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How does special relativity account for the magnetic field?

Posted: 08 Jul 2018 06:30 PM PDT

I have read that special relativity makes the magnetic field a consequence of the existence of an electric field. If this is right, could someone please explain how exactly this works?

Thanks!

submitted by /u/overweight_neutrino
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Sunday, July 8, 2018

Does egg yolk color tell us anything about the nutritious value of the egg?

Does egg yolk color tell us anything about the nutritious value of the egg?


Does egg yolk color tell us anything about the nutritious value of the egg?

Posted: 08 Jul 2018 04:18 AM PDT

Title.

submitted by /u/Mohcen
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Why do Flies behave the way they do around hanging light fittings?

Posted: 07 Jul 2018 01:57 PM PDT

With the hot weather, Flies inevitably end up coming through my open window and amassing around the light fitting in the centre of my living room, flying in a constant 4 or 5 point formation around the circumference of the light. Now I have seen this many times before but I have to ask... why do they do this? This light isn't on and doesn't even have bulbs in, but they are constantly drawn to it. Also, whats the little tussles they have with each other every few seconds or so? Are they fighting or is it some kind of reproductive thing?

submitted by /u/RiggzBoson
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How are lenses cleaned and maintained on large telescopes (e.g. The Hubble)?

Posted: 07 Jul 2018 07:17 PM PDT

Do birds feel wake turbulence from airplanes?

Posted: 07 Jul 2018 06:46 PM PDT

How does reproducibility happen in very expensive experiments?

Posted: 07 Jul 2018 06:11 PM PDT

I've been addicted to PBS Space Time and just got done with the "sterile neutrino" episode. The host mentions that several very large laboratory experiments disagree on the results.

That made me wonder: what happens when a claim is made that's the result of a very unique/expensive test result? I'm thinking along the lines of a particle accelerator or a test that's due to space probe data.

Wouldn't these not be reproducible under the same conditions? For instance, if a sensor was malfunctioning in a space probe - and some conclusion was made from the results, how would they be falsified?

Sorry for the long-winded question!

submitted by /u/profesh_2_death
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As objects fly higher in the sky, thebegin to cast larger shadows. At what point do their shadows start to get smaller?

Posted: 07 Jul 2018 03:25 PM PDT

Is there a sort of terminal point or height where the shadow will begin to get smaller?

submitted by /u/jay_gun
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How do Dual SIM-Dual Standby phones share the radio antenna between SIMs?

Posted: 07 Jul 2018 08:28 PM PDT

How do I scientifically measure quality of life in a country or city?

Posted: 08 Jul 2018 02:23 AM PDT

Are all discovered exo-planets in near-circular orbits like in our solar system? And are all exo-planets orbiting the same star all in the same orbital plane, like in our system?

Posted: 07 Jul 2018 04:24 PM PDT

What's the Curie temperature of a CoPtCr alloy hard drives are usually made of?

Posted: 07 Jul 2018 05:21 PM PDT

I was reading a bit about computer forensics and I thought that one way of effectively deleting all the data from a mechanical hard drive would be heating it up to the Curie point of the magnetic medium in the platters, so that magnetic domains get all messed up and what is left is just random bits. At what temperature would that Curie point be? Would it be the max between the Curie temperature of Cobalt, Platinum and Chromium? Or the min? Or maybe (as I think to be the most likely) the fact that we're talking about an alloy changes everything?

Thanks in advance to everyone who will spend their time answering this.

submitted by /u/JanitorsEvilEye
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How does Explosive Trace Detector work?

Posted: 08 Jul 2018 02:03 AM PDT

In the some aeroports, when people get searched, the searching team has a piece of fabric that they run on the searched person's electronics, clothes, hair and inside their bags, then put into this machine which supposedly shows whether traces of explosives exist or not.

How does this fabric keep the traces of explosives and not getting it mixed with anything else, and how is the machine able to check if those traces exist or not in matter of seconds? Does this machine do its job sufficiently? Or it's just another piece of time wasting procedures in the aeroport?

Edit: I am not sure if this is engineering or chemistry, but I'll put it chemistry since I think it is closer...

submitted by /u/Derura
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Why is there a convention of treating antiparticles as being 'time-reversed' on Feynman diagrams?

Posted: 07 Jul 2018 05:51 PM PDT

How does VPN (Virtual Private Network) work?

Posted: 07 Jul 2018 02:01 PM PDT

At school and at work, certain websites can be blocked, but I and many friends have used VPN to gain access to sites that are blocked and I have always wondered how VPN is able to do this and potentially what else it is useful for.

submitted by /u/NoRegrets15
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How did a seedless and underground vegetable like potato disperse and spread itself before human intervention?

Posted: 07 Jul 2018 08:33 PM PDT

I'm assuming other animals might have dug and eaten but still there's no seed to disperse. How and why did it even evolve in this way? Isn't it very disadvantageous for it?

submitted by /u/AshishBeck
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Do doctors take blood from organ donors when they die? If so, can they take the entire (approximate) 10 pints?

Posted: 07 Jul 2018 04:42 PM PDT

Gave blood earlier today and this seems like an enormous source of potential blood donaions.

submitted by /u/PndofSwedishcheeba
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Do the permanent magnets in coal power plants ever need to be replaced?

Posted: 07 Jul 2018 11:38 PM PDT

In other words, do the magnets in electrical generators ever need replacement?

submitted by /u/sleepystar96
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What are the ethics of human testing in things like the new HIV vaccine?

Posted: 07 Jul 2018 08:10 AM PDT

Source in case you aren't familiar with the specific study I'm asking about.

My question revolves around the ethics of human testing others, but mostly this case. How do you do human testing with something like HIV/AIDS, or anything without a cure. For example, if the vaccine doesn't work, or someone happens to have an unknown adverse reaction, and the person now has HIV.

submitted by /u/cardsoffate
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Why are prions from cows infective while those from pigs, poultry and fish are not?

Posted: 07 Jul 2018 08:07 AM PDT

In Jurassic park, the T Rex had movement-based vision. This has been disproven, but are there any animals, alive or extinct, which have this type of vision?

Posted: 07 Jul 2018 02:34 PM PDT