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Tuesday, June 7, 2016

If atoms are 99% 'empty space', how big would the universe be if we compressed every atom down to it's most space efficient arrangement, essentially leaving no space between particles?

If atoms are 99% 'empty space', how big would the universe be if we compressed every atom down to it's most space efficient arrangement, essentially leaving no space between particles?


If atoms are 99% 'empty space', how big would the universe be if we compressed every atom down to it's most space efficient arrangement, essentially leaving no space between particles?

Posted: 06 Jun 2016 04:00 PM PDT

Or our observable universe, whatever is easy to speculate on... My thoughts were that perhaps the universe would become small enough to resemble what was present before the big bang, and the expansion between everything has just taken a very slow and long time (the rate at which our universe is expanding now?) and appears to have "exploded", hence the Big Bang...

submitted by /u/Hello-Universe
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We don't feel the earth spinning because it is constant. Yet it is fastest at the equator and gets slower as you move away from it. My question is how come no one ever notices the increase or decrease when traveling towards the equator or away from the equator?

Posted: 06 Jun 2016 07:46 PM PDT

Why do some objects emit a 'pitchless' sound when hit, and others a 'tuned' sound?

Posted: 06 Jun 2016 12:25 PM PDT

If you hit a table, it makes a noise, but not one that you could apply a conventional pitch (like G#) to. If you hit a xylophone it makes a very clear, discernable tone that you can easily assign a note to.

Why is this the case?

submitted by /u/silverben10
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Are organisms that regrow appendages like flatworms and starfish at risk of diseases like cancer?

Posted: 06 Jun 2016 08:40 AM PDT

On a rotating object, such as a ceiling fan, does the outermost tip of the fan blade move at a faster velocity than the point that's closest to the center since it has a larger circumference to travel?

Posted: 07 Jun 2016 04:48 AM PDT

For a given volume, are magnets with a larger surface area stronger than ones with a smaller surface area (in the direction of magnetization)?

Posted: 06 Jun 2016 08:29 PM PDT

For ex take 2 cylindrical magnets that are axially magnetized, would the one that has the larger flat surfaces but shorter cylindrical length be stronger/weaker/same as the one w/ smaller surfaces but longer cylindrical length? Thanks!

submitted by /u/clitbeastwood
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Besides nitrogen fixing bacteria what other non-plants use atmospheric nitrogen?

Posted: 06 Jun 2016 07:07 PM PDT

I've been trying to understand the nitrogen cycle, particularly as it relates to organic gardening. Compost, manure, various meals, etc get added to the soil to increase the levels of ammonia, urea and other nitrates in the soil.

It is my understanding that most of that nitrogen came from directly or indirectly eating plants. Do animals besides bacteria perform any nitrogen fixing? Or is the dissolved nitrogen gas in the body just a side effect of living on earth with no biological purpose in our blood?

submitted by /u/Snewzie
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Mathematicians/cryptographers, what is the significance of the three-number security code on a credit card? Wouldn't it be just as effective to add 3 more numbers onto the credit card number?

Posted: 06 Jun 2016 07:29 PM PDT

Would the gravitational waves from the Shoemaker–Levy 9 comet's collision with Jupiter have been large enough to register?

Posted: 06 Jun 2016 07:48 PM PDT

Why are random access speeds of flash memory different from their sequential access speeds?

Posted: 06 Jun 2016 08:57 AM PDT

I understand that on rotational disks, sequential reads and writes are faster than random ones because the head is already in place to read sector B after it reads sector A, and moving over to sector Z takes time. But a flash device has no moving parts. Why is reading page A followed by page B faster than reading page A followed by page Z?

submitted by /u/notverycreative1
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Is it possible, or even desirable, to make wells to recharge aquifers, like this sinkhole near San Antonio?

Posted: 06 Jun 2016 11:00 PM PDT

Here's a video of water gushing down a sinkhole into the Edwards Aquifer west of San Antonio, TX. Pretty often we're warned that aquifers on the plains, like the Edwards and Ogallala, are on the verge of being emptied, but meanwhile when it rains, most of the runoff goes into the ocean.

What would be the negatives of making artificial means to recharge aquifers during rainy spells, so you'd have water to use during droughts?

submitted by /u/mutatron
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Are magnetic metals still magnetic when molten?

Posted: 06 Jun 2016 10:38 AM PDT

i.e. if I melt down a bunch of steel, will the molten steel still be magnetic?

submitted by /u/Yazman
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What's the chance of having drunk the same water molecule twice?

Posted: 05 Jun 2016 06:27 AM PDT

[physics] can exist a spherical configuration of matter, in which for every radius the mean density of the sphere be equall to the density needed to the creation of a black hole?

Posted: 07 Jun 2016 04:20 AM PDT

Citing directly the Wikipedia article https://en.m.wikipedia.org/wiki/Schwarzschild_radius

"An object of any density can be large enough to fall within its own Schwarzschild radius,"

So, is possible to make a configuration that have two distinct radius of schwarzschild? A configuration that have infinite?

What would happen in this situation?

Even this: can I throw matter around a black hole in a way that another bigger black hole be created around the first?

Thanks in regards!

submitted by /u/daniel_h_r
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Why do glasses and ceramics dry quickly, but plastic tupperware stays wet?

Posted: 06 Jun 2016 07:24 AM PDT

Are there any effective means to slow memory loss in the elderly?

Posted: 06 Jun 2016 03:41 PM PDT

My father is 70 years old and beginning to have noticably worse memory. His mother (early 90's) has pretty severe dementia, but we don't know if my father is getting the early symptoms of dementia or simply age-related memory loss.

In either case, the internet is full of "memory enhancement" gimmicks and pills, but is there anything that is actually effective that I can recommend to him?

submitted by /u/entirelyalive
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Can a neutron star become a black hole?

Posted: 06 Jun 2016 07:02 AM PDT

Why do solar panels use semiconductors such as silicon? Why not just regular conductors?

Posted: 06 Jun 2016 07:49 PM PDT

Would it have anything to do with being able to dope the material as is done with silicon?

submitted by /u/PrimalBidoof
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Are earthquake P-Waves audible?

Posted: 06 Jun 2016 10:10 AM PDT

I had a pretty cool experience this weekend that has started a bit of a debate between a friend and myself. Hopefully you all can resolve it!

Saturday morning, I was camping in the Santa cruz mountains above the Silicon Valley in california. At about 6AM I was in my tent, in the middle of the forest, with my head on my camp (air) pillow when I heard a distinct "pop" followed by what can only be described as a low frequency "twang" that smoothly shifted downward in frequency. About a second to a second and a half later, the ground moved. The sound level for the twang was actually fairly high. Those of us still in our sleeping bags on the ground heard it very distinctly, but several in our group were standing up and heard it as well...though they described it as being substantially fainter. If we'd been anywhere other than a dead silent forest at 6AM, we probably wouldn't have heard it at all.

As it turned out, we were camped about a kilometer from the epicenter of this earthquake: http://earthquake.usgs.gov/earthquakes/eventpage/nc72645676#general, http://scedc.caltech.edu/recent/Quakes/nc72645676.html. It was a little one, but sitting at ground zero of a 3.4 definitely wakes you up!

This has touched off a bit of a debate between one of my fellow campers and myself. He believes that the "pop" and "twang" were higher frequency sound waves generated by the original fracture and release of tension, propagated through the ground and into the air. I argued that it was more likely that the early P-Waves from the quake simply created enough movement to generate sound (by friction) in the soil and rock immediately around us, and that the noise wasn't from the rock fracture itself. He countered with a couple of links claiming that P-Waves occur at frequencies far below the range of human hearing, and that they couldn't have caused the sound.

So, the question: What did we hear? Were they P-Waves? What can make the ground "twang" before it moves? Do I owe him a beer?

submitted by /u/codefyre
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Do animals get sickle cell anemia?

Posted: 06 Jun 2016 06:49 PM PDT

I read before that there was genetic testing done on rats with sickle cell anemia but I'm unsure if that was natural or not. And if animals do get sickle cell, what animals are afflicted with the disease?

submitted by /u/Prince_Silk
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Why doesn't the temperature of a gas dissapate as quickly as its pressure in an open system?

Posted: 06 Jun 2016 08:32 AM PDT

If pressure and temperature of a gas are directly proportional given closed system, why doesn't heat escape an open system as quickly as pressure?

Example, an oven will remain hot for several minutes even if you open the doors. If the air in the oven was under pressure, it would immediately equalize the second you opened the door. Well, wouldn't the pressure of the oven be high if the temperature was high? And so shouldn't the heat in the oven quickly dissipate as soon as you open the door?

submitted by /u/MpMerv
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Why does spectral violet seems to have a red hue?

Posted: 06 Jun 2016 02:13 PM PDT

I've seen several threads here discussing this already, but none seems to have a conclusion.

Looking at this article: http://www.huevaluechroma.com/032.php , considering the spectral absorbency of the cones, there's no much sense in thinking that the red cone gets excited from spectral violet, unlike what the CIEE colour matching diagram looks like https://upload.wikimedia.org/wikipedia/commons/thumb/8/8f/CIE_1931_XYZ_Color_Matching_Functions.svg/325px-CIE_1931_XYZ_Color_Matching_Functions.svg.png .

The colour zone theory on that same article shows a explanation for that, but i didn't get why does r/g get's positive in the violet area. y/b getting negative makes total sense, once the M and L cones are getting less and less activated while the S gets more. But why does r/g get positive, if there's no more light being absorbed by the L cones than by the M cones on that area?

Thanks!

(Note: This is a repost, the first post apparently got a bug, it was shown as normal for me, but only for me. It was shown as removed for others users and non-users, so i removed it.)

submitted by /u/guferr
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Monday, June 6, 2016

AskScience AMA Series: I am Dr. Laura Kloepper, a biologist who studies the emergence and echolocation dynamics of large bat cave colonies. This summer I am traveling and camping with two female students as we record bats across the Southwest. Ask Me Anything!

AskScience AMA Series: I am Dr. Laura Kloepper, a biologist who studies the emergence and echolocation dynamics of large bat cave colonies. This summer I am traveling and camping with two female students as we record bats across the Southwest. Ask Me Anything!


AskScience AMA Series: I am Dr. Laura Kloepper, a biologist who studies the emergence and echolocation dynamics of large bat cave colonies. This summer I am traveling and camping with two female students as we record bats across the Southwest. Ask Me Anything!

Posted: 06 Jun 2016 05:00 AM PDT

Hi Reddit! I am Dr. Laura Kloepper, an Assistant Professor of Biology at Saint Mary's College in Notre Dame, Indiana. My research involves using audio, video, and thermal imagery to understand the emergence, flight, and echolocation dynamics of large (1 million +) colonies of Mexican Free-tailed bats. These bats leave the cave at densities of up to 1,000 bats per second, flying at speeds of 25 mph, beating their wings ten times per second, and rarely run into each other. Their primary mode of navigation is using echolocation, or making a loud sound and using the information in the echoes to create a visual representation of their surroundings. Everything we know about biology, mathematics and physics says that they should not be able to successfully echolocate in these large groups. My main research involves trying to understand how they are able to successfully navigate via echolocation without interfering with one another, and these findings have technological implications to improve man-made sonar. I am also interested in flight dynamics in large groups, factors that control the emergence timing, and unique characteristics of bat guano.

This summer I am traveling with two female undergraduate students and my trusty field dog as we visit 8 caves across the Southwest to tackle multiple research projects. We will be doing a lot of camping, consuming a lot of canned food, and putting close to 7,000 miles on our rental SUV. We will be documenting our journey on our blog, www.smcbellebats.wordpress.com, or on our Twitter and Instagram (@smcbellebats).

I will be here from 12:00pm EDT to 2:00pm EDT to answer your questions...AMA!

submitted by /u/AskScienceModerator
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[Electrical Engineering] If electric fan knobs are made to resist a set amount of electricity, then is the amount of elecricity consumed in the fan equal regardless of the amount of resistance in the knob?

Posted: 06 Jun 2016 05:00 AM PDT

In advance, I apologize for the horribly butchered question. I wasn't quite listening during workshop class.

submitted by /u/NoviKey
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A small amount of sodium hydroxide is added to sodium hypochlorite to stabilize the bleach, what does this mean and how does this work?

Posted: 06 Jun 2016 06:42 AM PDT

Is light slowed down by traveling through the Higgs field?

Posted: 05 Jun 2016 08:05 PM PDT

Is there a way to tell the difference between two atoms of the same element?

Posted: 05 Jun 2016 07:53 PM PDT

Is there a way that a scientist could look at an atom, and then be able to tell that atom from any other atom of the same element? If so how? If not, why not?

submitted by /u/Nemothewhale87
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The Griffith Park Observatory pendulum knocks over pegs as the Earth rotates beneath it - how come this works if the pendulum is not on the Earth's axis of rotation?

Posted: 05 Jun 2016 08:25 PM PDT

How does the sense of *me* generated in our head. Which exactly is the brain part which generates it?

Posted: 05 Jun 2016 08:08 PM PDT

Also, is self awareness related to being me? Do we have this me feeling when in coma?

submitted by /u/hegman12
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What's the difference between diesel that a car, train and submarine uses?

Posted: 06 Jun 2016 04:51 AM PDT

I heard that diesel that a train uses is dark and more viscous than diesel a car uses, does that mean it has a longer chain length? If so does the term "diesel" just encompass fuels that are longer in chain length than petrol and kerosene?

submitted by /u/iYammmzTV
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Is there a way to model any given atoms electron structure in 3d space?

Posted: 05 Jun 2016 05:52 PM PDT

For example Lithium has an electron structure of 1s2 2s1 right. Well does the 2s1 part go around the 1s2 part? I mean what does the electron structure of Nitrogen look like in 3d space? Does the 3s orbital go around the 2p orbital? How do all of those weird shapes fit together in 3d space?

submitted by /u/heezeydeezay
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Is all arithmetic derived from addition?

Posted: 05 Jun 2016 10:35 AM PDT

There are 4 major operations that are in mathematical arithmetic being addition, subtraction, multiplication, and division.

Addition: 4 + 5 = 9

Subtraction: 6 - 3 = 3 -------- in addition ------> 6 + (-3) = 3

Multiplication: 2 * 3 = 6 -------- in addition ------> 2 + 2 + 2 = 6

Division: 10 / 2 = 5 -------- in addition ------> 10 + (-2) + (-2) + (-2) + (-2) + (-2) = 0 and there are five 2's meaning the answer is 5

Does this mean that what happens in all of mathematics can be broken into a basis of addition of different values, or is there some operation that negates this?

submitted by /u/pixlbreaker
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Could hawking radiation reduce a black hole in such a way that something that was once inside could eventually escape?

Posted: 05 Jun 2016 06:36 PM PDT

I know that once inside the event horizon, spacetime is curved such that every direction leads towards the singularity. But I assume (perhaps incorrectly), that it is kind of like a limit in math... that you can never find a trajectory out, but you could find one that was closer and closer to perpendicular to the singularity to the point where, theoretically, it would take nearly forever to fall in. So if a photon were on such a trajectory, and the black hole slowly shrinks due to hawking radiation, could the photon eventually get out? Or would the evaporation simply change the possible trajectories such that the photon still could never escape?

submitted by /u/ibn4n
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Why is oil hydrophobic?

Posted: 05 Jun 2016 07:39 PM PDT

How does Metabolism impact drug tolerances and dosages?

Posted: 05 Jun 2016 10:18 PM PDT

I'm asking because it's something I deal with, and my inquisitiveness wants to know now. I want to be clear, I am not looking for personal advice or information.

My question is essentially this, if you have a high metabolism does this mean your body metabolises a prescription medicament quicker thereby having a higher tolerance because less of it is entering into your body to do it's job?

I'll just add context, and yes it's a personal example, but I just want to understand if my metabolism did have an impact how would it? I have taken many prescription drugs, and it was hypothesised by my doctor that my metabolism must be fast because we seem to have to go onto high dosages for there to be an effect. Thyroid has been tested and it's quite normal.

But just what I find interesting is consuming a mug of coffee can feel like a full meal to me, and I don't feel the need for lunch. Im told this is a sign of a slow metabolism. So that leads to does metabolism react different to different substances?

Sorry for the personal information, but these are examples that people with the expertise can help provide a plausible explanation.

submitted by /u/Gmreyes
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[PHYSICS] What is a second?

Posted: 05 Jun 2016 02:59 PM PDT

I know there is a standard item for a meter and a gram but is there some sort of universal measurement of one second? Could you explain one second to an alien or is it a human construct?

submitted by /u/Benhamm22
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Can you re-magnetize a magnet by running a current through it?

Posted: 05 Jun 2016 08:55 PM PDT

I know the traditional way to remagnetize a magnet would be to wrap a wire around it and then run a current thought the wire, but what would happen if you applied a voltage directly across the magnet? Would it remagnetize?

submitted by /u/mispulledtypo381_
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Why does the value of some goods decline over time, while other goods get more valuable as time passes (like vintage cars)?

Posted: 05 Jun 2016 08:21 PM PDT

I can't find a ton of information on the Internet about this, but one thing that could contribute to higher prices for cars is that most vintage cars are auctioned, so inflated prices are more likely.

submitted by /u/waddellj
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Can you slow down electricity going through a wire?

Posted: 05 Jun 2016 07:31 PM PDT

I'm trying to understand how frequencies work. From what I'm reading, frequencies are based on the length of the transmitting antenna. In water, making a wave could be done by moving a rock up and down in water at a certain speed, for example along a 4 foot stick. Making a faster wave (or higher frequency) would be doing it with a smaller stick, or lower frequency with a longer stick.

But you could also make a higher or lower frequency by changing the speed of the rock movement. Is there anything similar that can be done with radio waves? Generate a lower frequency with a smaller antenna by pushing the power through slower?

I'm not sure if that's possible, if you could change the speed of electricity going through a wire, assuming that's what it would take. Is that possible?

From other info I'm reading, current flows faster if it is fed into a thinner wire. So theoretically, could you run a regular line to a thicker antenna to get a slower current? And would this effectively give you a lower frequency in transmitting a radio wave than if you used the the regular diameter antenna?

submitted by /u/nosoupforyou
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Isn't the separation of mixed oil and water decreasing entropy?

Posted: 05 Jun 2016 03:24 PM PDT

How can humans tell how much time has passed?

Posted: 05 Jun 2016 06:47 PM PDT

Hey everyone,

We humans have created time, a construct that standardized when we do activities around the globe. But how can we tell how much time has passed without looking at a clock? I never confuse 5 seconds passing with one minute passing. How do we do it?

We have nerves that sense when we are touching objects, chemicals that can create feelings of hunger, and detectors that can sense how much oxygen we have in our system...but if I am sitting in a room staring at a wall, how is it that my brain can easily distinguish between 5 minutes passing and 30 minutes passing?

Obviously, within that 30 minutes of staring at the wall, you would have many more thoughts than you would have in 5 minutes...but number of thoughts alone cannot possibly be what allows us to tell how much time has passed, because we are thinking at different rates constantly.

When we fall asleep however, whatever time sensor we have seems to shut off. Waking up 1 hour after falling asleep can easily trick me into thinking I've been asleep for 8.

What creates the feeling of time passing?

submitted by /u/Peanutbuttered
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Sunday, June 5, 2016

What is the biggest distinguishable difference between Alzheimer's and dementia?

What is the biggest distinguishable difference between Alzheimer's and dementia?


What is the biggest distinguishable difference between Alzheimer's and dementia?

Posted: 04 Jun 2016 06:33 PM PDT

I know that Alzheimer's is a more progressive form of dementia, but what leads neurologists and others to diagnose Alzheimer's over dementia? Is it a difference in brain function and/or structure that is impacted?

submitted by /u/ebreedlove
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When two unrelated people look a lot alike, do they actually a more similar genome than average, or are their similar looks completely coincidental?

Posted: 05 Jun 2016 03:02 AM PDT

What's the chance of having drunk the same water molecule twice?

Posted: 05 Jun 2016 06:27 AM PDT

Does the expansion of the universe increase the travel time between the earth and another point of the universe ?

Posted: 05 Jun 2016 04:52 AM PDT

When you're 'fighting a disease' what does that battle look like? do your white blood cells just absorb bacteria/illness and kill them? What happens?

Posted: 04 Jun 2016 09:20 PM PDT

Why do dogs like to play fetch? Is this a behavior only found in domesticated dogs?

Posted: 05 Jun 2016 12:55 AM PDT

Are the intestines "in order"?

Posted: 04 Jun 2016 08:09 AM PDT

Ok, so this might be a strange question, but every time you see a depiction of the intestines it looks like a rope, that you try to fit into a small place without properly tangling it up. And if people in movies,tv etc. are severely injured, their belly sliced open and their intestines fall out, they kind of hang out of there like a rope.

So my question is, if that was to happen, is there any order or system to put in back in in surgery or do you just try to "make it fit"?

Please excuse the informality of the language, I just tried to paint an accurate picture of my problematic understanding.

These depictions are meant: NSFW !!!

http://img.webmd.com/dtmcms/live/webmd/consumer_assets/site_images/articles/image_article_collections/anatomy_pages/intestines.jpg

And this one, of a man with his intestines hanging out: AGAIN NSFW NSFW

https://riversofgrue.files.wordpress.com/2013/08/dream-home-movie-guts-intestines-evisceration.jpg?w=450&h=294

submitted by /u/clique_clique
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Is it possible to change your "fight or flight" response through training?

Posted: 05 Jun 2016 03:46 AM PDT

[Biology] Do I have the same DNA throughout my whole life?

Posted: 05 Jun 2016 01:27 AM PDT

If we compare my DNA when I was a baby with the DNA I will have when I'm old, would the two be different?

submitted by /u/ThisUsernameIs20ltrs
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If I were to have 100 flashcards, and I randomly sampled 10 at a time, is there a way to calculate statistically how many times I'd have to sample to see all 100?

Posted: 04 Jun 2016 09:08 AM PDT

Google didn't understand what I meant. Is there a name for this type of statistical calculation?

If I had any knowledge about programming, I'd have the program randomly pick 10 numbers, keep track of them, but rerun the random drawing of 10 numbers until all numbers are accounted for and then stop. The number of runs it made reported at the end. Do this enough times and I think we'd get a nice curve. However, if there was a way to do this using a formula, it would be much nicer.

I know they can calculate the probability cloud of an electron in an atom and that was not by brute forcing it but by using advanced math. I'm hoping someone knows of a way to do the same thing in this scenario. And if it has a name, I'd like to know it.

submitted by /u/secretman2therescue
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Why is schizophrenia considered a mental disorder, while Alzheimer's is considered a disease?

Posted: 05 Jun 2016 02:00 AM PDT

Schizophrenia Alzherimer's

Is alcohol addiction a disease or a disorder?

submitted by /u/muddahungry
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Is there enough space in the observable universe to write down the number of digits in Graham's Number?

Posted: 04 Jun 2016 03:17 PM PDT

If not, is there enough space to write how many digits are in the number of digits in Graham's number? If the answer is still no, then how many iterations would it take before arriving at a number small enough to write?

submitted by /u/InteriorEmotion
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When/How did Earth get water?

Posted: 05 Jun 2016 01:43 AM PDT

From my understanding of the history of the Earth, it started out as just a big rock covered in lava (magma?) some-billion years ago. And then, a few billion years later, it had some water, which then held life. Now, where the life came from is a question for another time. But, where did the water come from?

submitted by /u/jacdeswilliams
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Does the Time you Choose to Sleep at Have an Affect on your Health?

Posted: 05 Jun 2016 03:46 AM PDT

Growing up in an Asian family, I was told that sleeping and rising earlier was good for you. For example instead of sleeping at 12 and waking at 8, I sleep at 10 and wake up at 6; the total amount of time I sleep does not change, but the time period that I choose to do so does. I could not find any reliable sources on the topic and I am wondering if this is true or a myth.

submitted by /u/toasternuke
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Can someone explain the concept of gravitational potential between 2 masses?

Posted: 04 Jun 2016 08:00 AM PDT

I am struggling with the concept of gravitational potential. I know that by definition it is the work done in moving a unit mass from infinity to a point in the gravitational field (GPE per unit mass), but I don't truly grasp what this means and its significance. I also don't really get how gravitational potential is defined between 2 bodies, such as the earth and the moon. If we talk about bringing an object from infinity into the gravitational field of Earth I can visualise that, but how do you define the potential at a point where 2 fields act (such as that of the moon and the earth)? Where is 'infinity' in this case? Is there a point of 0 potential between the 2 bodies, where essentialy the strengths of the gravitational fields are equal and there is no resultant force on a body at that point, so no gravitational potential? I am only doing A2 physics (pre university) so a simple explanation will suffice.

submitted by /u/mickey_w
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Do other animals see face patterns in inanimate objects like humans do?

Posted: 04 Jun 2016 09:48 AM PDT

I forget the name, but I'm aware of the phenomenon where people see faces in things that aren't really faces. Last night, I was wearing a shirt with my school's sports logo on it, a flat depiction of a large cat. My Dad jokingly held up our cat to look at the cat on the shirt and she didn't really react to it at all.

This made me wonder whether or not she even recognized the collection of flat, solid colors on my shirt as the face of a cat in the same way we do.

submitted by /u/Darthelmet1
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When I walk up a flight of stairs, am I burning the same amount of energy (i.e. calories or joules) the gravitational potential energy that I've created?

Posted: 05 Jun 2016 06:59 AM PDT

For example, I weigh about 90 KG. If I go up 8 meters on a few flights of stairs - basic physics says that Mass x Accel. of Gravity x Height = the potential energy created in lifting that object to that height. In that example, 90 KG * 9.8 m/s2 * 8 meters = 7,056 joules, or about 1.7 kCals. So, am I burning exactly that amount in walking up those stairs? Or is there something else going into that equation? Is my body that efficient? Is 100% of the energy that my body creates in going up those stairs created by the food that I've eaten, or does something else (like the oxygen I'm breathing) play a part? Thanks!

submitted by /u/spr0922
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Do small insects such as Thripses have hearts and brains too? If not, how do they operate/live?

Posted: 05 Jun 2016 03:07 AM PDT

Why do heavy metal ions, for example Cu2+ cause proteins to coagulate?

Posted: 05 Jun 2016 02:54 AM PDT

Can anyone simply explain the mechanisms that protect the small intestine from the digestive juices released by the biliary system and pancreas?

Posted: 05 Jun 2016 02:47 AM PDT

Are there different nerves for pain than for other senses and motor activities?

Posted: 05 Jun 2016 12:21 AM PDT

I am confused about why pain killers only deaden pain and don't e.g. make your arm numb or make it impossible to move it. Are there two (or more) independent sets of nerves? Like one for pain and others for the other senses and motor activity? Or is there only really one nervous network and pain killers just somehow affect its activity? Or does no one really know?

submitted by /u/d33ms
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Why do some chemical reactions need catalysts (such as potassium permanganate), and what does the catalyst do if it is not used up?

Posted: 04 Jun 2016 09:52 PM PDT

For example: we have the decomposition of hydrogen peroxide (H2O2) into hydrogen (H2) and oxygen (O2). This happens in the presence of a potassium permanganate catalyst. Why is the potassium needed? How can it be part of the reaction if it is not a part of the product or reactant? What does it do to cause the reaction?

submitted by /u/the_quassitworsh
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Are galaxies currently forming or have they been established for some time?

Posted: 04 Jun 2016 10:46 PM PDT

How did geneticists first discover which parts of the human genome were "exons" and which were "introns"?

Posted: 04 Jun 2016 09:10 PM PDT

In the human genome only 1.1% of the genome is spanned by exons, whereas 24% is in introns, with 75% of the genome being intergenic DNA.

How was this discovered? How exactly did we find the exact regions for exons?

submitted by /u/Zeekawla99ii
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