On Earth, we have time zones. How is time determined in space?

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• On Earth, we have time zones. How is time determined in space?
• Since dinosaurs were discovered far below the earths surface covered in dirt, how does the earth gradually pile dirt on itself, forming layers covering up history over the past few centuries?
• When people are born with extra, functioning appendages, are they also born with unique brain regions for controlling them?
• Does sleep deprivation cause permanent damage to the brain?
• How is it that the recently discovered “oldest spiral galaxy”, A1689B11, can be so well formed yet exist only 2.6 billion years after “Big Bang”?
• Do you become more contagious as a cold/flu progresses, or do you pose the same risk to others as soon as symptoms begin to show?
• How is meat "aged"; what is occurring at the molecular level and why doesn't the meat spoil? (Also, cheese)
• Why do older models of cars have long antennas, while newer models have short ones or none at all?
• Why is the colour of an atomic explosion white, and not blue?
• What is aether?
• What benefits and disadvantages does Daylight Savings Time provide, economically?
• Why are many babies born blonde haired but fade to a different color at a later age?
• Why do some human organs regenerate but others don’t?
• Does warm water evaporate quicker than cold water? If so, by how much?
• Do sea creatures have a dominant hand/claw/tentacle?
• Why does NIST use a 60kHz frequency to transmit a 1 byte per second signal? Wouldn’t a lower frequency travel further more reliably?
• Is there any evidence that untargeted murders have shifted from serial killing to parallel killing over the past decade or two?
• Have humans/organisms caused an increase on the overall mass of Earth? ie man made objects or birth of organisms?
• Why don't we have the technology to desalinate ocean water for human use?
• Can fish see color? And if not, why are they so colorful?
• Can allergies of a person with Multiple Personality Disorder vary according to their different personalities?
• How does a bullet perfectly follow the path of the barrel, rather than bounce and vibrate against the sides?

On Earth, we have time zones. How is time determined in space? Posted: 04 Nov 2017 06:58 PM PDT submitted by /u/mikes2123 [link] [comments]

Since dinosaurs were discovered far below the earths surface covered in dirt, how does the earth gradually pile dirt on itself, forming layers covering up history over the past few centuries? Posted: 04 Nov 2017 11:58 PM PDT submitted by /u/squanto420sqanching [link] [comments]

When people are born with extra, functioning appendages, are they also born with unique brain regions for controlling them? Posted: 04 Nov 2017 11:10 AM PDT submitted by /u/paulshnargas [link] [comments]

Does sleep deprivation cause permanent damage to the brain? Posted: 05 Nov 2017 06:38 AM PST I just got over a period of insomnia in which I was regularly going without sleep for several days at a time (this lasted about two weeks, in which I was maybe averaging four hours of sleep a night). Having recovered, I feel fine, but I have anxiety about what this might have done to my future academic performance. Should I be concerned? submitted by /u/compositematerials [link] [comments]

How is it that the recently discovered “oldest spiral galaxy”, A1689B11, can be so well formed yet exist only 2.6 billion years after “Big Bang”? Posted: 05 Nov 2017 05:21 AM PST submitted by /u/aiYeoU [link] [comments]

Do you become more contagious as a cold/flu progresses, or do you pose the same risk to others as soon as symptoms begin to show? Posted: 05 Nov 2017 04:31 AM PST submitted by /u/BrotherGrim [link] [comments]

How is meat "aged"; what is occurring at the molecular level and why doesn't the meat spoil? (Also, cheese) Posted: 05 Nov 2017 02:27 AM PST Question in the title. I'm fascinated by what's actually occurring in the process of hanging and aging meat. I understand that you need to agree meat at least a little bit too drain off some blood but what else? Some people use large amounts of salt to make their cheaper bits of meat look and taste better whilst other times people tenderise it with a mallet. What's going on there too? And if anyone is interested enough, what the hell's up with cheese and maturing that for many years? submitted by /u/Buggaton [link] [comments]

Why do older models of cars have long antennas, while newer models have short ones or none at all? Posted: 05 Nov 2017 05:41 AM PST submitted by /u/kevin_time-spacey [link] [comments]

Why is the colour of an atomic explosion white, and not blue? Posted: 05 Nov 2017 05:21 AM PST As you can see from this image the colour of stars depend on the temperature of the star. My search shows that an atomic explosion is about 106 Kelvin. So shouldn't the colour of the explosion be blue? submitted by /u/asking_about_things [link] [comments]

What is aether? Posted: 05 Nov 2017 03:08 AM PST Not trusting Wikipedia because I aint understanding that. submitted by /u/PM_ME_DEAD_INSECTS [link] [comments]

What benefits and disadvantages does Daylight Savings Time provide, economically? Posted: 04 Nov 2017 08:01 PM PDT submitted by /u/sexrockandroll [link] [comments]

Why are many babies born blonde haired but fade to a different color at a later age? Posted: 04 Nov 2017 03:15 PM PDT submitted by /u/CauseImBatman08 [link] [comments]

Why do some human organs regenerate but others don’t? Posted: 05 Nov 2017 04:02 AM PST submitted by /u/HaveASit [link] [comments]

Does warm water evaporate quicker than cold water? If so, by how much? Posted: 05 Nov 2017 03:24 AM PST submitted by /u/lathaz [link] [comments]

Do sea creatures have a dominant hand/claw/tentacle? Posted: 04 Nov 2017 02:48 PM PDT submitted by /u/Lucas_csgo [link] [comments]

Why does NIST use a 60kHz frequency to transmit a 1 byte per second signal? Wouldn’t a lower frequency travel further more reliably? Posted: 04 Nov 2017 04:13 PM PDT (Sorry, should have added in the title "For the broadcast of the UTC time signal for receipt by atomic clocks and wristwatches in the continental US.") I searched the subreddit and Google and found a lot of history and interesting details, but not the answer to this question. I know that the lower the frequency, the larger the antenna must be (like the enormous land-based ELF broadcasters that were used for deepsea underwater submarine radio), but surely1 there's a happy medium between 60kHz and 76Hz or whatever the ELF solution was that would more reliably reach the continental US and still be more than capable of transmitting 8bps. 1 Citation needed. That's why I'm asking the question. My education in terms of Electricity and Magnetism is only at an AP Physics level, anad that was 19 years ago, so as you can see I may be missing something fundamental here. submitted by /u/FrontColonelShirt [link] [comments]

Is there any evidence that untargeted murders have shifted from serial killing to parallel killing over the past decade or two? Posted: 04 Nov 2017 09:58 PM PDT We've heard a lot about mass shootings, stabbings, and other indiscriminate attacks in the news over the past ten or twenty years. What I'm wondering is whether this represents a culturally-motivated shift in the behavior of nutjobs from serial killings to parallel killings, or an actual increase in indiscriminate murder. submitted by /u/Hydropos [link] [comments]

Have humans/organisms caused an increase on the overall mass of Earth? ie man made objects or birth of organisms? Posted: 04 Nov 2017 07:01 PM PDT submitted by /u/At0mical [link] [comments]

Why don't we have the technology to desalinate ocean water for human use? Posted: 04 Nov 2017 11:53 PM PDT submitted by /u/Spider-land [link] [comments]

Can fish see color? And if not, why are they so colorful? Posted: 05 Nov 2017 01:45 AM PST submitted by /u/DracoMundo [link] [comments]

Can allergies of a person with Multiple Personality Disorder vary according to their different personalities? Posted: 04 Nov 2017 01:06 PM PDT I know it may not be a very scientific way to discover things but I'm watching 'Split' and the psychiatrist in one scene is doing a presentation on Multiple Personality Disorder and she claims that someone can suffer from an allergy to Bee stings in one personality and not suffer the allergy in one of their other personalities, I don't know but Biologically speaking it doesn't sound right to me? submitted by /u/djdjdjordje [link] [comments]

How does a bullet perfectly follow the path of the barrel, rather than bounce and vibrate against the sides? Posted: 04 Nov 2017 11:26 AM PDT Wouldn't each firing have enough variance that the bullet would start ricocheting off the sides of the barrel and slow the bullet down dramatically? submitted by /u/ubccompscistudent [link] [comments]

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What significant differences are there between humans of 12,000 years ago, 6000 years ago, and today?

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• What significant differences are there between humans of 12,000 years ago, 6000 years ago, and today?
• How catastrophic is an earthquake for deep sea creatures?
• Why can't we have a system for dividing by zero the same way we have imaginary numbers?
• Why don't modern cellphones create interferences near speakers any more?
• How does refraction work?
• Doesn't voltage in parallel violate the laws of conservation?
• Does the size of the animal affect the number of RBCs?
• Could a hydrogen bomb use the water in oceans as fuel?
• Reading the post about Uranus and it’s 90 degree axis - Why do planets rotate to start with?
• What things in nature are a binary outcome but not really a 50/50 chance?
• Can a powerful electrical charge go through a non conductor?
• At the top of the Space Elevator, would the centrifugal force be significant enough to feel like reverse gravity?
• Why does salt water have a lower freezing point if it has stronger intermolecular force when compared to water?
• Do animals move while in hibernation?
• Do cats/dogs from foreign, faraway places interact differently than they do with cats/dogs from their own geographic region?
• Is the black layer of my microwave’s window—with lots of little holes—what stops the radiation from getting through the glass?
• Why do nuclear bombs lose power over time?
• If we had all of today's technology in Pompeii in 79 AD, could we have predicted the eruption of Mt. Vesuvius? Could we have done anything to save the city, or at least its inhabitants?
• [University Engineering] How do units squeeze through a Laplace transform?
• What happens when photons hit a single electron atom from multiple angles simultaneously?
• What is the largest organic molecule?
• I just read that the heat death of the universe is predicted to be approx 10^103 years from now, how was that number calculated?

What significant differences are there between humans of 12,000 years ago, 6000 years ago, and today? Posted: 03 Nov 2017 05:46 PM PDT I wasn't entirely sure whether to put this in r/askhistorians or here. submitted by /u/awkwardtechdude [link] [comments]

How catastrophic is an earthquake for deep sea creatures? Posted: 04 Nov 2017 04:12 AM PDT submitted by /u/6873487 [link] [comments]

Why can't we have a system for dividing by zero the same way we have imaginary numbers? Posted: 03 Nov 2017 09:48 AM PDT submitted by /u/SevenTwenty720 [link] [comments]

Why don't modern cellphones create interferences near speakers any more? Posted: 03 Nov 2017 08:12 AM PDT 15 years ago, when my cellphone was near speakers, I'd know a few seconds before that someone was going to call, because the cellphone getting in touch/syncing with the nearest GSM relay would create interferences and the speakers would go BZZZ BZZZZZ BZBZBZ or something like that. Now, why don't modern phones do that any more? I've looked for an answer, and found some clues about why it DID that before, although I couldn't find any clear answer. Most commonly found answer has something to do with (pardon my lack of technical english) frequency bursts going from 0 (not receiving) to X MHz (X being the carrier's frequency) while syncing the call. Even if I can understand why this would create interferences, I'm wondering what has changed today, and why we don't get thoses burst interferences any more. Are modern phones always emitting/receiving, so that there are no "0 to X MHz on syncing" bursts anymore? is it a change in frequencies being used by carriers? something else? submitted by /u/leducdeguise [link] [comments]

How does refraction work? Posted: 04 Nov 2017 05:19 AM PDT I understand that light "slows down" in different mediums. How does the light interact with the different medium? submitted by /u/Proberbly_superman [link] [comments]

Doesn't voltage in parallel violate the laws of conservation? Posted: 04 Nov 2017 07:13 AM PDT Alright, so the rule states that the voltage is the same across elements in parallel. So basically if you have two resistors in parallel, they both get the same voltage. What i don't understand is how does that not violate the laws of conservation of energy? Does that not create energy out of seemingly nowhere? You could just connect resistors in parallel and get more energy. Example: 10v supply, with a single 10Ω resistor connected to the circuit. That is 10w power. Add another 10Ω resistor in parallel, and you have 20w power. What's up with that? submitted by /u/Niev [link] [comments]

Does the size of the animal affect the number of RBCs? Posted: 04 Nov 2017 03:18 AM PDT Please refer me to textbooks or scientific papers that talk about this subject. submitted by /u/icymoonchaser [link] [comments]

Could a hydrogen bomb use the water in oceans as fuel? Posted: 04 Nov 2017 07:08 AM PDT And how big would it have to be? submitted by /u/IsUserNameIsntTaken [link] [comments]

Reading the post about Uranus and it’s 90 degree axis - Why do planets rotate to start with? Posted: 03 Nov 2017 12:49 PM PDT submitted by /u/squirrelforbreakfast [link] [comments]

What things in nature are a binary outcome but not really a 50/50 chance? Posted: 04 Nov 2017 04:28 AM PDT For a crude example (there are exceptions of course) humans are born as either a male or female, but despite this being a 1 or the other scenario is it as clear cut at 50/50? Is one more likely than another? This question isnt just about humans at birth its for all of nature submitted by /u/TheIncompetenceOfMan [link] [comments]

Can a powerful electrical charge go through a non conductor? Posted: 04 Nov 2017 03:58 AM PDT For example, if I were to touch and immensely powerful electrical charge using only a small piece of rubber could it still shock me? submitted by /u/Fleegenson [link] [comments]

At the top of the Space Elevator, would the centrifugal force be significant enough to feel like reverse gravity? Posted: 03 Nov 2017 09:31 PM PDT Here's a diagram of what I'm talking about: https://upload.wikimedia.org/wikipedia/en/2/20/Space_Elevator_Schematic.jpg You're standing in the space station at the top of the cable which is orbiting around the earth beyond geostationary orbit. The centrifugal force keeps the cable aloft, but it also means that anyone at the top should feel a force akin to reverse gravity up there. Could you build a space hotel at the top of the cable? submitted by /u/Rownik [link] [comments]

Why does salt water have a lower freezing point if it has stronger intermolecular force when compared to water? Posted: 03 Nov 2017 10:15 PM PDT "Since ethanol molecules aren't as sticky as water molecules, the temperature has to be a lot lower before the forces of attraction overcome the energy of motion and fix the molecules into their array sites. So, that's why alcohol has a much lower freezing point" In this article (https://news.ncsu.edu/2011/07/wms-alcohol-freezing/), it states that ethanol has a higher freezing point than water's because it has weaker intermolecular force. However, salt water has a lower freezing point and stronger intermolecular force than water. https://www.linkedin.com/pulse/why-does-adding-salt-increase-boiling-point-water-ganesh-tingare Also this website states that "The ion-dipole interaction [of salt water] is stronger than the hydrogen bonding between the water molecules" submitted by /u/xxxk1dz_b0pzxxx [link] [comments]

Do animals move while in hibernation? Posted: 03 Nov 2017 03:44 PM PDT Humans and (many) animals move while sleeping. Do they also move in hibernation? submitted by /u/weissnicht01 [link] [comments]

Do cats/dogs from foreign, faraway places interact differently than they do with cats/dogs from their own geographic region? Posted: 04 Nov 2017 01:09 AM PDT Ignoring obvious differences in spoken languages, it's pretty easy to identify strange/unusual mannerisms and nonverbal language used by people from other cultures. If a cat or a dog were taken from, say, SE Asia and brought to the Midwestern US, would local Midwestern US cats/dogs interact with that cat/dog differently than they would with one from, say, a different region of the US? Have there been any studies on this? I'm just curious as to whether cats/dogs develop noticeably different methods or styles of communication from one region of the globe to another. submitted by /u/Cessnateur [link] [comments]

Is the black layer of my microwave’s window—with lots of little holes—what stops the radiation from getting through the glass? Posted: 03 Nov 2017 02:11 PM PDT Are the holes smaller than the wavelength so it blocks the radiation, or does it serve some other purpose? If it is something else, what stops the radiation from going through the glass? submitted by /u/embiggen_Japan [link] [comments]

Why do nuclear bombs lose power over time? Posted: 03 Nov 2017 07:50 PM PDT submitted by /u/StealthBacon [link] [comments]

If we had all of today's technology in Pompeii in 79 AD, could we have predicted the eruption of Mt. Vesuvius? Could we have done anything to save the city, or at least its inhabitants? Posted: 03 Nov 2017 07:44 PM PDT Reading Wikipedia, I learned that there were precursor earthquakes prior to the eruption, but people ignored them as earthquakes were common in the area. Could today's scientists connect those earthquakes to volcanic activity and issue evacuation orders, or some other countermeasures? Are there any other signs of the coming eruption that we could detect using today's technology? submitted by /u/Abdiel_Kavash [link] [comments]

[University Engineering] How do units squeeze through a Laplace transform? Posted: 03 Nov 2017 12:31 PM PDT Can someone help me understand how units shift around through a Laplace transform? I'm looking at an RLC circuit in the time domain, and I can understand that just fine. I can mostly see how to draw it up in the s-domain but I'm getting lost on keeping track of my units. I want to build the equations in terms of volts, because I'm using KVL. submitted by /u/Khufuu [link] [comments]

What happens when photons hit a single electron atom from multiple angles simultaneously? Posted: 03 Nov 2017 11:00 PM PDT Does the electron cloud absorb both photons or just one? Does the nuclei absorb the missed photon? submitted by /u/JoeOfTex [link] [comments]

What is the largest organic molecule? Posted: 03 Nov 2017 10:48 AM PDT I've been learning organic chemistry, about molecules like CH4 and C2H6, and was wondering how big they got. Like how many carbons and hydrogens does the biggest one have? submitted by /u/jeray2000 [link] [comments]

I just read that the heat death of the universe is predicted to be approx 10^103 years from now, how was that number calculated? Posted: 03 Nov 2017 08:11 PM PDT submitted by /u/CptSnowcone [link] [comments]

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Uranus' axis is rotated onto its side, meaning it spins "up and down" instead of "side to side". Does this different rotation have a significant effect on the planet's climate? Could an earth-like planet with that sort of rotation sustain life if all other conditions were ideal?

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• Uranus' axis is rotated onto its side, meaning it spins "up and down" instead of "side to side". Does this different rotation have a significant effect on the planet's climate? Could an earth-like planet with that sort of rotation sustain life if all other conditions were ideal?
• Will planting trees offset my cars carbon emissions?
• What determines how a drug is administered (e.g. orally, anally, injected)?
• Why does an oil/soap film look colored due to interference when everyday light is not coherent?
• Quarks can change flavours but can they change colour?
• Is there a limit to how long a radio wave can be? Would extremely long waves be of any use?
• What's the maximum height a fly or a mosquito can reach?
• Does the severity of an anaphylactic response increase with each exposure to an allergen?
• Why do our bones regenerate?
• Can I use two point sources to accurately simulate a bar magnet?
• If a photon is emitted and absorbed by high-level and low-level electrons respectively, is it stored in the electron and drawn out or does it just pop into existence? If it just pops into existence, where does that energy come from?
• Why does staring at a fixed point in a dark room create the illusion of blindness?
• Would we be able to differentiate between an engineered biological weapon and a natural super-virulent flu?
• Gravity on an ellipsoid?
• What is actually happening when helium affects the sound of our voice?
• Why do songs get stuck in our head?
• Why does faster than light travel equal time travel?
• Does putting alcohol into a fancy looking decanter necessarily make it taste better?
• How do different nuclear bombs fuse or fizz materials?
• In what cases would you want a leading vs. a lagging power factor and vice versa?
• Considering the relative nature of velocity, are momentum and inertia the same thing?

Uranus' axis is rotated onto its side, meaning it spins "up and down" instead of "side to side". Does this different rotation have a significant effect on the planet's climate? Could an earth-like planet with that sort of rotation sustain life if all other conditions were ideal? Posted: 02 Nov 2017 10:08 PM PDT submitted by /u/MrKrixpy [link] [comments]

Will planting trees offset my cars carbon emissions? Posted: 03 Nov 2017 04:22 AM PDT submitted by /u/redditvsmedia [link] [comments]

What determines how a drug is administered (e.g. orally, anally, injected)? Posted: 02 Nov 2017 08:44 PM PDT submitted by /u/Notoriousley [link] [comments]

Why does an oil/soap film look colored due to interference when everyday light is not coherent? Posted: 03 Nov 2017 01:55 AM PDT submitted by /u/rusty_ballsack_42 [link] [comments]

Quarks can change flavours but can they change colour? Posted: 02 Nov 2017 08:18 PM PDT I know that weak interactions can change quarks' flavour but now I'm wondering can the weak force or any force that is applied to it, can it change the quarks colour? Because in QCD it says that the total colour of a particle has to be white so all its quarks have to, once 'combined', equal white but could a force change one of the colours and therefore turn the whole particle from white to another colour and therefore break the particle apart? if that makes any sense? I hope someone understands me because I think I explained my reasoning poorly! Thanks a lot in advance! submitted by /u/JackTalle [link] [comments]

Is there a limit to how long a radio wave can be? Would extremely long waves be of any use? Posted: 02 Nov 2017 06:54 PM PDT submitted by /u/ironfist221 [link] [comments]

What's the maximum height a fly or a mosquito can reach? Posted: 02 Nov 2017 02:33 PM PDT I mean flying of course! Is there a limit? How high is that? Why? submitted by /u/Il_biga [link] [comments]

Does the severity of an anaphylactic response increase with each exposure to an allergen? Posted: 02 Nov 2017 06:17 PM PDT submitted by /u/nowyouseemenowyoudo2 [link] [comments]

Why do our bones regenerate? Posted: 02 Nov 2017 04:35 PM PDT In the wild, animals don't have the option to set their bones back into place. So why have our bodies evolved to bother allocating energy into bone regeneration? submitted by /u/Robesc [link] [comments]

Can I use two point sources to accurately simulate a bar magnet? Posted: 02 Nov 2017 04:27 PM PDT I'm trying to write a magnetic simulator in a video game engine that lets magnets attract and repel each other in zero gravity. So far, in order to avoid integrating over the length of the magnets, I have the code written to represent bar magnets as two different 'monopoles' (a North and a South) at a fixed distance from each other. It's delightful to watch these pairs spin around, repel and attract each other, but I really am not sure if this is an accurate approximation of how this would really play out in space with bar magnets... Am I accurate as is? Or will I need to start over with full bar integration? submitted by /u/Tycho234 [link] [comments]

If a photon is emitted and absorbed by high-level and low-level electrons respectively, is it stored in the electron and drawn out or does it just pop into existence? If it just pops into existence, where does that energy come from? Posted: 03 Nov 2017 01:19 AM PDT I was reading a book by Kauffmann titled Discovering the Universe in which he states that high-level electrons create photons and low-level electrons absorb them. I was wondering if photons exist independently from electrons or if they are part of them, and if they are independent where does their energy come from? submitted by /u/Azazel-IMX [link] [comments]

Why does staring at a fixed point in a dark room create the illusion of blindness? Posted: 02 Nov 2017 07:20 PM PDT Staring at a fixed object in a mostly dark room will lead to the object fading out slowly in your field of view. Why does vision become impaired when the point of reference remains stagnant? Why does the autokinetic effect on the eyes work in well lit areas, but not as well in dark areas? submitted by /u/Josiah425 [link] [comments]

Would we be able to differentiate between an engineered biological weapon and a natural super-virulent flu? Posted: 02 Nov 2017 11:09 AM PDT Let's suppose some country uses modern gene editing techniques to engineer a new hyper-virulent, deadly flu virus. Would scientists be able to positively identify genetic engineering within the virus, or would it be indistinguishable from a naturally mutant virus? I realize that the flu isn't necessarily the best example of a biological weapon, but it might be able to "slip under the radar" more successfully than antibiotic resistant plague. submitted by /u/siliconlife [link] [comments]

Gravity on an ellipsoid? Posted: 02 Nov 2017 08:54 PM PDT Say you're walking around an elliptical planet. It's a magical planet, and isn't rotating, yet retains its elliptical shape. Give it a mass and mean radius equal to earth. Here are my questions, based on this diagram: 1) Which point has a stronger gravitational pull towards the center, point A or point B? Point A is closer to the center of mass, but B has more mass directly beneath it. Are the forces equal for this reason? Or does the inverse square law make point A the winner? 2) What is the magnitude and direction of point C's gravitational pull relative to point A and B? What would it be like to be standing on this point? 3) How do these questions change as the eccentricity of the ellipse increases/decreases? Thanks! submitted by /u/IIIBRaSSIII [link] [comments]

What is actually happening when helium affects the sound of our voice? Posted: 02 Nov 2017 06:56 PM PDT submitted by /u/isthistaken- [link] [comments]

Why do songs get stuck in our head? Posted: 02 Nov 2017 01:53 PM PDT submitted by /u/jmcn99 [link] [comments]

Why does faster than light travel equal time travel? Posted: 03 Nov 2017 02:54 AM PDT Hello! I'm an aspiring novelist currently writing a science fiction piece. I'm a stickler for scientific accuracy, thus when implementing FTL-travel in my story, I'm trying to wrap my head around everything to get stuff accurate. Now. I've read a whole bunch on the topic, and invariably, everyone says that FTL equals the possibility for time travel. I can parrot the explanations given to me, but that doesnt mean I understand WHY. In a way, I guess the title could be "Why isnt there any cosmological clock?" The way I've had it explained to me in the past is the following. If I'm writing a letter and send this letter using a faster-than-light mailman from Earth to Mars it would arrive at Mars before a person on Mars, using a superstronk telescope would be able to see me write this letter. Thus, it is explained, that if the person at Mars recieves the letter, writes a reply and sends it back to me using the same FTL-mailman, it would arrive at Earth before I started writing the first letter in the first place. The thing is.. I dont get why. Take the star Betelgeuse for example. We know its gonna go supernova within the next million years or so. For all we know, it already has, the light from said supernova just hasnt reached us yet. However, when we do recieve the light from Betelgeuse, we can say that the supernova happened 642 years ago (the distance between Betelgeuse and Sol is 642ly). The way I want to understand it, in an entirely hypothetical scenario, if the light from Betelgeuse had travelled at 3c, it would just have reached us 428 years faster, but we could still say that it happened 214 years ago. If we then had a ginormous mirror and reflected that light back, at the same speed it had, it would arrive at Betelgeuse 428 years after the supernova happened local time, or 214 years before light travelling at c would have reached us on Earth. But people have told me, using the mailmans example, this would somehow constitute time travel and the light would arrive at Betelgeuse before the supernova. Which makes no sense. Can you please explain to me what I'm not understanding? submitted by /u/WhenTheGodsSleep [link] [comments]

Does putting alcohol into a fancy looking decanter necessarily make it taste better? Posted: 02 Nov 2017 02:18 PM PDT submitted by /u/Vir_Maximus [link] [comments]

How do different nuclear bombs fuse or fizz materials? Posted: 02 Nov 2017 09:38 PM PDT I know that hydrogen bombs fuse hydrogen into helium and that fission bombs start a chain reaction involving uranium, but how do these bombs trigger quickly enough to cause detonation? What is used to compress the hydrogen in hydrogen bombs, and what gets the uranium fission going so much faster than in a reactor? If anyone knows the principle behind a neutrino bomb, I am also interested in this. submitted by /u/RogerGodzilla99 [link] [comments]

In what cases would you want a leading vs. a lagging power factor and vice versa? Posted: 02 Nov 2017 09:37 PM PDT Started learning some power electronics and i'm trying to get a better grip on leading vs lagging currents/voltages and if it is ever desirable. In general I assume you can play around with capacitors and inductors to adjust the real power from a system but would there be a reason why you would want to purposely lag a voltage or current? submitted by /u/pjcircle [link] [comments]

Considering the relative nature of velocity, are momentum and inertia the same thing? Posted: 02 Nov 2017 07:18 PM PDT As far as I understand, the difference between momentum and inertia is that momentum involves velocity, inertia doesn't. If the measure of an objects velocity can be altered depending on the frame of reference, it would make sense that it's influence on momentum could be neglected. To put it another way: we can change an objects measure of velocity to whatever value we want by changing the frame of reference we measure against. So, can't we just neglect whatever influence velocity has on momentum by simply changing the frame of reference to one that facilitates such a response? submitted by /u/mooseman77 [link] [comments]

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