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askscience	Almost no one actually lives above the artic circle or in the southern hemisphere. 85% of the planet lives within the band that would make you instantly travel between 500 and 1000 mph if the earth stopped turning. So not literally _just_ people at the poles, but you'd have to be pretty close to the poles for you to have a chance. Even at the 80th parallel (the pole is 90, equator is 0), you'd be moving at about 180 mph, which is easily enough to kill you. Here's a cool calculator. https://www.vcalc.com/wiki/MichaelBartmess/Rotational+Speed+at+Latitude
askscience	Your highest altitude will be whatever it was when you start. I'm not sure exactly how to calculate it, but one crude method might be to think about the horizon: The line between a point on the horizon and your eye is a tangent to the surface of the Earth (theoretically - there's air refraction and land masses and other nonsense we'll ignore). Rounding, quite a bit, if you assume you're two meters from the surface, the horizon is about 5 km away. So over the course of 5 km, the surface falls away by two meters. Or, in other words, to maintain or gain altitude, you'll need to cover those 5 km in less time than it takes for an object to fall two meters. The bad news is - that's about a half a second, and you'll only make it 250 meters or so in that time.
askscience	Which thing? If the earth stopped spinning, it would only have a tiny effect on the Moon, since the tides would go off. Measurable, perhaps, but not significant. Then, if the Earth stopped in its orbit around the Sun? Not for any reason I can think of. The moon would stay more or less in its current orbit around the sun, which is to say, our orbit around the sun. Just without the wobbles of being in orbit around Earth. The Moon's orbital velocity around the Earth is 1 km/s, and the Earth/Moon system is orbiting the sun around 30 km/s. So depending on when it happened, it would only shift between 29 and 31 km/s. Might get a little more elliptical, but it wouldn't be far off.
askscience	Yeah, but what is the axle connected to? Hypotheticals are only interesting or meaningful if they specify things like that. Otherwise it's just imagine whatever you want and you can't really say anything specific. If the axle is connected to the core, very different things happen. It it's attached to everything through the axis, how thick is it? If it's only a few miles thick it probably wouldn't affect people at the equator that much or slow rotation, but it would certainly tear up an area near the poles, probably making some kind of lava-lubricated bearing.
askscience	Considering you are going nowhere near orbital velocity, you will fall faster than the tangent moves away from the surface. So to correct my earlier statement, you would gain zero altitude precisely. If you were on a huge flat frictionless skating rink on skates (pointed East), you would just start moving really fast. You would be slightly lighter, but wouldn't leave the ground. Edit: More info: Orbital speed is higher the closer you are to earth. The ISS orbits at about 7.6km/s. The moon orbits at 1km/s. So orbital speed at the surface is somewhere higher than the ISS. But the Earth turns at most 0.47km/s, which is how fast you'll be moving if the Earth stops. Since you're moving tangent to the surface, you have to move faster than the ISS just to maintain your altitude (say, you pull up your legs when the Earth stops). To gain any altitude, you have to go faster than that.
askscience	> Your highest altitude will be whatever it was when you start. I don't think so - imagine going with a really high (or infinite) speed. You're constantly moving away from earth then and thus constantly increasing your altitude. But then imagine going a really really slow speed like 5 km/h, then either you are right and you basically just drop to the ground, or there is like a super tiny short moment right after the start where you are just ever so slightly higher than at the start because of the curvature of the earth. I don't know which hypothesis is true and it would really be awesome if someone with a nice physics background could solve this using some formulas. (which is not too easy since the direction and even strength of the gravitational force is constantly changing as you are moving). I might try some numerical approximations with a small script later... :D
askscience	The poles are rotating. And very slowly, since they make one full turn every (about) 24 hours. Picture standing on your toes and turning around at this rate and you'll realize anyone at the poles probably wouldn't even notice. Alternately, think of standing at the very center of a merry-go-round; if it's going fast and suddenly stops, you'd be fine (maybe stagger a bit, because it spins more than once every 24 hours), but anyone standing near the rim would probably fall over. The further you are from the center the faster your speed changes, and the Earth is very big.
askscience	There’s plenty of tidal resonances that are theoretically possible! 5:3 is another relatively common resonance. A 2:1 resonance is actually less stable than a 3:2 resonance so a planet would never go from 3:2 to 2:1, but a 1:1 resonance is almost always favored over 3:2. In general there are two main causes of a planet “settling” into a 3:2 resonance, instead of slowing all the way to 1:1. This can happen if the planet has a relatively massive permanent asymmetrical deformation, or if the planet has a high orbital eccentricity. In the first case: the planet will likely stay in a 3:2 resonance without shifting to 1:1 since the “stability” of the 3:2 resonance depends on the deformation of the planet which will likely never change. In the second case, however, highly eccentric orbits will tend to circularize over time meaning that the 3:2 resonance will become less stable and the planet will eventually begin to settle into a 1:1 resonance. When talking about the solar system, however, this is completely useless information. The circularization timescales for terrestrial planets are generally much much longer than the predicted lifetime of the sun, so mercury will likely never slow to 1:1. This information does, however, become useful when talking about red dwarf systems! Since red dwarfs can theoretically live to be hundreds of billions if not trillions of years old then there’s plenty of time for eccentric orbits to circularize! I would share some math, and go a bit more in-depth, but I’m currently in the process of publishing a paper on this exact subject!! So there’s only so much I can say.
askscience	Follow up to this, in a much broader viewpoint, the earth is moving around the sun and the whole solar system is moving around the center of the galaxy. If all forces are assumed to be tangentially perpendicular, in how many reference frames would the earth need to stop movement in to overcome that exit velocity? First: rotation, not enough Second: speed with respect to mars or Jupiter around the sun. Third: velocity with respect to sun Fourth: velocity of sun (and therefore by massive assumption the rest of the solar system) compared to a nearby solar system Fifth: velocity with respect to the actual center of the galaxy
askscience	If Earth's orbit around the sun were suddenly stopped, however, objects on earth would more than achieve escape velocity relative to Earth's surface: Earth's orbit around the sun is almost 30 km/s, 2.73 times escape velocity. I'd guess people on the face of the planet pointed in the direction of our orbit would simply be ejected out of the atmosphere assuming there's nothing over their heads, everyone on the opposite side of the planet would simply be pulverized into whatever is under their feet, and the people on the "sides" would be a crapshoot depending on where they're standing and what's in their way.
askscience	The question was "if the Earth stops moving"... as in the planet. The responses have been discussing humans and buildings and water and everything else. > drawing arbitrary lines like "the Earth stops moving but all the people on it don't" The premise is that suddenly, there's no more spin. The earth's rotation is abruptly halted. Ergo, it stops moving... and like the bus that suddenly slams on its breaks, everything inside it suddenly experiences a big acceleration. That's physics. The only way for everything to stop at once (the planet, the people, etc) is if it's really gradual...
askscience	Does the explanation also account for the massive Tsunami's that would also be generated? Oceans which were moving at Mach 1.5 (approximate) prior to the stop would unleash torrents of water. Normal tsunami's move around Mach 0.7. The North Pole would also likely become the World's largest iceberg. As mentioned, storms would also be caused of a magnitude that would make a category five hurricane seem like a gentle breeze. I short, the only thing that may survive is some of the sea life, and even that is open to speculation.
askscience	Compared to whatever absurd speeds were mentioned before? Hell yeah. My car can hit 150 top speed, so if the Earth were to suddenly stop spinning and I was at top speed going the right direction, it would essentially be like getting in a collision at 30mph. Much more manageable than being instantly hurled at the nearest wall or object at Mach 1. Then again, if the Earth stopped spinning, I suspect the lack of atmosphere would be a much bigger problem anyway.
askscience	Well it depends on what stops really. If you take the idea that everything solid or semi solid connected to the earth's core stop at once, then it should not move. However, if only the core or mantle stop moving... the crust might just peel like a potato all over the place. If only the core stops, it will still be a world ending scenario, but a tad slower I presume. The mantle inertia might even transfer some of its speed back to the core and make it somewhat move again.
askscience	I figure most people will die in milliseconds. A few people who happen to be on high ground and have a clear line of sight to the east might survive for seconds as they fly through the air. People in airplanes at cruising altitudes might have a minute before the turbulence breaks up their airplanes. People at the south pole would probably avoid a quick death, but I suspect that debris-filled winds would get them in under an hour. Even people on the ISS would be doomed one way or another--the ISS is in a relatively low orbit and it's conceivable that the atmosphere would be disturbed enough to increase drag and bring it down in days or weeks. Even if that didn't happen, they would die from a lack of food/water/air and no where safe to land in under a year.
askscience	You wouldn't get smeared, at first. Think about any rotating sphere that is covered in liquid, regardless of gravity, objects in motion tend to stay in motion unless acted upon by an outside force. Water will fling right off a rotating sphere. Putting it in context, given that gravity is 9.8m/s/s and the Earth would come to a complete stop from 447 m/s, you will be imparted with nearly 46 G's of force and you will break from the Earth's gravity. You would effectively be launched due East. Now, everything else would be moving with you, the crust of the Earth included. It seems more likely that the entire Earth would in a sense behave as if it 'exploded' and then if gravity was still having an effect, when everything lands, things would get 'smeared'. No need to be on a building, you gon fly, and then ded.
askscience	It depends how deep the bunker is. The closer it is to the Earth's core, the lower its rotational momentum, and therefore the less affected its occupants will be by the cessation of the Earth's spinning. The occupants would probably melt within a fraction of a second at that proximity to the core, but since the spin is ceasing instantaneously, maybe a fraction of a second is all you need to say you survived! Just be sure to say it quickly.
askscience	Given the rate at which the rocks around you heat up and the issues of pressure turning oxygen poisonous, you’re not getting out of the crust, much less near the core. Unsurprisingly, there is an XKCD for that: https://what-if.xkcd.com/135/ The deepest hole on Earth is a bit over 12 km deep, which is a literal rounding error compared to the radius of the Earth. The equatorial radius is about 22 km larger than the polar radius, which is still just a few tenths of a percent of the total. That borehole is only about as wide as an open hand, too: https://en.wikipedia.org/wiki/Kola_Superdeep_Borehole Even if you dealt with the pressure and temperature within your bunker, as the rock surrounding it heats up and the weight of the rock above increases it will start to behave like a plastic and squeeze your bunker like a pimple. Ocean pressure is crazy, but rocks are denser than water.
askscience	I could definitely be wrong but I believe the air wouldn't immediately react to the sudden change in earth rotation speed due to newton's 1st law . Have you ever tried to rotate a glass of ice water to get the straw closer to you; only find that the straw barely moves in the direction you turned it. I thing something similar to the following video would occur would the balloon pilot if the earth suddenly changed speed. https://youtu.be/HH4zU76cffY
askscience	Satellite dish is needed only for high bandwidth needed for video transmission which is encoded with minimal error correction so that you can pack whole video signals into the bandwidth. You need the dish to receive such video transmission because you want to receive every bit of it clearly. GPS signal is just text. They can pack hell lots of error corrections and repetitions into the bandwidth. The GPS chip inside your phone use such error corrections to compensate for low signal power. This is all possible thanks to the ultra-low noise amplification transistors inside the GPS chip.
askscience	To triangulate, you have to know the position of the satellites with a very high accuracy. Satellites drift all the time, so you need an updated (minutes or hours) position for each one. The satellites themselves broadcast that data, but it's kinda slow, and your device can't tell you your position until it gets all the data from each satellite it wants to use. This is how all GPS units originally worked, and basic hand-helds still do. But, for devices connected to the internet (like a cellphone) you can download updated, precise location data for every satellite in the GPS system, very very quickly. Then you can ignore the slow positioning data and just pick up the time signal. End result is your device can report your position within 2-3 seconds instead of 30-40 seconds.
askscience	> that got me interested, please elaborate Captain? At least in the group of people I worked with, we tended to refer to satellites as "birds" so finding the satellite was basically "acquiring the bird" and uplinking was "squirting the bird". In terms of what the GPS satellites transmit, they transmit a timing signal that allows for the locating function. They also transmit the almanac of the coarse orbital data for all the satellites as well as the fine ephemeris for itself. This is why if you take a GPS receiver to a new location (a few hundred km from the last place it was powered on) or turn it on after a few weeks off, it takes forever to acquire its location. What it's doing is running a cold start procedure, where it searches all possible satellite codes until it locks on, then it has to wait to download the almanac (which takes 12 minutes), and then get the fine ephemeris data for all the satellites.
askscience	No, it's not the same. Sleep is a complex neurological state that we've only recently begun to understand where, while there is no alert consciousness, the brain is still cycling through a series of neurological activity (the chief of which, at least as far as day to day relevance goes, is memory reorginization and conversion of the day's memories and information to patterns more reliable for retrieval) as well as monitoring for extreme inputs from sensory capabilities (ie loud sounds or sudden body movements will awaken the sleeper). Loss of consciousness from lack of oxygen or through the use of psychoactive substances is a different mechanism that involves actually shutting down gross neuronal activity. In the case of oxygen deprivation, you're literally starving the brain of oxygen, forcing it to shut down processes in a survival-dependent manner. Brains take a lot of energy, but someone in a hypoxic environment can still survive if there is enough oxygen to maintain cardiac and respiratory function (though how long and at what cost are definitely things to consider). Your entire brain goes through neurological rhythms while asleep. If you're inducing loss of consciousness, the resources necessary for those rhythms to occur are being cut off. I'm not the biggest fan of brains-as-computers analogies, but I'll make a simple one here: You can shut down a computer by yanking the cord out of the wall, or by shutting it down through the OS. It's off either way, but one of those ways can cause the computer to malfunction depending on the state it was in when the shutdown occurred, and how often that method of shutdown is employed.
askscience	Medications release chemicals into the brain that affect the brains natural chemistry to what it would be when falling asleep naturally, essentially prodding it along. However as with anything changing brain chemistry it becomes harder to recover the more the medication is used and the brain would eventually become dependent on it. The chemical is no longer released by the brain as it has learned that it will be administered via foreign sources (the pill/tablet). So long term use can be very harmful.
askscience	Also, being knocked unconscious via traumatic brain injury is yet different from fainting (due to low blood pressure, hypoxia, etc.). They're also dangerous in different ways. As long as the issue causing the hypoxia or low blood pressure is fixed in a timely manner, fainting is unlikely to cause any permanent damage (unless you hit your head on something). A traumatic brain injury is, in general terms, at least partially permanent (the injury persists, brain can learn to work around it).
askscience	Just so you know, you lose zero, and I mean ZERO time while knocked out. It's why so many fighters seemed confused when they come to. It's like, hey I was just punching you two thousandths of a second ago, why am I looking at you from the mat?? The experienced fighters will recognize the confusion as the sign they were knocked out, since there is no actual like, remembered trigger? Either way it's something I've always found interesting.
askscience	Analogies with computers work in reverse too. We were taught modern computer architecture by comparing it to the function of the brain. In reality though, the brain is more similar to a massive network of computers than a single one. This is even more apparent in a recent experiment where researchers used 80000+ processors over 40 minutes of real-time to simulate the biological processing of ~1% of the brain over one second. Apparently, in a real brain there are as many neurons as there are stars in our galaxy and each of those neurons are "networked with" about 10000 others. The complexity and sophistication of a human brain is just mind-boggling.
askscience	I’d just clarify that narcotics and alcohol are not medications do not necessarily follow this mechanism. A glass of wine before bed more likely functions by relaxing or depressing other stress stimuli that are keeping you awake: literally inhibiting an inhibitor to normal sleep function. In moderation, this should be safe and possibly even healthy, in that sleep is critical to normal function and activates repair mechanisms in the body. However, drinking until you pass out can be more akin to a concussion than normal sleep.
askscience	my oral surgeon said they actually stop the drip early, before they have the last couple stitches in, so it's easier to wake up. as I was waking up I faintly recall someone saying "go back to sleep" so I happily obliged and drifted off for another couple minutes. no idea if I woke up 2 minutes early or 20, though. but by the time they wanted me out of the chair and over to the recovery area I was mostly mentally all there again, I remember it all pretty clearly after being told it was time to get up. I did remember totally wanting to sleep for an hour or so though. I dozed a bit in the recovery area but I'm pretty sure that was more like normal sleep because it did actually feel like time passed. but I have absolutely no memory of anyone shoving 6 cotton balls in my mouth, but there they were, all wedged up in those holes in my jaw.
askscience	my oral surgeon said they actually stop the drip early, before they have the last couple stitches in, so it's easier to wake up. as I was waking up I faintly recall someone saying "go back to sleep" so I happily obliged and drifted off for another couple minutes. no idea if I woke up 2 minutes early or 20, though. but by the time they wanted me out of the chair and over to the recovery area I was mostly mentally all there again, I remember it all pretty clearly after being told it was time to get up. I did remember totally wanting to sleep for an hour or so though. I dozed a bit in the recovery area but I'm pretty sure that was more like normal sleep because it did actually feel like time passed. but I have absolutely no memory of anyone shoving 6 cotton balls in my mouth, but there they were, all wedged up in those holes in my jaw.
askscience	my oral surgeon said they actually stop the drip early, before they have the last couple stitches in, so it's easier to wake up. as I was waking up I faintly recall someone saying "go back to sleep" so I happily obliged and drifted off for another couple minutes. no idea if I woke up 2 minutes early or 20, though. but by the time they wanted me out of the chair and over to the recovery area I was mostly mentally all there again, I remember it all pretty clearly after being told it was time to get up. I did remember totally wanting to sleep for an hour or so though. I dozed a bit in the recovery area but I'm pretty sure that was more like normal sleep because it did actually feel like time passed. but I have absolutely no memory of anyone shoving 6 cotton balls in my mouth, but there they were, all wedged up in those holes in my jaw.
askscience	Absolutely true. I actually started writing about this, but it was running longer than my original comment. Alcohol has one of the [worst safety margins of any recreational drugs. ](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4311234/#!po=25.0000) There are many methodologies to estimate this, but in general the Therapeutic Index is [the ratio of the toxic dose over the therapeutic (or recreational) dose. ](https://en.m.wikipedia.org/wiki/Therapeutic_index#Safety_ratio) Toxicity is generally estimated as lethality in 1% of the population. Alcohol, heroin, cocain, and nicotine come in <=10. Most drugs are 10-100. THC/LSD are around 1000. higher is safer (lol). The small ratio strongly implies that toxic effects (i.e. sleep impairment) have already started by the time you start feeling any effect. Definitely by the time you’ve got a buzz going. On a population level (availability vs. toxicity), alcohol is the [most dangerous recreational drug](http://bfy.tw/Jmp7) by an order of magnitude. But I’m not going to try to nanny redit. A glass of wine 1-2x a week is likely cool for most people who would follow conservative medical advice on reddit. As a public service, i will provide the best scientific evidence available from a quick check of the primary biomedical literature: ___ Alcohol Clin Exp Res. 2013 Apr;37(4):539-49. doi: 10.1111/acer.12006. Epub 2013 Jan 24. [Alcohol and sleep I: effects on normal sleep.](https://www.ncbi.nlm.nih.gov/pubmed/23347102) Ebrahim IO(1), Shapiro CM, Williams AJ, Fenwick PB. Author information: (1)London Sleep Centre-Neuropsychiatry, London, United Kingdom. info@londonsleepcentre.com This review provides a qualitative assessment of all known scientific studies on the impact of alcohol ingestion on nocturnal sleep in healthy volunteers. At all dosages, alcohol causes a reduction in sleep onset latency, a more consolidated first half sleep and an increase in sleep disruption in the second half of sleep. The effects on rapid eye movement (REM) sleep in the first half of sleep appear to be dose related with low and moderate doses showing no clear trend on REM sleep in the first half of the night whereas at high doses, REM sleep reduction in the first part of sleep is significant. Total night REM sleep percentage is decreased in the majority of studies at moderate and high doses with no clear trend apparent at low doses. The onset of the first REM sleep period is significantly delayed at all doses and appears to be the most recognizable effect of alcohol on REM sleep followed by the reduction in total night REM sleep. The majority of studies, across dose, age and gender, confirm an increase in slow wave sleep (SWS) in the first half of the night relative to baseline values. The impact of alcohol on SWS in the first half of night appears to be more robust than the effect on REM sleep and does not appear to be an epiphenomenon REM sleep reduction. Total night SWS is increased at high alcohol doses across gender and age groups. Copyright © 2013 by the Research Society on Alcoholism. DOI: 10.1111/acer.12006 PMID: 23347102 [Indexed for MEDLINE]
askscience	Yep. Had my wisdom teeth removed and had to be sedated for about an hour. Last thing I remember was them putting the mask on me. Next thing I remember was them taking off the mask and me thinking they were just readjusting it and asking when they were going to start because I was really nervous. Was shocked to find out they were all done. Was also in a car accident several years ago. Car had structural damage and I was able to walk away with a bad case of whiplash, so it wasn’t a horrible accident, thankfully. I was knocked out, though. I don’t even remember getting hit, I just remember being stopped in traffic and then hearing this loud, godawful sound. Next “second”, I was wondering why my headband had fallen off and was on my face, the doors for the storage under my car stereo were open, why my car was halfway in the other lane at an angle, and why there was a woman with a very worried look knocking on my car window. I have no idea how long I was out and it took me a minute to realize that I had been hit. Pretty scary shit.
askscience	Yep. Had my wisdom teeth removed and had to be sedated for about an hour. Last thing I remember was them putting the mask on me. Next thing I remember was them taking off the mask and me thinking they were just readjusting it and asking when they were going to start because I was really nervous. Was shocked to find out they were all done. Was also in a car accident several years ago. Car had structural damage and I was able to walk away with a bad case of whiplash, so it wasn’t a horrible accident, thankfully. I was knocked out, though. I don’t even remember getting hit, I just remember being stopped in traffic and then hearing this loud, godawful sound. Next “second”, I was wondering why my headband had fallen off and was on my face, the doors for the storage under my car stereo were open, why my car was halfway in the other lane at an angle, and why there was a woman with a very worried look knocking on my car window. I have no idea how long I was out and it took me a minute to realize that I had been hit. Pretty scary shit.
askscience	Yep. Had my wisdom teeth removed and had to be sedated for about an hour. Last thing I remember was them putting the mask on me. Next thing I remember was them taking off the mask and me thinking they were just readjusting it and asking when they were going to start because I was really nervous. Was shocked to find out they were all done. Was also in a car accident several years ago. Car had structural damage and I was able to walk away with a bad case of whiplash, so it wasn’t a horrible accident, thankfully. I was knocked out, though. I don’t even remember getting hit, I just remember being stopped in traffic and then hearing this loud, godawful sound. Next “second”, I was wondering why my headband had fallen off and was on my face, the doors for the storage under my car stereo were open, why my car was halfway in the other lane at an angle, and why there was a woman with a very worried look knocking on my car window. I have no idea how long I was out and it took me a minute to realize that I had been hit. Pretty scary shit.
askscience	Yep. Had my wisdom teeth removed and had to be sedated for about an hour. Last thing I remember was them putting the mask on me. Next thing I remember was them taking off the mask and me thinking they were just readjusting it and asking when they were going to start because I was really nervous. Was shocked to find out they were all done. Was also in a car accident several years ago. Car had structural damage and I was able to walk away with a bad case of whiplash, so it wasn’t a horrible accident, thankfully. I was knocked out, though. I don’t even remember getting hit, I just remember being stopped in traffic and then hearing this loud, godawful sound. Next “second”, I was wondering why my headband had fallen off and was on my face, the doors for the storage under my car stereo were open, why my car was halfway in the other lane at an angle, and why there was a woman with a very worried look knocking on my car window. I have no idea how long I was out and it took me a minute to realize that I had been hit. Pretty scary shit.
askscience	Reddit apparently lost a long comment I just wrote about alcohol’s terrible [margin of safety](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4311234/#!po=25.0000), where I broadly agree about balancing relaxation vs. REM interference. It turns out a [recent review paper](https://www.ncbi.nlm.nih.gov/pubmed/23347102) found that 1 drink seems OK. 2-4 had less REM% but more sleep overall. Not good, but not as bad as I’d have expected. You are over generalizing across a huge range of types of narcotics, especially with regards to dosage. I doubt that the effects on sleep are well established for many drugs simply because almost all drug studies are effectively banned in humans and bureaucratically difficult even in animals. Results for alcohol are mixed even with a $500 million yearly budget for NIAAA. As one counterexample, a [recent review of cannibis and sleep](https://www.ncbi.nlm.nih.gov/pubmed/28349316) suggests that high CBD strains may actually promote REM sleep. I’m not suggesting drugs are great for sleep or anything, merely advocating that we stick to scientific answers here.
askscience	I've passed out from blood loss. It was my final exams week. Went a night with very little sleep. Skipped lunch and breakfast except for a coffee to study/review. Had a friend convince me to donate blood. I lied to the doctor that was checking my blood and doing the test questions when he asked stuff like, "Did you get plenty of sleep? Eat a big meal? Drink lots of fluids today?" Shortly after the donation process started...my attendant left to go do something so I was left unattended. At some point I was unconscious and then suddenly woke up to the attendant pressing on my chest really hard with a big block of ice. It seemed like an instant but it was literally the greatest feeling in my life. Like my brain was instantly refreshed, clear, and charged to 100%. I doubt you can get anywhere near that feeling without using drugs or being put into the same state I was in. The Doctor had even asked me if I experienced the feeling. She mentioned that it feels like the greatest night of sleep in your life.
askscience	Your sleep theory is just one of many theories on what happens in our brains during sleep! We can measure the stages of sleep and record them, but as to what is going on in there, there are some other theories as well! Some theorists claim its a time where the neurons in the brain randomely fire! Sleep is so interesting. And its interesting that we force ourselves into unnatural sleep patterns to accomodate for our 9-5 work days of productivity!
askscience	Very interesting. Does this mean that when you pass out due to drugs or alcohol, you are not entering a state of rest that the brain needs to continue functioning properly? Lack of sleep can cause all kind of issues (hallucinations, impaired cognitive function, etc)- does passing out from intoxication cause you to "lose sleep" and make the situation worse, or is it just the damage cause by the substances themselves and their effect on the brain?
askscience	Alcohol is a poor choice for (quality) sleep induction for a variety of reasons but I would note that there's lots of brain chemistry that inhibits the chemicals that inhibit sleep onset. In some senses, sleep could be seen as the normal state! I guess all I mean there is that something that causes a certain action and something that inhibits the things that normally inhibits that action are functionally similar and not at all uncommon. We see this everywhere from muscular triggering to sensory actuation.
askscience	If you fainted from low blood pressure in the brain, that would be enough to blank out your memories of actually falling to the ground. I've tried this too once, stood up quickly and everything went grey, and next thing I knew I was face down on the floor. I didn't really hit my head apparently, judging from the lack of pain, but the moment between standing up and being on the floor never registered. A friend of mine was in the room and he said I was only out for a second or two, so I think it was equivalent to being choked out rather than being knocked out by a hit to the head. Watch some MMA knockouts vs choke outs. Getting choked, you're fine a few seconds after being let go. Getting knocked out, you're usually confused and groggy for a while after.
askscience	> you lose zero, and I mean ZERO time while knocked out wait... that's gotta be a typo, right? You lose more than zero time when you're knocked out - you lose the time you spent knocked out, which is to say, you don't experience (or remember experiencing) the time you lost while knocked out, and that length of time is more than zero. right? so you don't lose zero time while knocked out. You lose more than zero, and I mean MORE THAN ZERO time while knocked out. Right?
askscience	The brain more or less floats in a water balloon. It can resist a lot of motion, but it can't stop it entirely. Any severe enough change in motion that can cause a concussion will have the possibility of knocking you unconscious when the brain hits the skull wall. That's why the classic "hit to the jaw" is a knock out button, it whips your head back and the brain can't get out of the way fast enough. &#x200B; I think it's the neural overload that comes with it being stimulated by a physical shock.
askscience	They're just too simplistic most of the time and more importantly, they often can't be extrapolated. Quick example off-hand: individual parts of the brain can often be repurposed and used to compensate for damaged brain tissue - if part of your CPU, HDD, RAM or GPU is fried, the computer probably doesn't work at all. They're okay to quickly elucidate confined and simple concepts, but if you try to extrapolate them or dive deeper they often fall apart. They're fundamentally different systems, but they're pretty similar on the surface and the public has at least basic familiarity with them, which is why they're not entirely worthless, despite the predisposition to be misleading.
askscience	I'd say a better analogy is suspending or hibernating the computer versus unplugging it from the wall. When you suspend/hibernate the computer, it's still on, the state is saved (in RAM or on disk respectively), and it's polling for input (keyboard, wake on lan, etc.). This is fairly similar to our sleep states (hence why suspend is usually called "sleep") in that the computer is still on and easily woken in case of "extreme" event like a keypress. Unplugging a computer prevents it from being woken at all; not even pressing the power button from an off state can turn it on. Filesystem defragmentation is something else entirely and has to do with arranging segments of files sequentially on spinning disk drives for faster/more efficient access. I suppose this could be analogous to the rearrangement of memories, but there's nothing actively preventing you from using the computer during defragmentation (and most filesystems (and anything on a solid state drive) don't require defragmentation anyway; NTFS is the only one I can think of that requires active defragmentation).
askscience	If I look at my subjective experience of my consciousness I dont think I can separate it and alertness, it is in the nature of consciousness to be alert just like it is the nature of light to illumine. How much stuff the light shines upon may vary. Also funnily enough from the subjective point of view of consciousness/alertness it never goes off or comes on, it is ever present and unchanging in its own experience of itself.
askscience	Unfortunately I haven't read too deeply into what gamma-ray bursts can do, aside from complete and utter annihilation ^which ^would ^technically ^stop ^the ^spin, ^amiright? I just know they're produced from some of the most energetic events in the known universe, which in itself can cause physics to go all whoppy-doodle, so it seemed like a plausible assumption to me. Now I wonder how massive an object would have to be, how close, and in what nature the event would have to be to just "overwrite" such spinning on such grand scale... Albeit minute in a cosmic sense, huh? Thank you so much for the reply!\^_\^
askscience	I was thinking that too, but as u/Sideswipe0009 mentioned, the "celestial body passing too close for comfort" - which would be ^I ^think a type of Tidal Disruption Event, but on a much "smaller" scale (also not an expert, just a nosey bugger) - could be the cause behind Venus' inverse rotation compared to Earth's own. I know the occurrence in itself would be a majorly rare phenomenon, if it were to happen in the first place, but just our existence is a one-in-a-can't-think-of-a-number-big-enough occurrence, and the universe is unfathomable in size, so who knows?\^_\^ Thank you for chiming in!
askscience	Made me think of Scholtz's star that passed nearly 50 AU to our sun 700,000 years ago. Now i'm just imagining if it was closer and much bigger. Red dwarfs can be pretty hard to spot, so I don't think its too far of a stretch to wonder if we have had one or several giants that grazed to close long ago. &#x200B; Impact rates on the earth, moon and mars suggest there is no long period perturbers out there like nemesis (last time I read about it anyway) but I don't think that discounts rouge flybys.
askscience	Collision with large celestial body at a perpendicular opposite earth's rotation with a little bit more than the earth's current rotational energy. A similar collision is theoretically responsible for our current rotational speed, and the existence of the moon. To better help understand how destructive this would be: [The asteroid responsible for the KT extinction may have made Earth's crust act like a liquid](https://www.npr.org/sections/thetwo-way/2016/11/22/503013290/scientists-say-dinosaur-killing-asteroid-made-earths-surface-act-like-liquid). [The planetesimal Theia would have called that some "pussy bitch shit" and made the crust liquid for millions of years.](https://upload.wikimedia.org/wikipedia/commons/7/74/Big_Splash_Theia.gif) Don't worry. Something like this cannot currently happen because nothing is big enough in our solar system. Rogue planets aside (which we would detect the gravity of approaching long before it hits), all the really crazy collisions finished up billions of years ago.
askscience	And the most amazing part about it is, even with all our "advanced" detection and monitoring systems we have, we could have a "visitor" fly by through a "void" of our solar system - or even outside of it - and that "visitor" have so much mass that its gravity could nudge us ever-so-slightly towards or away from our star, and utterly wipe us out and we be none the wiser. Well, amazing or terrifying, depends on your outlook.
askscience	The lightning strike has causal effects before we hear it. Star collisions don't have causal effects until we see them. The lightning also has no causal effect on us until we observe it - it isnt meaningful to talk about it existing prior to observation, as it was not part of our causality until then. What about things that happen beyond the cosmic event horizon, where observations will never reach us due to the expansion of space? 'When' did they happen? The danger of saying something happened before you observed it is that 'when' becomes ill-defined for unobservable phenomena, where if events happen when you observe them, a phenomenon you cannot observe simply never occurred in your causality. Time and causality are relative.
askscience	A causal effect cannot give you simultaneity. This is very elementary relativity. Or not even that because Newtonian mechanics tells you the same. The light needs time to reach you in your reference frame, therefore the event you see now happened in the past. > What about things that happen beyond the cosmic event horizon, where observations will never reach us due to the expansion of space? 'When' did they happen? With your approach you couldn't even assign a time to them. Do you think that makes sense? Cosmology makes "now" a bit more difficult, but you can consider the same time since the big bang in reference frames with vanishing dipole moment of the CMB.
askscience	You cannot assign a time to them, either. Anything beyond the CEH is ill-defined in yours - however, if events occur when they causally do, those objects effectively don't exist, as they are not observable. In yours, they will never be observable but still effectively exist, so the time they occur is ill-defined as they are not nor ever will be part of your causal reality. It doesn't make sense to talk about events occurring before they are causal. It doesn't make sense to even consider events that will never be causal. This is basic physics, and I'm unsure why you are dismissing simultaneity. The time events occur differs from observer to observer. In our reference frame, something happens when it is observed. Happening before that is meaningless. You are effectively proposing absolute time... which is bizarre.
askscience	> You cannot assign a time to them, either. I just described how you can. > It doesn't make sense to talk about events occurring before they are causal. It makes sense and it is routinely done. > and I'm unsure why you are dismissing simultaneity. I'm dismissing your misconceptions about it. > You are effectively proposing absolute time... which is bizarre. I'm not. Look, I can help you learn about relativity. But I won't continue this discussion if you keep insisting that your misconceptions have to be true because this is a waste of time. Go read a book about relativity. The first few pages should be sufficient.
askscience	So the short answer is that there is no exact solution to the Einstein field equations involving two black holes (and there probably never will be). This means that we wont know the exact form the geodesics will take. But we can make solid guesses and do numerical calculations. The best source for these considerations I have found is [here](https://arxiv.org/abs/1010.5260). However, this review focuses mainly on the gravitational waves produced by these mergers. It does, however, consider your final question in one of the last sections. In general, the amount of electromagnetic radiation given off will depend on the size of the hole and the presence of an accretion disk or other matter between the holes. Also, this radiation is expected to arrive at the same time as the gravitational waves since they both travel at the speed of light. Any deviation from this would be evidence for some speculative physics theories like de Sitter Relativity or Causal Dynamical Triangulation. Also, keep in mind that since light always travels the same speed it will not be "accelerated" like you mentioned. It can experience red- or blueshift though. Also, we can make some good guesses about the geodesics, and the paths of light, that occur in this system. There will not be any (observable) figure 8s since if it is meaningful to say they occur it would be within the event horizons of the merging black holes EDIT: this is not true, I don't know if there would be any stable photon orbits and what they would look like. Also, a lot would depend on the size of the holes since for supermassive black holes the local curvature outside the event horizon is extremely close to flat. This means that if not for the presence of other matter you would not experience any trauma from being between the two edges of the event horizons, no matter how close they were, and you wouldn’t necessarily see any extreme optical phenomena when you look away from the holes. But from other perspectives or smaller black holes, there would probably be some very weird and extreme gravitational lensing. Light sources behind a single black hole will appear from a distance as an [Einstein Ring](https://en.wikipedia.org/wiki/Einstein_ring). But from behind the merging black holes, they might make an [Einstein Cross](https://en.wikipedia.org/wiki/Einstein_Cross) or even something weirder since the distribution of matter is elongated but in a more interesting way.
askscience	You have to remember that our assumption is that roughly speaking, time and space switch roles beyond the event horizon, in that space becomes unidirectional. But there still must be a geodesic it's just that it's different in the same crazy way that everything else is. The geodesic is no longer a spatial feature, rather it's a temporal feature. And maybe the word anti-geodesic would be more appropriate. Any acceleration just takes you to the singularity in a shorter period of time. The way to survive the longest is by having zero acceleration. So, instead of there being a fastest way from point A to point B, there is only a slowest - the anti-geodesic. The other possible paths would be time dependant rather than space dependant. With the various paths consisting of the non-accelerating path, plus the infinity of other paths that would change your temporal position based on acceleration.
askscience	I'm going to drop you in a deep lake with 300lbs of lead on your back. Anything you do, or any possible momentum you hot the lake with won't matter as far as "will you hit the bottom" but you could try to swim out, or thrash about which would take you along a different path. But there's still a minimum and maximum time to bottom for you, and there's no way you're not hitting the bottom. It's like that. Say an object/particle crosses the event horizon at a perpendicular angle, it's going to make a straight line to the singularity. Say that same object crosses at a large fraction of c on a tangent. It may very well make it around a few times. It still gets to the center eventually, but even a photon at c if it's on a path that crossed the event horizon that path gets to the center. That path just might be 'orbiting' the core 100,000,000 times. The reason you can't get a 'stable' orbit inside the event horizon is you need to be traveling at c exactly tangental to core but any path that meets that criteria would be definition just graze but not cross the horizon.
askscience	That didnt really address my point. That every possible path is directly (as in a straight line) towards the singularity. I didnt say anything about how long it would take. > The other possible paths would be time dependant But is there time inside the horizon? how does causality function inside the horizon, where there is no longer a possibility for causal relations to happen? or any and all causal functions happen at the same time
askscience	We're using words like space and paths, so the assumption was that you were indeed talking about spacetime, which time is inherently a part of. And if we look at the various equations that describe what spacetime beyond the event horizon might look like, then typically the roles are reversed for time and space. So not only would time still exist, but it would be traversable. Causality doesn't depend on time. Causality is a law that applies to spacetime, in that depending on your point of view, cause and effect might appear very different to you compared to a distant observer. But no matter how much you might disagree on duration, length, etc, you will agree that the causal spacetime event proceeded the effected event. How would this look to us beyond the event horizon? Hell if I know. But if we're using the framework of relativity to describe an event horizon, causality doesn't cease to exist. It might be super weird from our point of view, but that's true even outside the event horizon depending on an object's relative motion. And in any case, also remember that an object's worldline doesn't have to be perfectly straight toward the singularity. It just inevitably moves closer to the singularity no matter what its velocity or acceleration is. And even if the paths were perfectly oriented toward the singularity as a rule, two objects that crossed the event horizon at the exact same instant don't have to reach the singularity at the same instant. Thus there is a slowest way to the singularity (which would be the analogue to a geodesic, just with an opposite sign) and infinite "paths" that would cause you to arrive at the singularity at different, earlier moments. The area beyond the event horizon is presumably still curved spacetime just with space becoming time-like and vice versa. It's hard to describe everything up there with words, but if you look at the equations and consider how they apply for us here in "normal" spacetime, then just flip the signs on certain equations, or switch the roles of certain variables and you can begin to imagine what it might be like beyond an event horizon.
askscience	There is not infinite curvature at or within the event horizon. This only occurs at the singularity, and is not a prediction of the theory as much as mathematical evidence that the theory is an effective, but known broken one. The event horizon for a sufficiently large black hole wouldn't even be noticed by an observer falling in - this would break one of the core invariance principles from which GR was derived in the first place.
askscience	Spacetime is a great show, and I've probably seen all of those. I'm also pretty sure they haven't contradicted anything I've said. Here's an article I just found on Cornell's website with one Google search, maybe you'll believe them since they explain things better than I do. Especially the last statement: >If you think about it for a while, you'll be able to come up with loads of strange situations that can happen inside a black hole--but none of them will be logically inconsistent [What happens to spacetime inside a black hole?](http://curious.astro.cornell.edu/about-us/89-the-universe/black-holes-and-quasars/theoretical-questions/455-what-happens-to-spacetime-inside-a-black-hole-intermediate) And an edit: This is the last reply I'm going to make, unless you happen to include the relevant equations that describe what you're talking about.
askscience	I think some of the confusion here is that you are imagining that things become so completely different inside an event horizon. Nothing very special happens from the perspective of someone falling into a blackhole. With a large enough black hole, the tidal effects can be made arbitrarily small, so even somewhat inside the event horizon, locally, nothing would appear amiss. From your perspective time moves forward as normal, and there is causality. The only difference of course is that all causal paths eventually lead to the singularity.
askscience	This mainly goes to show how big a problem shrink-wrapping is in paleoart. Dinosaurs are frequently drawn to look as lean and muscular as possible, almost to the point of having zero fat reserves. Like [this delightful illustration here.](https://wi-images.condecdn.net/image/p0wm8oY6jJw/crop/1620/f/ju_paleoart_p264-265.jpg) The album is from a book called All Yesterdays, which also presents speculative reconstructions of dinosaurs as different from the picture I linked as real animals are from those in the album above.
askscience	Right? I was just thinking that fatty features like breasts and waists and butts or cartilage like noses and ears wouldn't survive as well and might be more guesswork. maybe the tailbone would be more pronounced as a nub rather than totally buried. the nose would be pushed up like a chimp nose. the ears might be pointed, or missing, or the wrong size. the hands might have less webbing and be more bony like the grasping hands of bush babies or other small primates. the feet might have the toes fused more. and the lips and eyes might be all wrong! giant marble eyes with thin little lids, sticking out too far. and big wide lips that go all the way back to where the molars are. it would look terrifying
askscience	I have a feeling you are not at all familiar with Science, let alone paleontology. You can do quite a bit with "just three or 4 bones," if you have [the right bones, and/or teeth](https://www.youtube.com/watch?v=1qW256pUdYg), as the case may be. No one takes "3 or 4 bones" and makes a model of a dinosaur or other animal de novo. Those few bones will have to be strongly linked to some other known creature before they can be used to try to flesh out a model of the individual those bones came from. I'm a research scientist so I know how rigorous is the process to get something published, let alone develop a model that requires very many publications of reproducible data reviewed by skeptical peers before it is seriously considered in your field. I don't expect laypersons to appreciate this process, so I understand the layperson's strongly held skepticism of something they really do not fully understand.
askscience	Yes, it should be noted that every shrink-wrapped animal in that album is a mammal. I'd mostly agree with what you said, but I want to point out some exceptions that in my opinion are significant. I'd argue that there are numerous examples of reptiles that are not at all shrink-wrapped, like the [Argentine tegu](https://bugwoodcloud.org/mura/ECISMA/assets/Image/dirtydozen/tegu/red_tegu.jpg) and the [American alligator](https://i.ytimg.com/vi/Cy2akN2bTX4/maxresdefault.jpg). We do see extreme shrink-wrapping in birds, but this effect is offset by their feathery coverings, so this should be reflected in paleoart as well. I'm using the term shrink-wrapping to describe an actual phenomenon in living organisms, but really the term only applies to how artists depict an animal. I'm not exactly sure what term you'd use to describe a lack of non-boney accoutrements or excessive fat reserves. Also, the prehistoric mammals we depict in paleoart tend to be from the glacial Pleistocene, so naturally they're drawn with lots of fur. Popular depictions of older Cenozoic mammals like this [Hyaenodon](https://vignette.wikia.nocookie.net/cooldinofacts/images/4/45/H._gigas.jpg/revision/latest?cb=20120115130555) and this [Chalicotherium](https://dinosaurworld.net/wp-content/uploads/2016/09/Chalicotherium-2.png) are pretty badly shrink-wrapped.
askscience	Yeah, totally agree. I was just saying it makes sense why early artists who tried to depict these animals did so the way they did. If they are going from just the skeleton, it's very hard to figure out what something actually looks like. Ears, noses, boobs, dicks, anything not from the skeleton is just conjecture. But with more and more info and these better preserved fossils, we can get closer to filling in that gap.
askscience	This book was written and illustrated to show how we revolutionized out thinking of dinosaurs in the last 30 years. It is essentially pointing out how drawing dinosaurs in the Jurassic park or earlier popular styles were terrible in their shrinkwrapping. It is pointing out how wrong our previous media representations have been and demonstration why the whole "But they looked COOLER when I was a kid, I am going to stick to that" mentality can detrimentally effect paleontology as a whole.
askscience	All very good points! I'd like to add another: the energy of photons within the 400-700 nm (ish) range is conveniently on the order of electronic transitions within small organic molecules. Higher energy light (UV, for example) typically has enough energy to start breaking down certain molecules (despite a greater degree of scattering through tissues limiting its depth of penetration), while lower energy light (beyond the infrared range) would not be able to excite the types of molecules in our photosensitive cells (rods and cones in the retina).
askscience	Right, that is a biological limitation (physical chemistry) of detecting high energy UV light, which would likely inherently require a higher turnover of protein synthesis to recover proteins / cellular damage. &#x200B; That being said, we also have engineered proteins used for EM imaging, which is extremely high energy, called miniSOG ([source](https://journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.1001041)). It's a little more complicated than I am describing here, but I am referencing it just to show that from a theoretical perspective you are right, but it is still possible to produce proteins that are responsive to high energy radiation despite those limitations.
askscience	That's maybe accurate how it was 100 years ago, but these days we have fossils detailed enough to see the ear bones, feathers, skin... We can read a lot into bite marks, footprints, and so many more things, compare them to modern animals. We can look at bones and determine how much it's carrying, figuring out how large of a muscle connected to it. We can look at the teeth and deduce their diet and thus their body plan. And all of this can be reviewed together and compared to really understand it. So this is a cool idea, but these days, it's just not true.
askscience	I feel like in general with the anti scientific sentiment over the last several decades people’s understanding of what we know and understand is unbelievably out dated. I mean we’re living through a golden age of astronomy but people dismiss then foundations of the science as little better than guesses even though they continued to prove themselves out. I love that we have proof of blackholes. How cool is that! Scientists predict this seemingly nonsensical thing, but that’s what the math shows. And now here we are , able to see their impact on astronomical bodies. One cool example is the black hole at the center of our galaxy who’s gravity is so immense that it’s causing the nearby stars to zip around it at unbelievable speeds.
askscience	As long as we have reproducibility crises like social psychology has right now, and as long as nutrition science keeps doing whatever nutrition science does, the general public will still be skeptical of science. Science as a vehicle of social learning still needs a lot of improvement; I read yesterday that there's an entire journal edited and funded by supported of Myers Brigg and by sales of the indicator. (Journal of psychological type). I'm not somehow shitting on science as a whole, I'm just playing a bit of devil's advocate here.
askscience	I don't think these people have the scientific literacy to figure that out. There's plenty of rigid science that is beyond doubt, and there will always be science that isn't all that pure. The issue is that people have been taught to distrust their government and corporations, I think. When he government is spying, listening to lobbyists, giving contracts to friends, testing diseases on its own people... What reason do people have to believe them that they should get a flu shot?
askscience	> Flipflopping between “this is good for you” to “this kills you” to “this is good for you” again makes anyone mistrust. But that’s typically the fault of science reporting, from the university press release to the mainstream media, feeling the need to sensationalize and define some absolute result. The actual scientific papers are usually cautious about their conclusions, and wouldn’t really conclude something like “X is good for you”. EDIT: [Relevant PhD Comics](http://phdcomics.com/comics/archive.php?comicid=1174)
askscience	I think peoples problem with the scientific community actually has more to do with how bizarrely and smugly entrenched scientific dogma can become, and how any scientists introducing radical new concepts are deemed "outsider scientists" are usually mocked out of hand. No matter how valid or invalid their point or theory may or may not be. Which I imagine strikes a lot of average people as pretty unobjective, odd, hypocritical, and confidence shaking. What considering how many times in human history outsider thinkers have introduced concepts that were initially almost instantly dismissed by mainstream science because it didn't fit into whatever model of reality was in vogue at the time. Only to eventually have the current model be proven wrong and the old way of thinking fall into archaic or pseudo-science. Sometimes after 100's of years of barking up the wrong tree because of it. I think scientists need to emphasize far, far more that there are things that are nonsense to them in science as well. But that it just means we don't know how something works yet, or that some of our general assumptions may be mistaken or not accurate enough. Otherwise to most people I think a lot of science just comes across as self assured, smug elitism based on a lot of opinion, and a handful of facts. Instead of the process that it is. Oh and maybe it's also time to finally admit just how personally and emotionally invested scientists can become in developing a theory.
askscience	I still see "wrong" (aka outdated) depictions of dinosaurs by scientists getting made. Less for sure. But I still see them. Them fat reserves often get forgotten about even by them. Since we only recently discovered just how much fat a lot of dinosaurs were carrying around. And don't even get me started on feathers and feather like structures, and how inconsistently professionals get what species had those right. From what I've seen dinosaur reconstruction is currently in the middle of an update. Not done with it.
askscience	Remember there is a difference between scientific reporting and scientists them selves. Most scientific papers are incredibly careful with their claims. Those theories that are outliers may prove themselves to be correct and in fact that’s exactly how science works. How science safely informs society is through consensus. The reason it’s so critical is because lay people aren’t actually qualified to determine which argument is right. Because no matter how many analogies are used, the underlying science and research are complex. That means these ideas (particularly those that make big claims) need to pass through the review process, attempts to reproduce the findings and looking to other fields that would corroborate the new ideas. Eventually when an idea is correct and stands up under rigorous inspection, that moves to the new consensus point. Honestly I used to see science the way you’re describing but the more time I spent studying science on my own, the more a realized that it’s often scientific reporters trying to bring in ad revenue than the scientists themselves who bring the big claims. The reason scientists who side with the consensus are so confident is they know how much evidence and study it took to make that understanding the consensus. Yes, scientists are people too and it can become personal. But the vast majority of scientists stick to their own field and just try to follow where the evidence leads.
askscience	I went to a private Christian high school in the late 80’s so I’m more than passingly familiar with it. I agree obviously about the alliance, but these are sincerely held beliefs by the majority of conservative Christians. I remember evolution being mocked well before the Reagan era. This was already part of the Christian world view, I think a push was made in the public schools as a part of it, giving us things like “teach the controversy “.
askscience	Even on those the arms and heads are cut super close to the bones and there’s no idea of frills or feathers or anything like elephant noses or rhino horns that may possibly have existed. Imagine T Rex with a prehensile nose that took the place of arms. (Chances are the skull would not support that but the fossil record wouldn’t keep a trunk we haven’t thought about intact either) So they were reconstructed saggy bags of meat and skeletons, but mostly browns, greys, and greens. Which makes sense if you look at modern lizards but not if you look at whales or kiwis. Don’t get me wrong, I love dinosaurs and now I want to ask what your favorite one is because in baggy meatspace I never get to talk about this, there are so many possibilities that are being proved/disproved everyday and without imagination and very specific science to investigate it we would be at serious loss. (So, what is your favorite dinosaur?)
askscience	Speaking as somebody who moved from true science with a degree in chemistry to social science with a degree in sociology. The issue isnxt that social science has false conclusions. The problem is that there are far too many variables to account for. In social science we look at a person with every second of their life being a variable. True psychologists or sociologists would never present something as absolute truth but merely as a widespread pattern that may apply to others. The real issue is people taking that idea out of context and saying that this pattern applies to all regardless of background.
askscience	>The issue is that people have been taught to distrust their government and corporations, I think. > Taught in the sense that they made the connection themselves, I'd say. Another example is in the media, where a person presenting an argument has their argument refuted by discrediting the person with whatever dirt they can find. This is a staple of politics. "My point is that global warming is happening under all our noses" "Yeah but one time you used baking soda instead of baking powder, so what do you know anyway?"
askscience	I don't think people have the stomach for (pardon the pun) thorough nutritional science. There are just too many variables at work and until we can account for all the variables in a system, it will be easy to dismiss as "bad science". My personal opinion is that this area could revolutionize the world in the areas if sustainability, health, and medicine. Designing the sensors that could analyze the chemicals and their reactions in real-time is a bit of science fiction at the moment. There us considerable work and money that would have to be applied. There isn't an apparent need right now so the status quo will continue.
askscience	The pressure difference is 1 only atmosphere, which is about 15 psi. Not much less of a difference than your average car tire to the air around it. Coupled with the hole being very small compared to the volume of air in the station, it's going to to take a long time to pull it all out. Edit: Reminded by another poster that I was being silly about gauges, a 30 psi tire is actually 30 psi difference with the atmosphere, making the pressure difference of the ISS to space about half the difference of a car tire relative to air, even less if you run a higher pressure than 30.
askscience	Air pressure needed to hold something up reduces as its containment surface increases. An average car with smaller tires needs a greater psi because it has limited surface area within the tire, but in contrast 10psi in a larger tire can hold up a greater weight. The big yellow backhoes with huge tires that are used in excavation can have as little as 20psi. So you are correct in that commonly psi for standard cars is in the 30-50psi range but in the same breath many, many tires operate on a much lower psi scale.
askscience	You don't come into contact with Space. It's literally just a vacuum. So no, the exact same space is in a vacuum chamber here on earth. What I think you meant is, is that the first time a person has been exposed in a vacuum, at that altitude? Depends, lots of pilots have been exposed to very-high altitude / near vacuum environments - it really depends, there's no line in the sand for what counts on this one.
askscience	I find it baffling that some people almost go out of their way to intentionally misunderstand these things. I have people in my life who do that a lot, and lately I've just started avoiding talking with them about many subjects, simply because they have to be technically correct about everything. It's like common parlance doesn't exist, and they need to show their superior knowledge. Even if the information is understood by all, parties. Not to mention it derails a conversation real fast.
askscience	[Well there was this one guy in 1960 that came pretty close.](http://stratocat.com.ar/artics/excelsior-e.htm) Pretty crazy story that was kept secret for a very long time. > Excelsior III, launched from Tularosa, New Mexico, carried Kittinger to 102,800 feet. During the ascent, the pressurization in his right glove failed and his hand began to swell. It reached nearly twice its normal size and was very painful. Afraid that he would be ordered to jump early because of the malfunction, Kittinger did not report the problem until he was at altitude. Seventy seconds before jumping, he cut away the radio antenna to prevent hitting it. For the first time in the flight, Captain Kittinger was truly alone.
askscience	E is the heaviest commonly found on pickups. C is much lighter duty. My understanding, which may be wrong, is that the letter rating is an old school thing and not as applicable to modern day tires. All it represents is the number [layers?] of belts. This might be expressed in the number of ”ply”, 8 ply or 10 ply. Today tires will also be rated in carrying capacity of load. You can find D rated tires with the same carrying capacity as an E rated tire, but it will be filled to a lower PSI, experience more sidewall flex, and it will weigh less. That's my understanding, there are also speed ratings. Those are another thing.
askscience	One factor may be that the hole, which was actually in the Soyuz orbital module, isn't thought to have been made in orbit but rather was drilled in the metal and improperly sealed (presumably with some kind of rubbery sealant) during the Soyuz spacecraft's construction. So as far as the mechanical behaviour of the Soyuz's hull goes, there's no sudden failure and no chance for a crack to propagate. A round drill hole will spread out any stresses, unlike the sharp edge of a crack that concentrates stress enabling the crack to grow.
askscience	No, what you're not getting is you don't "come into contact with space" - it's like, if I'm in a room with a light on, and someone opens the door I don't come into contact with darkness. And if I'm in a warm room, and someone opens the door to a cold one, I don't "come into contact with cold" - yes eventually I get cooler, but cooler than what - my original temperature? At what point did I "touch the cold"? This is why saying someone came into contact with space doesn't make sense.
askscience	The pressure in a tire is what's holding the vehicle up, as well as giving the tire the right "shape" for good traction and even wear. The heavier the vehicle, the higher pressure needed for both of those things. Heavy truck tires are filled to over 100 psi for that reason. Tires are rated up to a max safe pressure because they can be used on a range of vehicles. But the correct pressure is largely determined by the weight of the vehicle. So go by what the owner's manual says.
askscience	Odds are that would be a situation of choosing the wrong tire for the vehicle. Just because it fits doesn't mean it's right. But there are times a certain tire's ideal pressure will vary from the vehicle manufacturer's recommendations -- especially with specialty tires or extensive vehicle modifications. Most times the tire manufacturer will provide the correct pressure for a given vehicle. If you get into really crazy stuff it's an educated guess with some trial and error.
askscience	You're pretty much right on. I don't work for our seals division (which supplies seals for Boeing and NASA) but have worked with them in my BU, which is medical applications. There are tons of rubbers that O-rings are made from, from 14B to chlorobutyl to viton, to ePTFE which is a great temperature resistant sealing material. It's also ridiculously expensive so its only used when temperature swings are at play. Viton/ePTFE would be my materials of choice here due to their fluoropolymer nature which is very temperature stable.
askscience	>Arguably it would feel very hot after a while. Even assuming (This wasnt the case) a 2mm hole was facing directly at the sun, its 2mm. Very, very little energy, even in space would be hitting you in the first place, and it would take hours to heat your finger any appreciable amount. That and you would have not only the rest of your body to act as a heat sink, you have the entire ISS. My understanding is that your #1 concern, besides the whole "Leaking air in space" thing, is a tiny chunk of dead skin from the slight pressure limiting blood flow. It would take some serious willpower to prevent moving your finger a fraction of a millimeter for a couple hours.
askscience	The sum of the kinetic energies of the products, minus the sum of the kinetic energies of the reactants is called the "Q-value". This is the net amount of energy released by each individual reaction. For thermal neutron-induced fission of uranium-235, the Q-value is about 200 MeV, on average (average because there are many possible final states). For fusion of deuterium with tritium, producing a neutron and an alpha particle, the Q-value is about 17 MeV.
askscience	I see... I'm getting a bit confused because in this book that I have it defines the mass difference (aka mass excess aka mass decrement) as Delta = M - A where M is apparently given by the semi-empirical mass formula and A is the mass number. Then the book gives the energy of a neutron, using this Delta, as 8.0714 MeV. I'm not sure how they arrived at this value. From my understanding, mass defect has an associated binding energy which tells you how much energy is needed to free the nucleus into individual nucleons. But a neutron is already free so how can it have a mass difference whose corresponding energy is 8.0714 MeV?
askscience	Ahh okay so the mass excess aka mass defect is not the same thing as binding energy? So it is possible that there is mass excess but not binding energy? E.g. a neutron has mass excess, since its mass isn't exactly 1 amu (which is defined in terms of carbon-12) however it doesn't have binding energy, since it is a lone nucleon. So the binding energy and the mass defect expressed in terms of energy (via mass-energy equivalence) are different?

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