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Sunday, January 14, 2018

Ages 1 to 4 are very important for brain development but yet most people can't recall anything from that time period. Why don't we remember our earliest memories?

Ages 1 to 4 are very important for brain development but yet most people can't recall anything from that time period. Why don't we remember our earliest memories?


Ages 1 to 4 are very important for brain development but yet most people can't recall anything from that time period. Why don't we remember our earliest memories?

Posted: 14 Jan 2018 03:53 AM PST

I know the brain is rewiring a lot of neurological pathways to determine the most effective route, but what stops us from remembering our early years?

submitted by /u/Kattsu-Don
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How do gas mask filters for radioactive particles work? Why do they expire if not used?

Posted: 14 Jan 2018 04:03 AM PST

How many bytes of information can a single neuron store?

Posted: 13 Jan 2018 09:32 AM PST

Why is poo almost always brown, regardless of what we eat?

Posted: 13 Jan 2018 07:54 AM PST

Edit: judging by the notifications I'm getting to my phone, the moderators are doing a hell of a job keeping this thread clean. You have my appreciation, mods!

submitted by /u/Jimcube27
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If you're lost, is it better to look for your search party or wait?

Posted: 13 Jan 2018 08:37 AM PST

Assuming neither of you know the other's starting location or plan, what is the best strategy to be found as quickly as possible? Ignoring environmental conditions and survival necessities, speaking strictly mathematically, how can you maximize your chances of two points on a plan meeting? Do their relative speeds make a difference?

submitted by /u/Jackissocool
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What is the difference between electricity and magnetism?

Posted: 14 Jan 2018 05:05 AM PST

How does temperature-dependent sex determination work?

Posted: 13 Jan 2018 09:43 PM PST

I was reading this thread on r/science when I learned that the sex of many sea turtles/crocodiles/alligators is determined by the incubation temperature of its egg. How does this work, and how is (was) it a beneficial trait?

submitted by /u/JakeDanger-AWP
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Can a child be born with cancer?

Posted: 14 Jan 2018 03:55 AM PST

Is there anything stopping a baby getting cancer in the womb?

submitted by /u/JustAlfieInnit
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How does the suns gravitational pull affect earths moon? Wouldn't the sun just give the moon its own rotation?

Posted: 13 Jan 2018 09:22 PM PST

If the speed of light is the fastest possible speed something can move, and heat is just the speed at which particles are moving, does that mean there's a maximum temperature that nothing can exceed?

Posted: 13 Jan 2018 07:41 PM PST

Why all rays of light haven't a velocity of c?

Posted: 14 Jan 2018 07:02 AM PST

Here is a picture of Lorentz transformations :

https://upload.wikimedia.org/wikipedia/commons/8/8d/Time-dilation-002-mod.svg.png

If we admit the frame on the left is R' and the frame on the right is R:

The blue ray in R has a velocity of c.

The path of the blue ray is smaller in R' than in R. It is why we add time dilation and length contractions. So, Lorentz find that the blue ray in R' has a velocity of c also.

If we add a red ray in R' with a velocity of c.

Why the red ray in R has a velocity smaller than c ?

submitted by /u/MorePhi
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When talking about the electromagnetic field and the different frequencies, what exactly is the medium that is vibrating?

Posted: 13 Jan 2018 03:14 PM PST

As I understand it, the different in visible light and radio waves is the difference in frequencies or vibrational speeds. What is vibrating? Since these things can travel through a vacuum, I assume that it isn't matter, right?

submitted by /u/SelfandMind
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Why do the stomata of a plant open when there are too many mineral ions?

Posted: 14 Jan 2018 03:19 AM PST

What is a Spin?

Posted: 13 Jan 2018 07:36 PM PST

I've been watching phsyics related stuff for a while now since I wanna go into that field and I hear it all the time in Quatum Mechanics, yet the closest thing I've gotten to a definition may have been something like polarity almost like how a magnet works ? Could be I interpreted it wrong. The fact they say spin does and doesn't exists confuses me too!

submitted by /u/jesusdasir
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What is baking soda? What is baking powder? What is the difference between the two.

Posted: 14 Jan 2018 02:59 AM PST

I would like to know more about baking soda and powder. What are they made of and how do they work?

submitted by /u/gafgalron
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What makes the dye in a dye pack unremovable from skin?

Posted: 13 Jan 2018 08:40 PM PST

What happens to the crystalline structure of radioactive elements when an atom decays?

Posted: 13 Jan 2018 11:53 AM PST

For instance uranium, how does the surrounding atoms adapt to the changes in volume and electronic overlap when a particular atom disintegrates to another element? Does a slab of uranium become brittle over time because of it?

submitted by /u/novalaise
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How do reflective surfaces (like a mirror) differ physically from non-reflective surfaces? What makes them reflect light?

Posted: 13 Jan 2018 05:39 PM PST

If magnetic domains attract each other, then why do unmagnetized metals become demagnetized when removed from the presence of a magnet?

Posted: 13 Jan 2018 09:54 AM PST

If you had 100 magnets all stuck together in the form of a cube, to visualize magnetic domains, the theoretical point of lowest energy would be one entire row facing south, one row facing north and so on. That way each magnet will feel nothing but attraction. In this state the 'magnet' would be considered demagnetized because of the alternating rows.

To magnetize it, each row would have to face the same way. This is not the overall lowest position of energy for each domain, but each domain is attracted top and bottom as well as repelled by each other side to side. And since each domain must flip individually (an entire row can't flip on its axis) there seems to be no reason for it to become demagnetized once magnetized. The attraction acting on each domain would, at least, cancel out the repulsive force working to flip them. So why do magnetic domains flip at all?

submitted by /u/NarrowPPHole
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If lobsters have no age limit, how do they control population numbers?

Posted: 14 Jan 2018 03:37 AM PST

I've been informed that lobsters are one of few species on the planet that do not age. If that is true, how are lobster population numbers regulated in the wild? I imagine it is a mixture of predators, disease, and possibly selective breeding windows, but I thought I'd ask the question here to see if there is someone more informed who could tell me more about it. Thanks!

submitted by /u/IWJF
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How do scientists find the melting point of some solids without melting their equipment?

Posted: 13 Jan 2018 10:58 AM PST

Can a quantum transformation change a quantum state completely?

Posted: 13 Jan 2018 03:37 PM PST

I'll explain on example of photon passing through the polarization filters. The photon that passes through diagonal and vertical polarization will be filtered out, however if you introduce a 45 degree polarization, some will pass through. If you think about it, it means that after first one, all photons a diagonally polarized, but after next two they are horizontally polarized.

Ok, no let's consider a series of filters which are slightly turn in relation to each other, effectively they shouldn't filter much, while they should change diagonal polarization to horizontal.

My question is can you create a transformation of a quantum state, that from state |1>+|0> creates a state |0>+|1>. Add entanglement here, meaning from state |01>+|10> produces a state |11>+|00>?

To visualize it, can you transform a state of two entangled particles two completely different ones? I.e. from polarized vertically to polarized diagonally, even if you never measure them in between?

Of course there is a follow up question if it happens so, what happens if you measure one entangled particle at random time, can you still apply such a transformation on a random time on a second particle?

submitted by /u/Heappl
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Saturday, January 13, 2018

If gravity causes time dilation, wouldn't deep gravity wells create their own red-shift? How do astronomers distinguish close massive objects from distant objects?

If gravity causes time dilation, wouldn't deep gravity wells create their own red-shift? How do astronomers distinguish close massive objects from distant objects?


If gravity causes time dilation, wouldn't deep gravity wells create their own red-shift? How do astronomers distinguish close massive objects from distant objects?

Posted: 12 Jan 2018 07:42 PM PST

Do particles move in a solid? Do they oscillate or vibrate?

Posted: 13 Jan 2018 06:03 AM PST

I've heard about movement of particles in a gas or a liquid, but what about a solid?

submitted by /u/SomeoneImportant69
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If skin cells are one of the fastest replicating cells, how come moles, and birth marks don’t disappear over time?

Posted: 12 Jan 2018 11:53 AM PST

Same goes for warts and scars.

submitted by /u/C0mGussler
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Do gravitational waves have frequencies?

Posted: 12 Jan 2018 05:56 PM PST

I feel like the obvious answer is they do, but I don't know the answer. And if so, what determines their frequencies? Mass? How noticeable are these frequencies, and what would the frequency of a gravitational wave from the sun be compared to the black hole collision that LIGO observed?

submitted by /u/JawaSlayer501
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What determines how many energy levels an electron can be excited to in an atom?

Posted: 13 Jan 2018 06:15 AM PST

So electrons exist in a natural or ground state in an atom. When a photon hits a valence electron, the photon is absorbed and the electron is either raised to a higher energy level equal to the amount of energy of the photon or ejected from the atom.

What determines how many energy levels an electron can be raised to though before it is ejected? Will a H atom only have 7 energy levels and then any more energy it would be ejected from the atom while a Na atom may have 15 energy levels before being ejected?

submitted by /u/IbraheemLinkin
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Can you make blackholes from electromagnetism? If so, why are there so many made from gravity since electromagnetism is so much stronger?

Posted: 12 Jan 2018 03:16 PM PST

Why are the coldest months of the year (typically Jan/feb) not also the month with the shortest days (dec)?

Posted: 12 Jan 2018 02:01 PM PST

Regarding thermionic emission... if you heat up any metal of any kind hot enough, does it always release electrons in to the air? for example if you heat a needle with a flame

Posted: 12 Jan 2018 05:10 PM PST

ie whether in a vacuum or not

submitted by /u/tupeloms
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If a ship could travel at 99.9% of C, how long/far could it travel before returning to our galaxy would be impossible?

Posted: 12 Jan 2018 11:22 AM PST

If a ship could travel at 99.9% of C, how long/far could we travel before returning to our galaxy would be impossible due to it having moved out of the ship's observable universe? Would the answer differ based on direction the ship travels?

submitted by /u/Starbokh
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Is the electrical component always in phase with the magnetic component in an EM wave?

Posted: 12 Jan 2018 01:09 PM PST

In an EM wave is the magnetic component always in phase with the electrical? Or can they be shifted 90°(not spacially but in phase) for example so that the electrical peaks when the magnetic is 0 and vice versa.

And if for example its around the wavelength of a few meters, would the phase shift( if possible) impact how easily we can convert this signal to current in a wire with an antenna?

submitted by /u/ternal38
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What would happen if you pointed a laser beam tangent to the event horizon of a black hole?

Posted: 12 Jan 2018 12:55 PM PST

I know that past the event horizon, light couldn't escape a black hole's gravity. By that logic, anything before the event horizon should allow light to escape and move out freely into space. But what happens if you theoretically shine a light (or fire a single photon) perfectly tangent to the event horizon?

submitted by /u/mhmc20
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When will the next conjunction of Saturn and the Sun take place?

Posted: 12 Jan 2018 12:12 PM PST

Does anyone know when Saturn and the Sun will be in conjunction? That is: I'm interested in knowing when the Sun will be exactly between Earth and Saturn, making the gas giant essentially invisible from Earth. Also, I'd like to know for how long this would last.

Thanks in advance!

submitted by /u/Conscious_Mollusc
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Is there a ratio between the weight of a submersible vehicle and the amount air needed inside to keep it afloat at different depths? Could I theoretically make a sub as large as I want as long as it could hold air?

Posted: 12 Jan 2018 03:14 PM PST

Does the holographic principle literally imply that if I give you all the information about the walls in my room, you would be able to deduce what's inside my room?

Posted: 12 Jan 2018 06:26 AM PST

Can other sources of light be concentrated through a magnifying glass to start a fire? Like the light from a flashlight, or from a full moon?

Posted: 12 Jan 2018 08:11 AM PST

How does escape velocity work?!?

Posted: 12 Jan 2018 01:40 PM PST

Escape velocity does not make any sense to me! In theory if an object leaves the surface of a mass/planet in an otherwise empty universe, without any extra purpolsion after, won't it eventually come back? Gravity is an acceleration which keeps shaving off the kinetic energy of the object, so no matter how far it goes at some point the velocity will turn around, right? The kinetic energy of the object can be depleted but the potential energy induced from gravity cant so how do they negate?

And what does someone mean by "escaping" a gravitational field? No matter how far apart something if from a mass it will never escape its gravitational pull!

My only theory to my conundrum is this. I know the "escape velocity" is calculated by using the potential energy calculated from the mass. Which means as your measurement of the mass becomes infinitely more precise the escape velocity becomes infinite, I think?

This is my first post on reddit (so srry if it's confusing and long) as no matter where I looked I couldn't find anything that could answer my doubts.

Thx in advance.

submitted by /u/DurusFlurgus
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How tightly is DNA coiled?

Posted: 12 Jan 2018 09:01 AM PST

Our students were making models of DNA and we began wondering how quickly you actually see the spiral shape. How many pairs does it take for it to go completely around?

submitted by /u/daniel14vt
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What decides the capacity of a battery?

Posted: 12 Jan 2018 09:51 AM PST

I was doing my daily pondering, and came across this question, which I'm quite interested to know the answer to.

submitted by /u/lugii
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Different colors on a thin film are said to be caused by interference. Why do we not say that thin films simply reflects certain wavelengths?

Posted: 12 Jan 2018 07:31 AM PST

Based on equations from interference by thin films we know that wavelengths that are present on top side are absent at the bottom. This result can be achieved by simply saying that thin films reflect certain wavelengths and transmit others.

submitted by /u/TheMamoru
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Friday, January 12, 2018

Why can completely paralyzed people often blink voluntarily?

Why can completely paralyzed people often blink voluntarily?


Why can completely paralyzed people often blink voluntarily?

Posted: 12 Jan 2018 04:01 AM PST

If a phone is plugged in to a charger and the battery is full, does the phone use the battery or the charger as a power source?

Posted: 12 Jan 2018 04:50 AM PST

Is the battery simultaneously being charged and discharged or is it bypassed when plugged in to a charger? Does using the phone while plugged in extend overall battery life?

submitted by /u/AtheistKiwi
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ELIMathematicianNotPhysicist: Quantum Bayesianism. What is it, and how is it different from all the other ways to look at QM?

Posted: 12 Jan 2018 05:35 AM PST

Does the finding of baryonic matter between galaxies allow for a possible equilibrium state of the universe (as opposed to big bang vs big crunch)?

Posted: 11 Jan 2018 11:48 PM PST

I read about relatively recent findings that the space between galaxies may actually hold a lot of our universe's baryonic matter. I also vaguely understand that the left-hand side of the Friedman equation is cited as reasoning behind the theory that the universe is infinitely expanding, with the amount of matter available being insufficient to stop it.

If there really is baryonic matter in-between galaxies, is its presence, and subsequent mass, enough to allow the possibility of an eventually static universe?

submitted by /u/ReddneckwithaD
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What does a surgeon do to reform bone after a surgery?

Posted: 11 Jan 2018 05:59 PM PST

I'm thinking of brain surgery where a surgeon will have to actually cut through the skull to work with the brain. After the surgery is complete how to they put the skull back together?

submitted by /u/Hansinator13
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What is responsible for the evolution of a magnetic field in the superconductor during The Meissner Effect experiment?

Posted: 12 Jan 2018 02:54 AM PST

Are dogs gray wolves?

Posted: 12 Jan 2018 02:20 AM PST

According to wikipedia, domestic dog is synonymous with Canis lupus familiaris, a subspecies of Canis lupus which is synonymous with gray wolf, meaning all domestic dogs are members of the species Canis lupus meaning they are gray wolves.

This sounds pretty strange to me and probably any layman, but the lead-in to the gray wolf article just makes it sound like they're talking about what I would know as wolves, and the "taxonomy and evolution" subsection - though I only skimmed it - treats dogs and gray wolves as separate categories at several points, rather than one as a subcategory of the other.

(The gray wolf article doesn't specify 'domestic' but it hyperlinks to the article 'Dog' which appears to be exclusively about the domestic dog.)

There's also a "Comparison with wolves" section, which says "there are a number of diagnostic features to distinguish the gray wolves from domestic dogs".

What's going on here? Is wikipedia just being sloppy or is the terminology sloppily applied in the literature too, or am I just misunderstanding something?

https://en.wikipedia.org/wiki/Dog

https://en.wikipedia.org/wiki/Gray_wolf

submitted by /u/Bl_rp
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At what time of sleep do we really dream?

Posted: 12 Jan 2018 12:16 AM PST

Googling pretty much tries to tell me that dreams happen during "REM phase" which is "stage five" after falling asleep, which supposedly is supposed to happen only after being asleep for quite some time.

Now I dont know if this is just me, but if I drowze off for just 10 seconds to few minutes, I almost always wake up with a clear memory of a vivid dream. And I wouldnt classify these just as hallucinations. I could be sitting in classroom and close my eyes for just a few seconds, and suddently im an admiral commanding a fleet in the pacific. Then I wake up for 20 seconds, and fall asleep back to a compleatly different dream. If im not sleepy, nothing like this ever happens.

And if I take a 10minute nap during the day, I always wake up from a dream.

submitted by /u/empire314
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Shouldn't most stars have multiple planets form around them?

Posted: 12 Jan 2018 06:37 AM PST

Due to how we know stars are formed, shouldn't the vast majority of dust rings eventually become planets as particles combine and eventually clear their ellipses? I know that we can only see ones that have the right profile to allow us to see the planets transit across the star or that have planets large enough to currently see. But how common would a planet-less "system" even be given what we know?

I asked this previously but received no reply. This will be my final attempt to learn the answer here. Last time was under an astronomy flair, here goes a planetary science flair.

submitted by /u/lightknight7777
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From the first Hydrogen-Hydrogen fusion event to reaching thermonuclear stability, how long does it take a proto-star to 'turn on' and become a real star?

Posted: 11 Jan 2018 12:20 PM PST

What physical properties make Iron, Cobalt and Nickel ferromagnetic?

Posted: 11 Jan 2018 10:00 PM PST

I'm currently studying magnetism and I was curious about the things that make a material "more magnetic" than others. For example, Gold doesn't let magnetic fields through as well as Aluminum (one is diamagnetic and the other is paramagnetic if I'm not mistaken).

What properties establish this differences?

submitted by /u/Delfador999
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Can someone explain the equation on this conditioner?

Posted: 11 Jan 2018 06:00 PM PST

Found at my local hair salon

It looks like:

E = -mu(vector) • B(vector)

I can't figure out what this is but desperately want to understand the humor of the conditioner bottle.

Any ideas?

submitted by /u/CyborgScrivener
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Why does decoherence produce probabilistic outcomes?

Posted: 11 Jan 2018 11:56 PM PST

I am reading the book The Fabric of The Cosmos, and Brian Greene explains that when the wavefunctions of a large number of particles interact with a small particle, the wavefunction of the small particle transforms into a sharp spike. What I don't understand is that, since Schrödinger's equation is totally deterministic, shouldn't the result be deterministic as well? Why would we have probabilities of finding the spikes in different locations? I think he must have missed some important details in the book. Thank you.

submitted by /u/MysteriousEntropy
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How do antennas work?

Posted: 11 Jan 2018 05:00 PM PST

How does it enhance reception by extending from a device only a few inches? Is it reception they are enhancing?

submitted by /u/420Savage4402
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What is the difference between sleeping and just laying down to rest? How do the 2 differ when it comes to your health?

Posted: 11 Jan 2018 05:34 PM PST

How does fatigue affect eyesight?

Posted: 11 Jan 2018 04:34 PM PST

Some days when I really feel tired I also notice that I can barely see clearly, and I'm forced to wear my glasses. But other days when I get a good night's sleep and I feel awake and energetic the next day, I have no problem seeing clearly and don't feel like I'm straining or squinting my eyes. How is this so?

submitted by /u/SkidTrac
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How do space rockets guide themselves on the correct path during launch if they only only have boosters?

Posted: 11 Jan 2018 02:33 PM PST

Are there 90 degree side rockets that can course correct to preven the rocket from going crazy like a balloon letting out air?

submitted by /u/Xacto01
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Does the danger of nuclear waste increase with the addition of more nuclear waste?

Posted: 11 Jan 2018 08:58 PM PST

For example, if you have some waste (spent fuel rods or whatever) from a nuclear reactor and they have a danger zone of say 1 mile. If you keep on piling up more rods, does the danger zone increase?

submitted by /u/Angrybakersf
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How do the organs of people who are paralyzed from a spinal injury continue to function?

Posted: 11 Jan 2018 01:37 PM PST

I recently watched a documentary about a man who was paralyzed from the neck down due to a spinal injury. His muscles were obviously paralyzed but I couldn't help but wonder how his heart, his lungs, and all his other internal organs continued to function with a spinal injury?

submitted by /u/Jamblasticus
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Why does James Webb Space Telescope needs to be in L2 lagrangian point? What are the benefits other we don’t worry about losing orbit...

Posted: 11 Jan 2018 07:25 PM PST

Edit - other than we don't need to worry about losing orbit time to time ..

submitted by /u/Rbhadaur
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What is the process by which satellites make electricity from plutonium?

Posted: 11 Jan 2018 10:43 AM PST

Do flamingoes always stand on the same leg?

Posted: 11 Jan 2018 12:43 PM PST

I can't find research on this besides information on why they stand on one leg.

submitted by /u/simmerandstir
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