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Saturday, February 20, 2016

Why doesn't the immune system kill incoming sperm?

Why doesn't the immune system kill incoming sperm?


Why doesn't the immune system kill incoming sperm?

Posted: 19 Feb 2016 03:42 PM PST

Would gravitational waves be a suitable replacement for RF in communications in the distant future?

Posted: 20 Feb 2016 06:15 AM PST

Why does spicy food clear sinuses and cause perspiration?

Posted: 19 Feb 2016 08:06 PM PST

I saw somebody else had asked this question a long time ago, but that answer didn't feel satisfactory, especially since I'm now studying in the Biomedical Engineering field. Does the capsaicin bind to a receptor that induces sweating?

submitted by /u/1stbaser
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What happened to US presidential election voter turnout between 1896 and 1920?

Posted: 19 Feb 2016 10:47 AM PST

Here's a chart from Wikipedia.

submitted by /u/e8odie
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Pleochroism vs Birefringence, same or different?

Posted: 19 Feb 2016 03:03 PM PST

TLDR: What's the difference?

I learned a new word recently from the Skeptic's Guide to the Universe podcast; pleochroism. I am a lab tech in a hospital lab. We perform crystal exams on synovial fluid. In our procedures we call the crystals birefringent if, under polarized light, they display a different color when oriented parallel than perpendicular to the axis of the light source. MSU crystals are blue when perpendicular to the axis while they are yellow when parallel. This seems to be more like pleochroism than birefringence. Clarify it for me.

submitted by /u/RvnClw
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How long would it take to brute force the encrypted iPhone that the FBI wants Apple to decrypt?

Posted: 19 Feb 2016 04:57 PM PST

Setting aside legal or moral debate and just speaking straight cryptology/computer science, is it possible to decrypt that phone in a reasonable amount of time?

submitted by /u/zinchalk
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What happens to radioactive elements when they're cooled to near absolute zero / super heated into a plasma?

Posted: 20 Feb 2016 04:19 AM PST

Does the Cosmic Microwave Background increase the lowest measurable temperature ?

Posted: 20 Feb 2016 05:44 AM PST

We know the Cosmic Microwave Background has a temperature of 2.7 Kelvin ...Does that mean that the lowest measurable temperature is -273.15 °C or -275.85 °C but we can't actually create the latter ?

And if we can cool below the CMB temperature, how do we do it ? Can there be naturally occuring temperatures lower than CMB ?

submitted by /u/katzmarek
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Why doesn't the human body reject new blood (i.e. from transfusions) in the same way that it often rejects new organs?

Posted: 19 Feb 2016 12:19 PM PST

What are the differences between alpha particles and helium nuclei?

Posted: 19 Feb 2016 10:00 AM PST

Why does 1-propanol has higher boiling point than 2-propanol?

Posted: 19 Feb 2016 11:35 AM PST

They have the same intermolecular forces, but their molecular structure is different.

submitted by /u/Ibrah7
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When I'm in an area with "spotty" phone/data service and my signal goes in and out even though I'm keeping my phone perfectly still, what is happening? Are the radio waves moving around randomly like the wind?

Posted: 18 Feb 2016 08:47 AM PST

Do gravitational waves stretch time like they do space?

Posted: 19 Feb 2016 09:28 AM PST

If so can this be measured? Would a gravitational wave change the rate at which atoms like cesium vibrate?

Physics

submitted by /u/Gzogzez88
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I am a resident of Miami, Florida and my mom is convinced the entire city will be underwater in 25 years. While I know this is false I don't have any evidence to back up my claim. Can someone knowledgeable on the subject tell me why this is false and at what time Miami will be underwater?

Posted: 19 Feb 2016 09:01 AM PST

How do scientists compare animal intelligence to their equivalents in human children at certain ages?

Posted: 19 Feb 2016 07:01 AM PST

I've read many times that Border Collies are potentially as smart as 4-year-old kids, dolphins are compared similarly, etc.

submitted by /u/SnowGryphon
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What neurological differences are there in a crow's brain that allow it to have such high intelligence for its size?

Posted: 19 Feb 2016 05:26 AM PST

If the sum of all natural numbers is -1/12, what is the sum of all negative whole numbers to negative infinity?

Posted: 19 Feb 2016 12:36 PM PST

I saw a video of a proof that the sum of all natural numbers from 1 to infinity was -1/12 and it blew my mind, so it made me think what the sum of all negative whole numbers to negative infinity would be. Is it the same analogous result or + 1/12?

submitted by /u/blackhawk767
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Do black holes and hurricanes/vortexes look similar mathematically?

Posted: 19 Feb 2016 06:53 AM PST

I was looking a picture of a vortex and realized visually, black holes and vortexes look identical. Does the math share this similarity? Do the equations found in transport phenomena and fluid mechanics have similarities with the ones we used to predict black holes?

submitted by /u/poosymon
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Do black holes exist or not?

Posted: 19 Feb 2016 07:50 AM PST

Hi everybody! After seeing a lot of "black holes related questions" in AskScience I remebered reading articles back in 2014 which said that someone proved mathematically that black holes can not form and do not exist. So what is true about that? Do black holes exist or not?

Articles I've meant: http://phys.org/news/2014-09-black-holes.html

And this is (I believe) the paper: http://www.sciencedirect.com/science/article/pii/S0370269314006686

Disclaimer: I'm no native speaker, sorry if there are any mistakes.

EDIT: format

submitted by /u/t3error
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In our solar system, are the distances of planets from the sun random or is there a mechanism at work like in the electron shells?

Posted: 19 Feb 2016 08:22 AM PST

Friday, February 19, 2016

AskScience AMA Series: We're Drs. Kerry Emanuel and Dan Cziczo, professors in MIT's Program in Atmospheres, Oceans, and Climate. We study the physics of the atmosphere and climate, and are teaching a free MOOC on Global Warming Science. Ask Us Anything!

AskScience AMA Series: We're Drs. Kerry Emanuel and Dan Cziczo, professors in MIT's Program in Atmospheres, Oceans, and Climate. We study the physics of the atmosphere and climate, and are teaching a free MOOC on Global Warming Science. Ask Us Anything!


AskScience AMA Series: We're Drs. Kerry Emanuel and Dan Cziczo, professors in MIT's Program in Atmospheres, Oceans, and Climate. We study the physics of the atmosphere and climate, and are teaching a free MOOC on Global Warming Science. Ask Us Anything!

Posted: 19 Feb 2016 04:34 AM PST

I'm Kerry Emanuel, a Professor of Atmospheric Science at the Massachusetts Institute of Technology in Cambridge, Massachusetts. I do research on hurricanes and other types of severe weather, on climate change, and how climate change might affect severe weather. My research is mostly theoretical, but I also build computer models and occasionally participate in field experiments and build and use laboratory experiments. I have flown research aircraft into hurricanes, and wrote a book called "Divine Wind: The History and Science of Hurricanes", aimed at a general reader and covering both the science of hurricane and how they have influenced history, art, and literature.

I'm Dan Cziczo, an Associate Professor in Atmospheric Chemistry at MIT interested in the interrelationship of particulate matter and cloud formation. My research utilizes laboratory and field studies to elucidate how small particles interact with water vapor to form droplets and ice crystals which are important players in the Earth's climate system. Some of my group's experiments include using small cloud chambers in the laboratory to mimic atmospheric conditions that lead to cloud formation and observing clouds in situ from remote mountaintop sites or through the use of research aircraft. More generally, my research interests include: Chemical composition of atmospheric aerosols with an emphasis on their effect on cloud formation mechanisms, Earth's radiative budget, and meteoritic debris and launch vehicle emissions in the atmosphere.

This week, we started the second offering of our massively open online course (MOOC) on "Global Warming Science", which you can register for free to take at here at EdX. We think it's a great way to learn the science behind how the Earth's climate system works, and about both past and future climate changes. Best of all, you'll be taking the class with thousands of people from all over the world - from students to researchers to professionals in many different careers and from many different walks of life! Three of our doctoral students from MIT are helping to TA and will be available to help us answer any questions you might have during the course. Additionally, David McGee, an Assistant Professor in Climate Physics and Chemistry at MIT is also teaching the MOOC, but is unable to join us today (although he's happy to answer any questions you might have on the course forum!)

We look forward to answering your questions about our research and our climate MOOC at 10AM EST! Ask us almost anything!

EDIT - 10:10 AM (EST) - We're online answering your questions! We'll be around for about 1-1/2 - 2 hours to chat. Note that /u/kerryemanuel is indeed Professor Emanuel's real account.

submitted by /u/GlobalWarmingMOOC
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My physics textbook says that small redshifts of galaxies are due to their velocities relative to us, while large redshifts would be caused by expanding space stretching wavelengths. Is it really necessary to make a distinction like this, and can redshift be explained through a particle model?

Posted: 18 Feb 2016 12:42 PM PST

Thanks in advance!

submitted by /u/manyb
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How does infrared light heat objects up?

Posted: 19 Feb 2016 02:47 AM PST

I've been learning about the photoelectric effect in my physics class, and one of the formulas that I learnt was that the energy of a photon of light is given by E=hf. From this equation, ultraviolet light has more energy than infrared. So why is infrared able to heat up objects and ultraviolet not?

Temperature is a measure of the average kinetic energy of an object, so wouldn't a higher energy light transfer more energy?

submitted by /u/Haweraboy
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Does Earth have the most varied elemental composition in the solar system?

Posted: 18 Feb 2016 08:45 AM PST

On the surface, Earth looks like a very diverse planet compared to the monotone wastelands of the other planets. However, I wonder if this translates to actual elemental diversity, I.e. a relatively high standard deviation of atomic number.

submitted by /u/TehoI
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Can you Find new prime numbers by multiplying all of the known prime numbers and adding 1?

Posted: 19 Feb 2016 01:43 AM PST

Our teacher showed us the proof to that there is an infinate number of prime numbers by using Euclid's theorem. If you add 1 to the product of all known prime numbers is it garanteed to get a new prime number? And if so why are people still looking for new prime numbers?

submitted by /u/Unholydude
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Is there a 'Goldilocks zone' for planet rotation, ie, if the planet rotates too fast or too slow, does it prevent the formation of life?

Posted: 18 Feb 2016 08:37 AM PST

I was thinking about this on my way to work this morning. I know that if a planet is too far or too close to a star, then it's too cold or too hot to form life (according to modern theory at least). But if it's a matter of heat and sunlight, then would rotation matter?

If a planet was tidally locked for example, so that one side was super hot and the other super cold, would it make it harder for life to form? Or if the planet orbited several times an hour and the light energy was dissipated, would that have an effect?

submitted by /u/hippiechan
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Approx. how many earths could fit in the newly discovered record breaking super-massive black hole in galaxy NGC 4889?

Posted: 18 Feb 2016 10:25 AM PST

If meditation is good for the brain, is the opposite of mediation(chaotic, unfocused thoughts) bad for the brain?

Posted: 19 Feb 2016 06:00 AM PST

Why wasn't poor vision phased out through evolution?

Posted: 18 Feb 2016 07:37 PM PST

What will be registered to the brain first? A sound, or a sight?

Posted: 18 Feb 2016 05:49 PM PST

Can I power a solar panel with a UV light? If so, will it go faster or slower?

Posted: 18 Feb 2016 05:59 PM PST

Where does energy go?

Posted: 18 Feb 2016 08:20 PM PST

If matter and energy can be neither created nor destroyed, what happens when matter is converted into energy in digestion for instance, and then that energy is used? What happens to that energy/matter and is it still around in some form.

Also, since I just read The Last Question by Asimov and the big question is whether entropy can be reversed here's another question. As I understand it, maximum entropy will be when the energy of the universe is evenly spread out across the universe and everything is in one homogeneous state. But if E=MC2 and matter and energy can neither be created nor destroyed but just change form would there be matter/energy at the end of the universe that would pool together due to gravity and glob up and de-homogenize the universe?

submitted by /u/TheTimolosophy
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If temperature is the speed of atoms in matter, is there a temperature of a single moving atom/nucleus?

Posted: 19 Feb 2016 06:14 AM PST

If so, when you accelerate hydrogen nuclei in a particle accelerator, can you say that they become hotter the faster they move?

submitted by /u/1foxman1
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Why do small holes seem to bend light?

Posted: 18 Feb 2016 05:44 PM PST

If you bring a small hole to your eye, it seems to bend and distort light. What processes are at play to cause this?

submitted by /u/Ehiltz333
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How are we finding such intact remains of Neanderthals, yet Denisovans/other homonins remain out of grasp, so to speak?

Posted: 18 Feb 2016 08:23 AM PST

Ever since I was a child , my parents have told me that drinking cold water while eating fatty meats is bad for your digestive health. Is there any truth to this ?

Posted: 18 Feb 2016 07:23 AM PST

So , every time I am having dinner with my parents , they tell me that I shouldn't drink cold water during a meal that consists of fatty meats . Their belief is that the cold water will make digestion more difficult and will cause long term damage to my digestive system . Seems bogus to me and I have not been able to find any supporting studies on the subject . Thoughts ?

submitted by /u/oneofthosepimps
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Would an object falling in a vacuum with unlimited space to fall eventually reach the speed of light?

Posted: 18 Feb 2016 06:54 PM PST

Can the Van der Waals forces be applied to every molecule?

Posted: 18 Feb 2016 08:52 AM PST

For example, can every Hydrogen bond be explained with Van der Waals, or are they different?

submitted by /u/NerfdaDerf
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Let's just say that the LHC had a place that you could open up and get inside the collider. What would happen if particles were accelerated to maximum speed and you stepped in front of them?

Posted: 18 Feb 2016 11:06 PM PST

Are there any actual health or mental benefits to having plants in your house?

Posted: 18 Feb 2016 10:47 AM PST

Not by use of plants as medicine or anything of that variety. Just by them purely being around you.

submitted by /u/Economy_Cactus
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What difference is there from humans, in certain animals stomachs, that allows them to eat rotten food and not get ill?

Posted: 19 Feb 2016 01:37 AM PST

How exactly does the reverse Hermann Grid work?

Posted: 18 Feb 2016 12:00 PM PST

Here is the illusion What is happening at the intersections versus the non-intersections in regards to receptive field activity?

submitted by /u/lycaonxxx
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What effect does ambient temperature have on how well something burns?

Posted: 19 Feb 2016 04:22 AM PST

For example, does a bonfire burn better during the day than the night? Or does it have no effect whatsoever?

submitted by /u/dad_is_on_fire
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If we ever get to do brain transplants, what would happen? Would the person with the new brain have the new brain old memories, or would all memories be forgotten?

Posted: 18 Feb 2016 04:20 PM PST

Or... would he have he's old memories...?(I think thats impossible)

submitted by /u/NiftyFish
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Thursday, February 18, 2016

Do dyslexics have issues with all symbols, or just letters?

Do dyslexics have issues with all symbols, or just letters?


Do dyslexics have issues with all symbols, or just letters?

Posted: 17 Feb 2016 08:17 PM PST

If a person with dyslexia saw a Chevy logo or the batman symbol, is there a chance that it would be flipped around?

submitted by /u/holy_halo_man
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Can fruit DNA (like from an apple or orange) be traced back to the tree it came from?

Posted: 17 Feb 2016 07:49 PM PST

Why is a Gaussian "bell" curve showing normal statistical distribution the shape that it is? What formulæ or proofs define its shape?

Posted: 17 Feb 2016 04:22 PM PST

Do you need both a -10 and -35 sequence for a promoter to bind?

Posted: 17 Feb 2016 08:05 PM PST

Just a bit of background. I have a DNA sequence I am trying to interpret and there is a -10 sequence for RpoD (regulatory gene regulator) and there is no -35 sequence that matches a promoter for RpoD. However, at the -17 position I have a sequence that matches AlgT (sigma factor/transcription factor) and a promoter sequence at -42. Is it possible for the RpoD to only bind at the -10 sequence and initiate transcription? Is it possible for AlgT to initiate transcription even if it is 17 nucleotides downstream of the promoter?

submitted by /u/roilyerf
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Why can or can't I move differentials around an equation?

Posted: 17 Feb 2016 04:19 PM PST

I am currently working towards a bachelor's in mechanical engineering and I was wondering about calculus differentials. Quite often in class, we move them around freely and a professor will say something along the lines of "If you are a mathematics major, this probably makes you cringe. Technically you can't move differentials around but we can in this field." (physics or engineering) So basically my question is why is it that you cannot technically move them around, yet I do it all the time when solving problems?

submitted by /u/frenchsko
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How does the Genetic Maternal Effect differ from Cytoplasmic Inheritance?

Posted: 17 Feb 2016 07:58 PM PST

And how do they differ from Genomic Imprinting?

submitted by /u/Suck_A_Turd
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Why do we need to postulate the presence of dark matter? Wouldn't unexpected astrophysical phenomena simply indicate that our understanding of gravity in inadequate?

Posted: 17 Feb 2016 06:54 PM PST

It seems to me to be a great jump to postulate the existence of a new type of matter in response to astrophysical observations not lining up with predictions as dictated by current theory. Would not the more parsimonious response be to work on modifying the theory? Do we really need dark matter to explain our observations?

submitted by /u/Benthos
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How do red/green ganglion cells detect red?

Posted: 17 Feb 2016 08:54 PM PST

I'm studying neuropsych and reading about trichromatic theory.

I undesrstand that a green signal is sent from the ganglion cell if the dominant stimulus it recieves is from M rather than L cone cells. Because M cones are stimulated by around 530nm light, which corresponds to green light on the wavelength spectrum.

But a red signal is triggered by stimulus from L cone cells, which respond to 560nm light..... but that's yellow?? Is my textbook wrong, shouldn't L cones respond to red light, such as 680nm? If not, how does the eye detect red light?

submitted by /u/Kaiped1000
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What is the probability of one target being hit by a ball?

Posted: 18 Feb 2016 06:08 AM PST

Suppose I have 4 targets. I can throw a ball four times. The ball hits one random target every time I throw it. What is the probability of the ball hitting the first target at least once?

One of my classmates says that the probability is 100%, but everyone else disagrees. What's the correct solution?

EDIT: The targets are reusable; they can be hit more than once.

submitted by /u/Hallodusch123
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Why do we always try to stop the swelling that occurs upon spraining or breaking a bone?

Posted: 17 Feb 2016 04:57 PM PST

Also, if it is so detrimental to recovery, why does the body do it?

submitted by /u/Cesare_MA
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I find entropy to be an interesting concept, but why do we research it? Why is it significant?

Posted: 17 Feb 2016 06:39 PM PST

I remember learning about it back in 1st year chem, but I never really grasped why it is important. To me it just seems like a cool theoretical concept, and I feel like I am missing something.

submitted by /u/privilegedhere
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It is possible to recover data from sticks of RAM if they are snap frozen, before they are pulled out?

Posted: 17 Feb 2016 08:38 PM PST

So I'm sure I saw this in a movie once. A guy breaks into a company / data centre and need some info / passwords that are on the computer. He steals the RAM because the data is stored unencrypted in memory. However because the RAM is volatile, it will loose the information if the power is disconnected. To compensate for this, he uses a spray can of some gas (maybe freon?) to freeze the RAM. This gives him a few minutes to pull the RAM out of the machine and get out of the building and re-energise it in a computer, before the RAM loses the data.

Is there any validity to this?

submitted by /u/Electr0Fi
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Are there any effects of brain hemisphere lateralization?

Posted: 17 Feb 2016 08:33 PM PST

I read this in my consumer behavior textbook. http://imgur.com/U4ZDEFR Is the information accurate? Does brain lateralization have any effects on behavior? I am weary to believe anything of brain lateralization after learning that left/right brain personality theory is not necessarily true.

submitted by /u/hasway
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Why do cold temperatures make your digits numb?

Posted: 17 Feb 2016 06:01 PM PST

Half life period of radioactive substance?

Posted: 18 Feb 2016 03:59 AM PST

I know that half life period is the the time required for a substance to decay half of it's initial amount.My question is that many radioactive element have a huge life time in order of billion years.so how some atoms of the radioactive substance stays without decaying for such a long time.

radioactive elements are unstable and and gain stability by decay process so why not every atom decay as fast as possible.

I also don't understand concept of probability in radioactive decay.

submitted by /u/ILART
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What season was on Pluto when New Horizons passed by ?

Posted: 18 Feb 2016 01:45 AM PST

What happens to the ectrons and protons in a neutron star?

Posted: 17 Feb 2016 05:11 PM PST

How come this dude can carry highly enriched Uranium 235?

Posted: 17 Feb 2016 05:54 PM PST

Was reading this article on wikipedia[1] and got confused because some guy is holding some "highly enriched uranium 235" with only rubber gloves.

If it isn't really hot, then how is this uranium used to produce heat for nuclear reactors?

submitted by /u/SquirrellsOfThunder
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In beta positive decay, isn't mass created?

Posted: 17 Feb 2016 03:51 PM PST

In the process, a proton decays into a neutron, which has more mass than a proton, a positron, which has mass, and an electron neutrino, which has mass. Therefore, although things like charge and lepton number are conserved, mass is not. What is going on?

submitted by /u/tunaMaestro97
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Are the humerus bones in the left and right arms different? Or are they mirror images of each other?

Posted: 18 Feb 2016 04:42 AM PST

Can electricity be used to convert ADP to ATP in the presence of excess inorganic phosphates?

Posted: 17 Feb 2016 12:54 PM PST

Sorry if the question is phrased improperly, but after doing some reading about oxidative phosphorylation it (perhaps incorrectly) occurred to me that the electron transfer chain that fuels the conversion of ADP to ATP is comparable to electricity. Could actual electrical current be used to fuel the same process?

Again, my apologies if the question is phrased poorly.

submitted by /u/writers_block
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What effects does chronic stress have on muscle growth?

Posted: 17 Feb 2016 04:09 PM PST

In terms of working out/body building does chronic stress have an effect on the outcome of muscular growth?

submitted by /u/spudlyjoe
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Why is snake venom required to make anti-venom?

Posted: 17 Feb 2016 12:49 PM PST