| What makes most books smell good? Posted: 26 Dec 2015 07:07 AM PST |
| Would today's nuclear fail-safes prevent a disaster like Chernobyl in a similar situation? Posted: 26 Dec 2015 05:29 PM PST Specifically, a disaster functionally identical to the Chernobyl disaster, but with today's security mechanisms. submitted by CodyTechery [link] [65 comments] |
| Since a focal point can theoratically be infinitely small and photons have an impulse, does this mean that we could theoratically create an "impulse-singularity"? Posted: 27 Dec 2015 04:46 AM PST In physics class my prof told me that a focal point can theoratically be 1-dimensional. I don't know too much about photon-impulse, but shouldn't that mean that we can focus a certain impulse on an infinitely small "area", meaning 1 point? Would this have any interesting consequences? submitted by Ausderdose [link] [11 comments] |
| if a rocket going at 1000 m/s ejects fuel at 500 m/s, relative to it, where does the energy go? Posted: 27 Dec 2015 03:26 AM PST assuming the fuel weighs the same as the rest of the craft (for example) then the exhaust gasses would decelerate by 250 m/s and the craft would accelerate by 250 m/s, following newtons 3rd law, meaning the overall velocity would remain the same. So were does the chemical energy from the fuel go? submitted by ThatSaneGuy [link] [13 comments] |
| How does photon-photon interaction not misconstrue the paths of other photon-photon interactions throughout space? Posted: 26 Dec 2015 07:16 AM PST Here is a diagram to help explain So this is really hard for me to explain, and I'm afraid that my explanation is going to be very rudimentary... so I needed to draw a diagram to aid me... This is a concept that has always bothered me, and I can't seem to understand why it is the way it is... If I am sitting in the position of the star near at bottom of the attached image, how do the photons reaching my eye stay unaffected from the photons that are traveling towards the diamond from the triangle? It's just hard to comprehend the mess of interaction at the midpoint of the diagram. In my head, it seems that at that center point, all of the light-particle interactions should create some sort of "globular" mess that would otherwise impact the information traveling in the form of photons... If light travels as a wave, then how do the wave-interference interactions not cancel or "change" the photons entering my eye? If light is a particle, then how do they not "deflect" each other as they are meeting at the center? It's all very confusing to me... but I'm sure there is a solid explanation... Of course this is a simple example, but as I try to imagine the rest of the world in all its complexities, I always get back to this simple example. Seems like the world should really be one giant mess visually, but turns out that it's incredibly aesthetic and works itself out like fine poetry... Sorry if this sounds "unscientific", and also for the very crude diagram. Thanks a bunch in advance! submitted by fali12 [link] [31 comments] |
| What would an observer, moving faster than the local speed of light in a medium (eg. water), see? Posted: 26 Dec 2015 09:33 AM PST |
| Would Earths atmosphere get blown away if we would hit a gas cloud in space? Posted: 26 Dec 2015 09:54 AM PST |
| How can space be cold? Posted: 27 Dec 2015 05:32 AM PST It is my understanding that if you go to space without a space-suit, you will freeze. But how can that be? If heat is 'stored' in the vibrations of the atoms involved, and there's no atoms around you to transfer those vibrations to, how can the heat leave your body, so to speak? And on top of that, why doesn't the sun keep you warm? I mean, there's nothing like atmosphere to remove energy from the sun's rays before they hit you, so shouldn't it be really hot? Sure, the rays only hit you, and doesn't warm up your surrounding air and the ground beneath you, but still. Can somebody explain this? submitted by AF79 [link] [1 comment] |
| Is it possible to have a planet without any fixed axis of rotation? Would such a planet's days and nights be basically random in terms of their periodicity and duration? Posted: 26 Dec 2015 12:23 PM PST Related to that, why do we have a fixed axis and why are we not just tumbling around in space? Is it because the earth is not perfectly spherical and so it has to do with the unequal distribution of mass? If earth were a perfect sphere would be able to rotate around all axes? submitted by bangsecks [link] [6 comments] |
| How does increasing torque decrease the angular speed of a rotating shaft? Posted: 26 Dec 2015 01:50 PM PST By definition, if we increase a torque we should increase the angular speed, right? Why is it that when we hold power constant the opposite is true? When we shift gears in a car to first gear, we have more torque, right? Why don't we also have more speed seeing how more torque = more angular acceleration? submitted by TorqueDatAssGurl [link] [7 comments] |
| If Pi is an infinite series, and has every possible combination of numbers, wouldn't there be a segment with all the previous numbers in it starting with 31415...? Posted: 26 Dec 2015 04:34 PM PST |
| If space in the universe is expanding and space is a part of spacetime, does it mean that time is expanding as well? Posted: 26 Dec 2015 05:00 AM PST |
| How would the boundary between the liquid and solid core of a planet look? Posted: 26 Dec 2015 07:58 AM PST I've been thinking about the solid core of the earth every since I saw a reference to it somewhere on reddit, and it popped to my mind that there has to be a point where the solid core seperates itself from the liquid, is this a gradual process, how does the superhot molten iron behave RIGHT before turning solid from the pressure? submitted by Pyrelord [link] [2 comments] |
| At what level does the expansion of the universe occur? Posted: 26 Dec 2015 07:36 AM PST I was watching an episode of PBS's excellent Space Time series, in which the host responded to the question, "How can an infinite universe expand?" The host compared the universe to an infinitely long ruler. Although the ruler itself is infinitely long, the units on the ruler (e.g. centimeters) are finite. Expansion of the universe is equivalent to doubling the distance between each unit. This got me wondering about what level the expansion occurs on. Is this a purely classical effect, or does it occur at the quantum level as well? If it is classical, does expansion start at the Planck length (which I understand to be the minimum size at which classical effects can occur) or at some larger unit? submitted by Meta4X [link] [27 comments] |
| Did warlike cultures performed eugenics unintentionally? Posted: 26 Dec 2015 09:12 AM PST If they were warlike only the fit ones survived also considering the fact that there was rape involved in some raids could also mean that the strong ones spread their genes more. So basiclly my question is: did warlike cultures did eugenics without even noticing? submitted by Not_A_Unique_Name [link] [10 comments] |
| [Archaeology] When the Bible was written did anyone know about dinosaurs? Posted: 25 Dec 2015 10:39 PM PST |
| Do animal species other than humans have cultural variation? Posted: 26 Dec 2015 04:33 AM PST I admit that my knowledge regarding animal behaviour is fairly limited. I also do not know whether we consider collective behaviour in animals a form of culture. We know that many animal species have some set guidelines for doing things. Be it sociopolitical hierarchies or leisure activities, animals display some level of cultural norms. I wonder if these animals also have some form of cultural diversity within their species. I can't be sure which flair is appropriate for this. If a mod could help out it'd be great, thanks. Edit: Automod told me to get a flair already.
submitted by Gaethan [link] [6 comments] |
| [Biology] Why was there a lack of domesticable animals in the Americas? Posted: 26 Dec 2015 01:25 AM PST |
| Can we ever achieve a horizontal-launch into space? Posted: 26 Dec 2015 04:03 AM PST What I mean is, if you see the moon on the horizon and you want to fly straight for it instead of launching vertically upwards first into space. Is this ever possible? submitted by crewnots [link] [8 comments] |
| How are cosmetic products scientifically tested for safety? Posted: 26 Dec 2015 04:25 AM PST I'm interested in knowing more about how cosmetic products are tested for safety. What kind of scientific tests are cosmetic products subjected to? How much would each of these tests cost? As a consumer - if I wanted to test for the composition and safety of a cosmetic product, what kind of tests should I request from a private laboratory? Would a generic chemical analysis be enough? submitted by bonito_broth [link] [2 comments] |
| How could a crystal like this be grown in the lab as they state? Posted: 25 Dec 2015 11:12 PM PST |
| What role does electricity play in mental state/memories/maintaining cognitive consistency? Posted: 25 Dec 2015 11:34 PM PST So as far as I know, the brain is a network of neural synapses and different processing structures that work together to create the conscious experience. I'm not sure, though, how much of this information is stored physically, for example in the rearrangement of synapses or in the restructuring of the brain. Is any information, for example mental state or memories, simply an abstraction of different electrical states of the brain? What would happen if we were to "zap" the brain and completely reset its electrical state? Would it no longer function? Does an electrical state need to be maintained in the brain at all times, or could we shut off a brain and fire it back up later? If so, what would change? Any memory loss or change in personality? Some of these questions may be impossible to answer I suppose Thank you submitted by psilocyTim [link] [2 comments] |
| Would significantly altering the speed of light to be faster or slower have any observable changes in our universe? Posted: 26 Dec 2015 12:04 AM PST I know there is a limit to light speed but what if the laws of physics were so that it was twice as fast. What would change? Also what if it was twice as slow? Other than the light from the sun getting to earth in 16 minutes than in 8 I can't really wrap my mind around any quantum or atomic changes of anything as a result of. submitted by Hazard_Warning [link] [38 comments] |
