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Monday, January 23, 2017

[Physics] Why do charges flow from positive to negative?

[Physics] Why do charges flow from positive to negative?

[Physics] Why do charges flow from positive to negative?

Posted: 23 Jan 2017 05:26 AM PST

Why do some insects have hemoglobin while others have hemocyanin?

Posted: 22 Jan 2017 05:34 AM PST

How do scientists determine the age of cave paintings?

Posted: 22 Jan 2017 08:02 PM PST

Is it possible using software to determine the hardware circuits of a computer system?

Posted: 22 Jan 2017 01:32 PM PST

You can obviously find out a few basic things about hardware you're running with software programs; the amount of RAM channels, control operations on the microprocessor, etc, but how much further could you theoretically go in determining exactly the structure/nature of the circuits on which the software is running?

submitted by /u/b00gi
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Why are there long strips of land along the eastern coast of the US? What formed them?

Posted: 22 Jan 2017 03:45 PM PST

All along the eastern coast of the US, there's these oddly thin protrusions of land: http://imgur.com/a/2peSE

What caused these? Are there coasts with similar attributes?

submitted by /u/SykoKiller666
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Why don't incandescent light bulbs need any cooling, but LED lamps require it?

Posted: 22 Jan 2017 01:25 PM PST

Old bulbs didn't require any cooling even in the 100-200W range. But LEDs need passive cooling after few W and active cooling over ~20 W. Why is that?

submitted by /u/akosprojects
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What happens if someone seals a completely empty box in space and brings it to earth?

Posted: 22 Jan 2017 07:23 PM PST

My thermos has a vacuum, but my coffee still gets cold. If I bring home a vacuum from space, what will happen? Will I be able to use it to keep my coffee hot forever? Will the box close in on itself?

Thanks in advance for all the answers!

submitted by /u/gr8gh0st
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Do organisms with shorter lifespans evolve faster?

Posted: 22 Jan 2017 12:23 PM PST

What gets split with a signal splitter?

Posted: 22 Jan 2017 05:00 PM PST

I have an attic installed antenna. I took a basic EE course back in college, but the details for antennas have been lost to the cobwebs of my mind. As the Radio-Frequency wave impacts the metal of an antenna, the electrons move in concert with the wave. That movement is sent transferred to a coaxial cable to a junction box, where I split it to the TVs I desire to decode the signal. I have a 1-3 splitter that is labeled -3.5db, -7db, and -7db. My question is: what exactly is taking a 3.5 or 7db loss? The induced current (I could see that based on Kirchoff's current laws)? the signal to noise ratio? The induced voltage traveling down the wire? All of the above and more? Something else? I'm very curious what property is actually taking a loss. I remember hearing at one point there was no point in amplifying after a split, because you can't drag more signal up out of the noise, is that true? Thanks!

submitted by /u/CheeseOrion
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How did computers evolve to have no moving parts?

Posted: 22 Jan 2017 05:57 PM PST

I've read that the earliest computers had to be physically rewired in order to write a new program to the computer. How is it that now we can just write new programs without having to physically alter the wiring inside a computer? What is it about the actual computer code that allows it to be so flexible and do so many different things without having to physically manipulate the computer parts?

submitted by /u/Twarren8178
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How does electricity "know" the path of least resistance?

Posted: 22 Jan 2017 11:22 PM PST

In a parallel circuit, current splits at a node and will tend to flow towards a branch with a lower resistance value. How is this possible? I assume this has to do with the quantum mechanical aspect of matter?

Bonus questions : in what conditions can a gas become a conductor? Do they offer advantages over conductors such as copper?

submitted by /u/eexistencee
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Why do people occasionally wake up aroused?

Posted: 22 Jan 2017 08:14 AM PST

It's a common phenomenon across seemingly all ages and genders. What causes it? Is it something to do with erotic (but unremembered) dreams? Incidental stimulation of the genitals during sleep? Something else?

I'm not referring to erections, here, but rather arousal in general, and am interested in this phenomenon in all genders, not just men.

submitted by /u/trippysnail
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Why do ultracold 87 Rb atoms behave as bosons?

Posted: 22 Jan 2017 03:55 PM PST

I was reading one of my textbooks on Evaporative cooling and came across a list of Bose-Einstein condensates . I was suprised to see 87 Rb. Why does evaporatively cooled 87 Rb behave as a boson?

submitted by /u/Diggle3
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How do photons accelerate to c?

Posted: 22 Jan 2017 09:31 PM PST

If I turn on an LED, out comes the photons - what causes them to accelerate to c? Seems like a little 9V battery would have quite enough... Oomph.

submitted by /u/mrlaptopman1
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What is TV static and how does it come to be?

Posted: 22 Jan 2017 09:06 PM PST

Can spectral flux density be negative?

Posted: 22 Jan 2017 05:08 PM PST

I was reading through a paper and on Figure 1B the spectral flux density is shown, where the axes themselves are on linear scales. The blue curve on this plot in particular corresponds to the Stokes V parameter (i.e. circular polarization), yet appears like it goes slightly negative in this case. I was simply wondering how that could be as I thought this was related to intensity and was always positive.

submitted by /u/CallMeDoc24
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How do muscles grow in the average healthy adult male?

Posted: 22 Jan 2017 08:44 PM PST

Besides other factors (diet, genetics, testosterone and steroid use), how do muscles grow through exercise only?

submitted by /u/Regor400
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How big is our 'North Star" compared to these objects in this video?

Posted: 22 Jan 2017 02:32 PM PST

Do larger birds grow larger feathers?

Posted: 22 Jan 2017 09:45 AM PST

If bosons are force carriers, which force does the Higgs carry?

Posted: 22 Jan 2017 07:52 PM PST

What makes the Higgs different? I always see it as not in the same category as the other bosons, which account for Electromagnetism, Strong interaction, and Weak interaction.

I understand that there's a Higgs field, but I've never heard of a higgs 'force'.

submitted by /u/Megaprr
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Does parental blood type influence miscarriage or development?

Posted: 22 Jan 2017 03:23 PM PST

I've read about different/rare blood types such as A2, etc. Knowing that a fetus gets their type from mother and father, and might not be the same blood type as mom, how does that impact fetal development and mom's health?

submitted by /u/NewMaterialOnly
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Do viral infections reduce an organisms lifespan?

Posted: 22 Jan 2017 04:17 PM PST

As per the Hayflick Limit, most vertebrate cells can only divide between 50 and 70 times. However, when viral infections occur, many cells undergo viral lysis, and are destroyed - I presume that after the infection is defeated, nearby cells have to divide in order to repopulate the damaged tissue.

As such, do those divisions count towards the Hayflick Limit? Would having had a large number of viral infections (all of which are survived) decrease an organisms lifespan by causing tissues to end up undergoing premature senescence? Or, do infections and the immune response trigger the production of telomerase?

submitted by /u/Ameisen
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Sunday, January 22, 2017

Can water be frozen in an airtight container?

Can water be frozen in an airtight container?

Can water be frozen in an airtight container?

Posted: 21 Jan 2017 07:14 AM PST

The picture of the Coke pushing the lid up on the bottle on /r/all made me curious. If you put water in a container that left no space around the water and wouldn't break, could you freeze the water? If so (or if not), what would it do?

submitted by /u/seanbeandeathscene
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Is there a single culture in this world where people have no names? if so, how does it affect their notion of identity?

Posted: 21 Jan 2017 03:39 PM PST

Why does overclocking a CPU make it unstable?

Posted: 22 Jan 2017 05:57 AM PST

I'm interested to know what physical processes make CPUs less stable at higher clock speeds. I imagine it might be similar to the idea of transistors smaller than 10 nm having issues with quantum tunneling. Why does the varying purity of the silicon (dubbed as the silicon lottery) affect how well a chip can overclock? Thanks!

submitted by /u/DanielDC88
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How can astronauts see Cherenkov radiation?

Posted: 21 Jan 2017 08:13 AM PST

I saw a talk on space vessel design, and heard that astronauts in low earth orbit can perceive radiation visually through Cherenkov radiation, which gets generated inside the eyeballs' vitreous body (the gallert 'filling' of the eyeball). How and why does this work, and why does it not work on earth, only in space? (That part of the talk was mostly focused on low-earth orbit vessels inside the magnetic field, such as the ISS)

submitted by /u/dumpkwestion
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What difference does water temperature make on plants? Would a river of hot water have unique foliage?

Posted: 21 Jan 2017 03:32 PM PST

For instance, if a hot spring produced enough water to have a steadily flowing river, would its surroundings still be similar to normal rivers?

submitted by /u/whalesloth
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Is it possible that humans percieve colors differently?

Posted: 21 Jan 2017 01:59 PM PST

I have been wondering about this for a while now. Is it possible that each person see colors differently? For example, when I see the color orange, is it possible that my wife sees it as what I would call purple? We can both point to it and say, "That is orange!", because to us, it is our version of orange. But if I were able to see though her eyes, with my current perception of colors, it would appear to be purple.

How could this be tested. Has it been tested? Any thoughts or comments?

submitted by /u/GR33NBEARD
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Does change in Gibbs free energy need to be negative for a nuclear reaction to be feasible?

Posted: 22 Jan 2017 02:55 AM PST

Title says it all really but I could only find chemical reaction stuff relating to Gibbs free energy

submitted by /u/zestypikelet
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Why do torque and work have the same units if they represent different quantities?

Posted: 21 Jan 2017 02:48 PM PST

If a high wattage laser is invisible, you still need eye protection to use it?

Posted: 21 Jan 2017 05:50 PM PST

If its an infrared laser, can it damage your eyes if you use it without laser protective goggles?

submitted by /u/user7160
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Is it possible for a substance to be composed entirely of protons, like neutronium?

Posted: 22 Jan 2017 01:15 AM PST

I know there's something called protonium where an antiproton and proton orbit eachother, but is it possible for a "protonium" to exist where the substance is 100% densely packed protons (or electrons or quarks or any other subatomic particle)? I know the like charges would repel extremely strongly, but with sufficient gravitational forces would it be possible?

Also, in the event it is, how dense would such a substance be? Much denser than neutronium, right, since protons are denser than neutrons?

submitted by /u/ted234521
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Would it be possible to create an ice engine which works based on pressure similar to a steam engine?

Posted: 21 Jan 2017 08:53 PM PST

What if you had large container you could fill with water, leave it out somewhere very cold and let it freeze. Could the pressure created by the water expanding do meaningful work? Would it be possible to continue the process indefinitely with a source of running water & cold environment? Simply dump the ice when it's frozen and fill it up again to keep it going?

submitted by /u/LeaningLamp
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Why do certain curves minimize time for a mass to descend? (see video)

Posted: 21 Jan 2017 09:07 AM PST

Referring to this video: http://i.imgur.com/5t32VJU.gifv

All balls have equal GPE at start, and at the end. Why does one curve cause the balls to go faster?

submitted by /u/pseudonym1066
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Is it possible to burn wood (or other biomass) as dry fuel in order to make electricity carbon neutral?

Posted: 21 Jan 2017 06:12 PM PST

Some coal power plants do co-combustion with biomass waste products such as palm husks, pine, etc... in order to have a % of their emissions come from current carbon, thus have a lesser impact on global warming. If you grew some biomass to burn as a fuel source (not co-combustion), would it be carbon neutral if you kept replanting more biomass in its place? Could that be sustainable?

I know that there are other environmental impacts from burning biomass, but I and wondering specifically about the impact on net CO2 levels.

submitted by /u/5cience_mama
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Does light get faster when it is affected by a bigger gravity?

Posted: 21 Jan 2017 12:14 PM PST

So for example when Light is affected by the Earths gravity is it slower than when Light is affected by the gravity of a black hole? I'm just curious, because from what I recall Light from a certain distance would be faster at the Black hole than Earth. After thinking a little bit about it I thought that gravity doesn't need to affect the speed of light but rather the direction to make it faster the bigger the gravity gets. PS: I'm so sorry if you don't understand my question, because of the bad wording, grammar or spelling.

submitted by /u/Taebak88
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Why is there such a thing as escape velocity?

Posted: 21 Jan 2017 12:02 PM PST

Can't we just send something into orbit (or just straight away from Earth, for that matter) nicely and slowly?

submitted by /u/disintegrationist
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How many image combinations are possible on a 1000x1000 grid?

Posted: 21 Jan 2017 06:38 PM PST

I tried doing some basic math with RBG (0 - 255) and came up with a number that seems way too small (1.658e+13). The idea that you can think of anything and it would potentially be in that image is mind-blowing. I feel like an idiot just doing (255 ^ 3) * (1000 * 1000). I feel like a better calculation would be something like (255 ^ 3) C 1000 C 1000. Not entirely sure, though.

submitted by /u/Voxelsdev
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Article on new plate tectonics theory. How is this different from what I learned in school 20 years ago?

Posted: 21 Jan 2017 09:57 AM PST

So I read this article expecting to learn something new, but it sounds just like convection cells that I read about in elementary school a long time ago. What am I missing?

http://www.businessinsider.com/what-moves-tectonic-plates-2017-1

submitted by /u/didyoubikethat
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When someone recalls a sensation, what parts of the brain are involved?

Posted: 21 Jan 2017 01:12 PM PST

Essentially, when someone is remembering/recalling/imagining a sensation, such as a visual image or a touch on the arm or a smell, what parts of the brain are activated? If the feeling is touch, for example, does the primary somatosensory cortex get activated like it does when the touch actually occurs?

submitted by /u/Jnicky69
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Will a bullet shot from a gun hit the ground at the same time an identical bullet is dropped from the same height?

Posted: 21 Jan 2017 09:12 AM PST

In my physics lecture yesterday, my professor did a demonstration where he used some equipment(I don't remember what it's called) that dropped a ball and shot a ball out perpendicular to it and they both hit the ground at the same time. I can't wrap my head around this working from shooting a bullet out of a gun. Assuming you shot it in a field where nothing will get in the way of the bullet.

submitted by /u/NinjaWithACokE
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Saturday, January 21, 2017

Can birth defects be detected in eggs or sperm?

Can birth defects be detected in eggs or sperm?

Can birth defects be detected in eggs or sperm?

Posted: 20 Jan 2017 10:13 PM PST

Why flunitrazepam or benzodiazepines decrease delta wave activity (or time in slow wave sleep)? What are the first few studies discovering this fact?

Posted: 20 Jan 2017 06:50 PM PST

Dear friends and professionals on r/askscience:

The Wikipedia page of flunitrazepam states:

"Flunitrazepam produces a decrease in delta wave activity. The effect of benzodiazepine drugs on delta waves, however, may not be mediated via benzodiazepine receptors. Delta activity is an indicator of depth of sleep within non-REM sleep; increased levels of delta sleep reflects better quality of sleep. Thus, flunitrazepam and other benzodiazepines cause a deterioration in sleep quality."

But without noting what studies do these facts come from. I have putted "citation needed" tags on them. Could someone please answer me: Why flunitrazepam or benzodiazepines decrease delta wave activity (or time in slow wave sleep)? What are the first few studies discovering this fact?

submitted by /u/wiseschizo
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How were radio waves discovered?

Posted: 20 Jan 2017 05:59 PM PST

I've googled Maxwell's equations, but I don't understand it.

You would first have to understand electromagnetic waves, both in light and electricity, then expand the concept to conceive of, and include wavelengths that we have no means of perceiving.

How did the concept of waves come about from the experience of light and electricity? And how did it lead to theorizing and proving the existence of waves outside of those we can directly experience?

submitted by /u/KritiosMan
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When a photon redshifts, it's wavelength becomes larger, which corresponds to a lower photon-energy. What happens with this energy difference?

Posted: 21 Jan 2017 05:19 AM PST

Was the ground more fertile when the giant dinosaurs and other animals were around?

Posted: 20 Jan 2017 04:15 PM PST

I ask because larger animals have larger BMs. Since poop can be used as fertilizer, wouldn't more poop on the ground mean more fertile land?

submitted by /u/UppercaseVII
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Where does NASA get its old (e.g. 1884) climate data?

Posted: 20 Jan 2017 12:37 PM PST

Friend of mine contests that climate change data is invalid because of poor sampling technique and data collection.

One of his points of contention is that the old data was not reliable enough to cite, e.g. http://climate.nasa.gov/vital-signs/global-temperature/ has a chart of data from 1884.

I don't see on that page where that data is from or how it was gathered. Do others know?

submitted by /u/bnovc
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Is there a "universal speed limit" lower than the speed of light for an object of a given mass?

Posted: 20 Jan 2017 01:07 PM PST

Let's say there's a 100kg object traveling through space. Obviously it can't reach the speed of light because it has mass. But since we know its mass, do we know how fast it can go according to the laws of physics? Or could it theoretically reach 99.9999999% of c but just never quite reach c?

submitted by /u/graaahh
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If you flip a coin an infinite amount of times, will you also at some point have an infinite streak of heads?

Posted: 20 Jan 2017 08:41 AM PST

[Social Science] is there any evidence that publicly available databases for offenders, such as Megan's Law, have decreased incidents of said offenses?

Posted: 20 Jan 2017 12:57 PM PST

For anyone who doesn't know, in the U.S., people who commit a crime of a sexual nature against a minor are placed in a database for public viewing, which includes their residence and photograph, among other things (Megan's Law). My understanding is that this is a permanent thing and violators are not able to remove themselves from the database.

I recently heard that the federal gov't is presenting an idea for a similar database to Megan's Law for juveniles and adults who commit animal abuse crimes, so I wondered how effective it would actually be.

submitted by /u/teamchuckles
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How much iron is required to stop the sun's fusion process?

Posted: 20 Jan 2017 04:43 PM PST

The Colour Force gets infinitely strong at a distance - so how are we breaking apart protons at the LHC?

Posted: 20 Jan 2017 02:09 PM PST

So I definitely am missing something - I was under the impression that the colour force holding quarks together gets infinitely strong as distance increases.

If this is true - are we 'breaking' protons in the LHC? If so, how?

Or are the protons 'healed' from other particles popping into existence from the vacuum?

Someone tried to explain this to me but I got very lost.

Thanks!

submitted by /u/ohmscience
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If all of a female's eggs are created while she is still in utero, why does the probability of having a child with a chromosomal abnormality (like Down's syndrome) rise with age?

Posted: 20 Jan 2017 02:43 PM PST

How does medicine/antibiotics know how to "attack" and "who" to "attack"?

Posted: 20 Jan 2017 03:19 PM PST

How does The Sun have more than 4.6 billion years of fuel?

Posted: 20 Jan 2017 10:46 AM PST

I'm having a "glitch in the Matrix" moment. What I believe are facts:

  • The Sun continually burns through a fuel source that is itself

  • Although it's very big, so is its "burn". It sends Earth enough "heat" to create our climate. I think Earth is apx 100 times the Sun's diameter away -- so, it's like standing in absolute zero, 100M from a fireball that's 1 metre across and being significantly heated. I.e., the output is beyond the scale of normal human experience.

  • The Sun doesn't send its "heat" (or radiation) only in our particular direction. Any Earth-sized body 93 million miles from the sun would get an Earth-sized dose of "sunlight". That must mean its total "heat" in any moment is millions of times the heat we receive. I.e., while it's big, its "burn" is also big.

What I suddenly can't process is: not running out of fuel after 4 billion years.

I mean, if I just learned of the concept of a star -- a really gigantic ball of fire -- my instinct would be that they burn for perhaps 1,000 - 10,000 years before running out of fuel. I'd be surprised at 1 million years. Burning fuel for 5 billion years, and still going strong ... how can that happen?

Did it shrink?

submitted by /u/Biuku
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Are there any gasses with negative GHP? (green house potential)

Posted: 20 Jan 2017 01:54 PM PST

I've seen that sulfur hexafouride has a GHP of 22600 times the GHP of CO2.

I would like to tally up the current greenhouse effect, but it occurred to me that we may also be emitting gasses that have a negative greenhouse effect and that I would need to take these into account for an accurate result.

Thank you.

submitted by /u/uber_kerbonaut
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Concerning the simultaneity paradox of relativity in the "train and lightning" example - Suppose the train has batteries in front and back of the train that dictate if it stops or goes if struck by lightning. Does the train stop running? Clarification in post.

Posted: 20 Jan 2017 10:41 AM PST

Here is a video of the simultaneity paradox I am referencing. Someone standing still on a platform while watching a train pass by at close to c sees and concludes that two bolts of lightning strike the front and back of the train at the same time. Due to the fact that an observer inside the train perceives light's speed as constant regardless of direction of travel, she sees and concludes that the bolt of lightning hit the front of the train before the back of it. The order of events are different to both observers, yet both are correct for their respecitve reference frames.

So here is my thought experiment. Suppose there is a battery at the front and rear of the train. If the front battery is struck, the train keeps going (even if both are struck at the same time). If the rear battery is struck, the train stops.

Okay, so the observer standing still on the platform sees two bolts of lightning hit both batteries on the train. Since the front battery was hit, and this battery keeps the train going when struck with a bolt, the train keeps running regardless of the fact that the rear battery was struck.

However, an observer inside the moving train perceives the front battery being hit first, and then the rear battery being hit second. The front battery gets struck, so the train keeps running. But then the rear battery was hit alone, so the train must stop.

So what happens when lighting strikes both batteries - Does the train stop or not? How does each person perceive this? How do we reconcile this?

submitted by /u/AlbanianDad
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Why do some babies learn to walk or run faster than others? What is that indicative of?

Posted: 20 Jan 2017 10:26 AM PST

Why does friction cause heat?

Posted: 20 Jan 2017 01:43 PM PST

Could there be enough tectonic plate activity since the last interglacial period to make a 6-9 meter difference in sea depth or is tectonic plate activity too slow compared to glacial/interglacial periods?

Posted: 20 Jan 2017 05:22 AM PST

I saw that sea levels were 6-9 meters higher during the last interglacial period on a recent Science post. Is there a way to tell whether the change was due solely to melted ice and higher temperatures or is it possible that tectonic activity changes the height of land masses & depth of oceans to the extent that the geologic record indicates sea levels higher than we'd expect with todays tectonic plate arrangement? This is definitely the case for sea beds from dinosaur days now being dry land. Could there be enough tectonic plate activity since the last interglacial period to make a difference or is tectonic plate activity too slow compared to glacial/interglacial periods?

submitted by /u/a5121221a
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What is the. Heisenberg Uncertainty Principle?

Posted: 20 Jan 2017 07:10 AM PST

I read the explanation on Wikipedia, but I don't think I understand. Why does it get harder to determine location as you determine momentum?

submitted by /u/forte_bass
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In mammals, what determines the average number of babies born during one pregnancy?

Posted: 20 Jan 2017 01:59 PM PST

Mammals like cats and dogs produce several babies while humans, on an average, produce only one baby during a pregnancy.

submitted by /u/oswaldthatendswell
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Can someone please explain what "clean coal" technology entails?

Posted: 20 Jan 2017 05:21 PM PST

The new white house page on energy says:

The Trump Administration is also committed to clean coal technology, and to reviving America's coal industry, which has been hurting for too long.

What do they mean by "clean coal" technology, and how will it impact our environment?

submitted by /u/Jehovacoin
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