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Sunday, February 21, 2016

On tv a while ago, Brian Greene said that we may see gravity as the weakest force because it may only exist partly in our universe and partly in another. Is this considered a credible theory today? If so, would the gravity waves we've observed be traveling through those other universes as well?

On tv a while ago, Brian Greene said that we may see gravity as the weakest force because it may only exist partly in our universe and partly in another. Is this considered a credible theory today? If so, would the gravity waves we've observed be traveling through those other universes as well?


On tv a while ago, Brian Greene said that we may see gravity as the weakest force because it may only exist partly in our universe and partly in another. Is this considered a credible theory today? If so, would the gravity waves we've observed be traveling through those other universes as well?

Posted: 20 Feb 2016 05:27 PM PST

He was comparing gravity to the strong & weak nuclear forces, and electromagnetism.

submitted by /u/Algernon_Moncrieff
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Is there any actual evidence that multiple dimensions and universes exist?

Posted: 20 Feb 2016 04:50 PM PST

Is it possible for liquids to be physically damaged?

Posted: 20 Feb 2016 11:12 AM PST

I'm going to use an example. If by chance I have a quart of synthetic motor oil and drop it from a very high building in its container(the container doesn't break) will the oil still be in perfect condition or would it be damaged and not reccomended for use. Other than my example, any other ways certain liquids could succumb to physical damage?

submitted by /u/OmgRan
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Why can't normal batteries be recharged?

Posted: 20 Feb 2016 06:31 PM PST

If you could strike one side of an atom is there a propagation delay before the far end of the atom knows to start moving? Do they deform in some way...i.e. as a tennis ball when it is struck?

Posted: 20 Feb 2016 09:43 AM PST

I'm trying to understand the "pushing a steel rod" example, that if you push a steel rod there is a propagation delay before the other end knows to move. The example always seems to be that the information in the wave propagates atom-to-atom along the rod compressing the distance between the atoms, but does the wave deform the atom itself as it passes along in some way? I get that nothing is instantaneous and the information needs to move through the atom in some way, but I've never heard if/how the atom itself changes, or if the particles in the nucleus or the electron shells actually deform in some way like a tennis ball in response to the propagating wave.

submitted by /u/SureIllrecordthat
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What does it mean to "be Bayesian" in terms of a way of thinking?

Posted: 20 Feb 2016 10:03 AM PST

I'm familiar with Bayes' Theorem and how it's used in problems, but I've heard people talking about having a Bayesian way of thinking in general, or statisticians subscribing to a Bayesian way of thinking. What exactly does this mean? Is there more to Bayesian reasoning than just solving probabilities?

submitted by /u/MrNov
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Y-chromosome DNA can be used to trace male ancestry. Mitochondrial DNA can be used to trace female ancestry. Do we have enough information from each to make any useful statement about whether Neanderthal DNA in modern humans is mostly from male or female ancestors, or from both equally?

Posted: 20 Feb 2016 08:59 AM PST

In other words, can we determine whether male Neanderthals were more commonly breeding with contemporary female H. Sapiens in a way that contributed to current human DNA, or vice versa? Or can we see that both combinations have left a broadly equivalent trace? Or do we simply not have enough information (so far)?

submitted by /u/GreyShuck
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Biochemically, why does the methyl group of meth cause it to be so much potent than other amphetamines?

Posted: 20 Feb 2016 01:47 PM PST

What exactly about the Higgs Boson or the Higgs field gives matter mass?

Posted: 20 Feb 2016 09:10 AM PST

How long it took for Charon to freeze completely?

Posted: 20 Feb 2016 11:09 AM PST

There was news recently that Charon may have had a liquid ocean under ice crust. The speculation was based on cracks on Charon's ice crust. So I wonder how long time Charon could have had the liquid ocean or part of it?

submitted by /u/trenchgun
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How does hyperparathyroidism and hypercalcemia cause hypomagnesemia?

Posted: 20 Feb 2016 07:02 PM PST

How does hyperparathyroidism and hypercalcemia cause hypomagnesemia? I know it's pretty far-fetched, but I've tried google but to no avail. Yes, I've read my books, but I couldn't wrap my head around the concept. Answers are really appreciated. Thank you!

submitted by /u/tryingtopasstheclass
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I've heard that GPS satellites have to compensate for relativity to stay accurate. What specifically do they have to compensate for?

Posted: 20 Feb 2016 07:08 AM PST

Is the difference in time due to them being farther from our gravity well or does it have to do with the speed that they are moving? Or is there something else?

submitted by /u/OctavianDresden
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At what point in evolution did mammals gain the ability to synthesize vitamin D from sunlight?

Posted: 20 Feb 2016 11:42 AM PST

Just curious.

submitted by /u/Juno_Malone
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If we accept that gravitation is an effect of distortions in spacetime, why do we still try to unify gravity with the other forces?

Posted: 21 Feb 2016 12:48 AM PST

Doesn't the warped spacetime idea mean that two masses "accelerating" toward each other due to gravity are, in fact, not accelerating at all but each just following their respective path in spacetime? It seems to me that since the objects aren't directly interacting with each other that this makes gravity fundamentally different from the others, no?

submitted by /u/probability_of_meme
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Where did early organisms get their energy if there were no other organisms to digest and no photosynthesis?

Posted: 20 Feb 2016 11:09 AM PST

In a closed system, life couldn't exist on earth because there would be no energy input. However, with the sun giving off energy, it's possible. Animals eat other animals which ate plants which used photosynthesis to get energy from the sun. But what happened before photosynthesis evolved? For even a single celled organism to divide, it needs energy. Absorbing another organism might make sense, but that organism would have needed to find energy as well. Aren't even nutrients full of potential chemical energy that had to come from somewhere?

submitted by /u/sagacious_1
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Why do we have separate systems for myelination of the central and peripheral nervous systems?

Posted: 20 Feb 2016 12:42 PM PST

I assume it has a reason due to evolution, but all I can find with google are differences between oligodendrocytes and schwann cells. I can't find anything about why they are separate systems.

Thanks!

submitted by /u/walksalot_talksalot
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Does electromagnetism distort space time like gravity?

Posted: 21 Feb 2016 12:01 AM PST

How is mass converted to the energy of gravitational waves?

Posted: 20 Feb 2016 10:19 AM PST

In the recently detected waves, three solar masses worth of black hole ... stuff ... was converted into gravitational waves. But any two masses orbiting each other produce waves, even if they're undetectable. Those waves are carrying energy, which apparently comes from a reduction of mass in the system. How does that work?

I'll pick an example: the earth-moon system is radiating gravitational waves at a frequency of about 4 x 10-7 hertz at some teeny tiny eentsy beentsy wattage. Is the ordinary, non-black-hole-matter mass of the system shrinking by that same wattage? How?

submitted by /u/someone_entirely_new
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How many integrated circuits are in a computer?

Posted: 20 Feb 2016 05:09 PM PST

I'm looking for real or approximate numbers in any real-world devices. Yes, I know it depends on the computer. What is the complexity scale of what we're dealing with? Are there 10 integrated circuits in a computer? 10,000? Impossible to quantify because they overlap somehow? I have no idea and extensive searches on Google aren't helping me.

submitted by /u/ktool
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Doppler Effect, where does the energy go ?

Posted: 20 Feb 2016 04:30 PM PST

Hi, I have some questions about the doppler effect and was wondering someone could help me understand. With the phenomenon called the doppler effect, the frequentie of for example an electromagnetic wave (such as a lightbeam) will change due to the movement of the emitter or it being bounced of of a moving object. Now the famous formula of Max Planck tells us the energy an electromagnetic wave equals the planck constant times the frequentie of the wave. Now my question is, where does this energy, due to the change in frequentie, go ?

submitted by /u/JamesLed
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What is the scientific consensus on the effect of vegetarian and vegan diets on health?

Posted: 20 Feb 2016 07:00 AM PST

I've yet to find a comprehensive/peer reviewed meta analysis of vegetarian or vegan diets. Opinions tend to be 'it's good for you' or 'it's bad for you'. I'd like to see or hear some actual science!

submitted by /u/islamicporkchop
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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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