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cgp89m | How do you immigrate to the United States of America? | Since it may be a while before you get a *serious* answer that goes into real detail, I'll give you what I know: You have to file for citizenship, take a test, pass a background check, and pay substantial fees every step of the way. This is a short explanation, but in reality the process takes many months and often years. The agency(ies) that process applications and application-related information are slow and understaffed, and the process itself is anything but streamlined. When and if you are approved, then congrats! You're a citizen! | a39244aa-33b6-43de-be8b-36c9b77fcaf2 |
cgpm1n | When a large ship is launched into a body of water does it raise the water level? What about when that ship enters a new body of water ? Is it possible to calculate? Is it the same principle as sitting in a tub of water? | it will raise the water level. the volume of the ship that is beneath the water is "added" to the water by displacing it. in total it raises the water level by the same amount as if you would add water of that volume.
which happens to be the amount of water which weight is equal to the weight of the whole ship. | 010f0d4e-0e2d-4ffc-b6d7-123caeec4936 |
cgpoia | If drums produce sounds that correspond to certain frequencies (e.g., C#, F), how is it that drums, when played, do not clash with the songs in different keys? | They do, it's called frequency masking. Mix engineers put a lot of effort into dealing with it, both live and in recordings. Cymbals are a particular nuisance.
They don't necessarily clash harmonically however. That's because tuning the drums with a drum key is necessary, but only for the more tonal pieces of the kit (snare, tom, kick). Pieces of the kit that can't be tuned usually come in different keys/pitches, like triangles, claves, cowbells, etc. Not everyone uses the correct pitch for a piece, or tunes for every tune, but our ears are accustomed to listening to it (unless you're really anal retentive about it).
A compounding factor here is that drums, even pitched ones, have much more complex modes of resonance than other instruments. Even if it's tuned, you can get enharmonic frequencies, and our brains don't really deal with that well so we just hear it as cool noise, especially when it decays fast, as in a drum. We have less time to latch on to the fact it isn't in key.
There's also the fact that when you get into physical acoustics (sound through solids) it gets weird. The speed of sound isn't constant in a solid for example, so internal reflections actually change the resonant modes as the system resonates. That and solids don't vibrate in nice ways like air in a woodwind, a string fixed at two points, or a membrane (same thing as a string, but the tension applied is in two dimensions). If you see a video of a bridge collapse due to resonance you can actually see the bridge twists, rather than moving just up/down and side to side. Same thing happens in say, a woodblock or some claves. | 8eaafc57-59dd-4aa4-8b64-163d195c89f7 |
cgpsyz | Why do people automatically stick out their arms when frustrated or confused (AKA universal WTF hand gesture) and why is it universally done and understood? | are you referring to shrugging, showing the palms of the hands? I don’t know if it really is universal but if it is, it feels as though the gesture were a way of showing: hey, look, i am NOT in control here. it is literally out of my hands. and that equates to: don’t blame me for this shit | b0bed92c-7a75-4268-bf2b-238abe4e5f20 |
cgpszq | How do so many space artifacts end up orbiting Earth and endangering us, instead of falling into Earth or off somewhere else? | They don't have enough energy to go off somewhere else. The escape velocity for the Earth is about 11 km/second. Anything going less than that will stay in some sort of orbit, maybe circular, maybe very eliptical. The only way that won't continue is if the orbit intersects
with the Earth or the orbit dips low enough to be slowed down by air resistance to make the orbit intersect, and then they crash land or burn up. | b61b464b-01a7-4f45-af0f-e395b0f0f6e6 |
cgq680 | Aerospace has never been this big since Apollo, and rocket launches have never been this frequent,, How do nations not mistake another nation's rocket launches for a hostile action? And also, do nations conceal their "true intent" behind commercial launches? | To answer your last question first, yes, sort of. Governement space launches often have classified payloads. It may be a satellite with an unknown or classified mission, or even a classified payload or system on board an otherwise known about satellite. Your open source example here is GPS, which is owned an operated buy the government but it is well known that there are at least two different location resolutions and many different sensors on board the crafts.
As to your first question, they have to tell someone, so everyone knows. When a scheduled launch is planned, flight paths have to be closes and the FAA notified. Other countries must do the same. So when a civilian or government launch is planned, pretty much everyone knows. So when a launch outside that area or window occurs, it gets some special attention. This is not addressing rouge states such as North Korea and the like, who don't typically make pre-launch press releases unless it is to be used for propaganda. Often times, satellite imagery can simply confirm build up of machinery and launch equipment at known launch sites however, so even without warning, they pretty much know what's going to happen. | fe1137b1-a0b3-40da-80a9-f06b2519eb47 |
cgq7di | Why does thunder in the distance sound like a low-pitched but long duration kinda "rumble" akin to the sound of a jet overhead as opposed to the "CRACKBOOM" experienced when it's close? | The lightning super heats the air ss it strikes. This causes a turbulent air column to collapse on itself, creating a sonic boom.
But each branch and fork of the lightning is like its own mini sonic boom.
When you are close, those are all so close together in happening, that you hear them all at once.
Far away, though, the difference in their initial starting positions, and how the sound travels through the air, makes them at hit your ears at different times.
Imaging throwing five rocks into a pond at the same time, in roughly the same location.
The initial waves would all look like one wave ring, but after that, you would see a large variation on the wave pattern, the further you were away from the splash. | abe5952f-02a0-4bfa-b5a8-8da0d9caab36 |
cgq85k | Why do insects like flies rub their eyes/heads with their legs ? What purpose does it serve ? | They cannot blink so they clean their eyes with legs. Their legs also have brushy hair called setae which are very sensitive and inform the insect if anything is on them (mold, dust, whatever). They also have little hair on their entire body that acts as an advanced sensory organ. This also has to be clean. | d9ab782f-60a1-422f-941a-1b465facb26e |
cgq8xy | How does blinking moisturise/hydrate eyes? | Your tear ducts secrete tears, which lubricate the eyes and keep them moist. Blinking spreads the tears around so they create a protective/lubricating/moisturizing film on the whole surface of your eye. | 4057ec1e-6a52-40f5-ae44-661c22d6296a |
cgqbd9 | With the history of large ships being taken over by "Somali pirates" or whatnot, why aren't those vessels outfitted with mounted machine guns, and a couple GTFO rocket launchers? | They aren't legal - even the USA doesn't allow non-military ships to have such weapons. The age pf piracy made sure all nations signed up to this. The high seas would be chaos if any ship could be armed to the teeth. | 6ec3a46c-202c-4aea-b1b3-6cc30a7b3086 |
cgqc5r | If I buy a 5 kwh solar system and the efficency of the panel is 20% do I only get 1khw? | A 5kW panel will generate up to 5kW of electricity. Due to the sun rising and setting and the weather, you’ll only average about a seventh of that, even if the panels are ideally positioned. So 5kW times 24 hours divided by 7 gives around 17kWh per day, on average. In the summer it could be more than double and in winter less than half; much depends on the climate where you live, orientation of the panels, and any shading from things like trees and houses. | 7fea2e8b-5937-4f9a-b10f-32a1f3f97164 |
cgqe5z | Why don’t we, as passengers, feel the speed of a plane whilst it is flying? | The plane is cruising at a constant speed. You feel the accelaration at take off but once the speed of the plane (and your speed too) is constant you wont feel it just like in a car too. | dd093682-d990-41eb-863c-4c4c1f4b6c8c |
cgqku1 | why do some antidepressants have "suicidal thoughts" as a side effect? Is'nt it counterproductive to take these drugs and still have those tendencies? | Nobody AFAIK has invented drugs to block specific types of thoughts.
The problem as I understand it is that sometimes, in some people, the first lift in mood (from say, an SSRI starting to take effect) gives the person the energy/motivation to actually carry out a suicidal plan, whereas beforehand they couldn't make themselves do it.
But "suicidal thoughts" is shorter to put in the black box, and gets the idea across. | f917b1c6-c702-4e5a-85f9-73a4457794a0 |
cgr02y | Heron's Formula | Heron's Formula is that the area of a triangle is sqrt(s\*(s-a)\*(s-b)\*(s-c)), where a, b, and c are the sides of a triangle and s = (a+b+c)/2. I don't think there's really an intuitive way to understand *why* it works, but you can prove that it does work.
[One way](_URL_0_) to do it is to split the triangle you're looking at into two right triangles by starting at one vertex and drawing a line to the opposite edge. Right triangles are easier to work with because you can use the Pythagorean Theorem to relate the sides to each other. Do some algebra and you can get to Heron's Formula. | ccb4e8e0-3451-4202-976b-ac4c0a861160 |
cgr1tu | why does matter bend space? | Since Newton we know that mass correlates with gravity. Which is only half of the truth.
For example, take an apple. Measure it's weight.
Now, shrink the apple. It's weight is the same as before. But since the apple is now only half as big as before, the ant crawling the apples surface feels a much stronger gravity pull. Shrink the apple even more, you get a black hole.
Einstein realized that to make sense of this and to be in accordance with the data from experiments, mass, gravity and space/ time had to be related to each other. And once he got the mathematics straight (he himself said he had deficits in math), he realized that indeed, gravity is nothing but curvature of space and time.
As to WHY mass bends space and time... As I said before, no one knows. | e6374e35-cd35-4b42-9803-fa6c94de2427 |
cgr4jt | why can we control some things our body does subconsciously like blinking and breathing. But why can we not control other things like making our hearts beat faster? | We cannot directly control our heart beat because the heart only has autonomic nerves. These are involuntary. Breathing, blinking, swallowing all have muscles that have somatic nerves, meaning we can voluntarily move them. They are also autonomic responses, however we can control certain muscles that allow us to resist this. | bff62797-3f3c-4296-a6dc-e25d9dabbeef |
cgr8oy | why does a hot day or hot room make you so tired and weak? | Scientists say that energy from the sun transfers heat to the body through electromagnetic radiation in the form of photons. This radiation causes body temperature to increase. When your body temperature changes more than .5 degrees, your body reacts by being sleepy, grump, or tired. | 15be9828-c9c2-4b24-98b5-44d53fb767eb |
cgr9za | How do ‘bad’ carbs cause increased inflammation in your body? | Glucose in the blood causes inflammation
What's so bad about sugar and refined carbs is that it is absorbed very fast and spikes your blood sugar because there are no fibers and other nutrients due to the refinement process. | 466777c2-5bb8-4c19-8ec1-d86c47885971 |
cgrjwf | What is the academic reasoning behind believing we live in a simulation? | IMHO, (layman here) is that there is not a "belief" that we live in a simulation. It is a philosophical position that we cannot rule out by our reasoning that we are not living in a simulation. There is nothing we know of (by observation or reasoning) that contradicts this position. This does not imply belief or support - simply it is something that cannot be ruled out. | 3691d834-f7cb-4e64-aba0-66d60106de56 |
cgrrc3 | How does Olaplex No.3 Work? | As it is proprietary, I'm guessing the best you can do in understanding the motivation is reading the relevant patent [here](_URL_0_). It gives specific chemical interactions among other things. | a0b9b971-79f0-4062-bdf9-cc375b070d39 |
cgrtes | Why does China use two currencies CNH and CNY? | China does not have two separate currencies. Rather, the Chinese government treats Renminbi (yuan) differently dependingbon whether it is currency that is within China, or outside of china.
Lets say use an easier example, lets say you are a US citizen and have some Canadian dollars (CAD). If you go to a seller here in the US with your CAD, they may not be very appealing, and the shop owner might want to charge a higher price. If you instead go to Ontario, and offer to buy the same product, you will may get a better deal.
This is basically what happens with every currency all the time. There may be different exchange rates between different parties (banks, sellers, buyers), but in practice it should more or less equal out to the market rates because one player is directly manipulating exchange rates.
In China, the case is a bit more complicated. China considers currency within china (CNY) differently than currency outside of china (CNH).
If you hold any Chinese currency outside of china, you will likely be converting it at rates driven by market forces, the same as any other major currency.
however, if you hold Chinese currency inside China, the central bank of China will directly dictate what the exchange rate is. This results in a difference between the two exchange rates, and causes t the two different ticker symbols, even though all the currency is the same.
_URL_0_ | f9095653-baf2-4512-8b27-51e9d4758292 |
cgs5gp | How does fiber-optic internet work? | We are next door neighbours and I have a red laser pointer. Whenever I bake cookies I want to invite you over to eat them. So I shine the red laser pointer at your house.
You have a blue laser pointer. If you are busy and can’t come over to eat the bookies, you can shine the blue laser pointer and I will know to save cookies for you.
Fibre-optic Internet is like that, we shine lights at each other through glass cables. We can tell each other many things by shining lights into the cables. We can tell each other what’s the weather like, recipes for good cookies, watch YouTube videos and so on. | 28ba25b0-9359-486a-bb72-ea0a294fa62c |
cgsb1f | Why is it so hard to find a reading position that doesn’t become uncomfortable after five minutes? | Because you're straining a particular set of (small) muscles continuously. Holding a small object still for a long time is not something humans evolved to do particularly. | 51978093-eb21-49ce-bac8-4b603959fe00 |
cgsdy0 | Why do politicians resign from their government as a protest? Do they not have more power staying in their post to fight against what they don't like? [UK example inside] | Like you say, jumping before he is pushed.
The PM decides who's in the cabinet and what roles they have. If he fundamentally disagrees with the PMs approach, then he would be fired anyway.
Chances are the new PM will change up who's in the cabinet anyway.
He remains an MP and a member of the Conservatives. He has simply resigned as a minister. So he still gets to vote in Parliament, and can vote against Johnson.
He could be expelled from the party if he keeps voting against the government, but even then he would still be an MP and still get to vote. | e01237a0-5395-439e-8dcf-c2d012b84138 |
cgsiee | How can domesticated animals change when in the wild? | Generally speaking, when domesticated animals escape into the wild their chances of survival are not high due to their domesticated nature.
With regards to some farm animals escaping, the rapid change in their physical appearance would be down to one of two reasons. Firstly, some farmers will trim horns or tusks to prevent injury to other livestock and potentially themselves. The livestock is their livelihood and if they are injuring each other its going to cost them. When these farm animals escape into the wild there is no farmer to trim their horns/tusks so they simply grow back.
Second reason would be the need for survival. Most livestock are typically speaking prey animals and when kept in safe pens with food on tap they will have had little to fear. When in the wild and faced with potential predators they need to adapt to survive. However, as I mentioned above, as they are not used to having to fend for themselves and find food, most domesticated animals would not last long in the wild if they could not adapt quick enough. | c4953e44-3c3e-4fde-a8b1-32e5ca278daa |
cgsjda | Why light and the rest of electromagnetic waves don't interfere with each other? | All your questions can be answered by understanding the concept of wavelength.
Basically speaking, once you know what the wavelength of every radiation is, you can predict how it will interact with other things.
I'll give you an example you probably didn't think about:
Why do car radios start to have bad reception in muntain tunnels? Well, the wavelength of radiosignals is pretty big, but the width of the mountain walls is bigger, therefore you start getting white noises and such. | e39957d2-5bed-4859-bb75-699919a2c6ad |
cgskm2 | What happens in your body when you’ve been constipated for days? | It's [not good](_URL_1_).
Poop is where everything your body doesn't want goes. If your intestines are packed too full of shit, they'll begin to rupture and leak poop into your blood stream which is life-threateningly-bad.
If you haven't shit in a couple of days, drink some coffee until you do. If you're lactose intolerant, maybe it's a good time to see what milkshakes are all about.
If you haven't shit in a week, it's time to get some laxatives (not stool softeners) from the store. Milk of Magnesia or [Colon Blow](_URL_0_) or something.
If THAT doesn't work, it's time for a trip to the Doctor. They've got the good stuff that may require a IV for dehydration because it cleans you out so well.
If THAT doesn't work, you've probably got a blockage and someone's got to roto-rooter your ass out to get things going. The good news there is that you're usually riding that Kracken out high on pain meds, so you've got that going for you. | 93ab3b4a-25d9-42d6-8161-6cf9669a41e5 |
cgsq67 | Why doesn’t water go up your butt if you jump in a pool? | Something tells me you just might not be a real doctor!
It’s all to do with your anal sphincter | 97e0e958-d559-4ffb-8afd-42653878ca63 |
cgsvn5 | How a bunch of moving electrons can power homes? | A moving electrical current produces a magnetic field--so while the electrons aren't directly striking the rotors inside a fan, they *are* creating a magnetic field that is pushing against the rotors.
That's the basis of any motor: a moving electrical current causes a magnetic field. If you put some pieces together in the right ways and shapes, you can make it so that this magnetic field causes a central shaft to spin. In the case of a fan, that shaft is just hooked up to the blades, making the fan spin.
Light from a bulb is a little different. In incandescent bulbs, the electricity flowing through the filament makes the filament so hot that it produces light. In fluorescent bulbs, the electrical current electrically charges a gas inside the bulb; the gas produces light when it jumps down from one energy level to another. And in a LED bulb, LEDs produce light in a similar way to the fluorescent bulbs, except they're solid instead of gas. | 25c3afad-50a6-481d-b782-fd54f9b86568 |
cgt2vy | Why are civilians targeted by militias in the Democratic Republic of the Congo? | Ultimately that is a question that depends on the nature of the specific militia, its terminal and instrumental goals^1 , the attacks and who the people targeted were beyond just 'civilians'. Without that knowledge all I can really do is speak generally.
Generally a terrorist group (with political goals, most do but some dont) if they attack civilian populations do so as they view that population as either complicit in or representative of what they have issue with. They probably don't think their actions will have a direct effect at achieving their endgoal, but rather it can be a show of power against state government to rally support, reduce the legitimacy of government and its ability to protect them in the eyes of the population and to sow general fear which might serve the groups political goals in some way.
Louise Richardson's *What Terrorists Want* is a good book to read on this topic.
A militia though is different in nature to a terrorist organisation, its goals, structure and methods are more akin to a conventional army than a terrorist group. They might attack a civilian population in a counter-terrorism effort as terrorist groups usually derive most of their material support from civilian communities, though efforts like this usually backfire. They could be using the civilians as an exploited labour force, which in Central Africa is not uncommon due to conflict resources. They could be acting in a terrorist capacity themselves and doing it for all the same instrumental goals.
Really it just depends. Conflicts like this are messy, there is no easy universal answer especially since your question is quite broad.
1. A Terminal goal is your final goal, an Instrumental goal is a goal you want to achieve in service of achieving the terminal goal. If being a doctor is your terminal goal, going to medical school is a likely instrumental goal of yours. | be1971f1-c1d3-41b3-88cd-b8d13ea1c210 |
cgt8x5 | Sex workers in modern times have acces to many forms of birth control. It is also a well know fact that sex work is one of the oldest professions in the world. How did people prevent pregnancy before the invention of modern birth control methods? Was birth control even used? | There are plants that can induce abortion/miscarriage; a woman could consume those. There were also medicines/mixtures/potions (whatever you want to call them) that would have the same affect.
They couldn’t really ‘prevent’ it beyond not having sex when they were fertile; but they could end a pregnancy | 62d6159d-1f6d-45d2-b790-fb705a0e6df9 |
cgtctz | Why is staring at a solar eclipse deemed to be dangerous and what is the difference from just staring at the sun? | When you look at the sun your eye goes "Damn that's bright, I better do something". This causes your pupil to shrink down REALLY small to not let much light in, and also causes a reaction to flinch away. Both of these protect your eye from damage.
If you look at a not-quite-total eclipse your eye goes "This is pretty dark" and makes your pupil big to let lots of light in and doesn't trigger those protective reflexes. But any part of the sun "peeks" around the eclipse is just as bright as it was before, which means it can cause damage to the light sensitive bits in the back of your eye. | e4f6f9dc-1661-4296-8355-2a4a828371fc |
cgthds | Why is some ice completely clear while other ice is opaque? | A lot of it is dependant on how the water was frozen, where water that is slowly frozen will be more clear, as less air and impurities will be caught in the ice. This is why icicles are usually really clear | 620ec5b1-5e8f-4fac-9595-577de240e712 |
cgtpnq | How does the open refrigerator at the store with cheese, butter, etc. not spoil the food, but our refrigerators at home need to be closed? | Fluid dynamics!
The refrigerators at a store rely on something called "laminar flow." There are fans at the top of the fridge that blow air along a straight path where all particles are moving in straight lines ("laminar flow", as opposed to "turbulent flow" where all the particles are moving in different directions).
This creates an effective curtain of air that pushes warmer air out of the way, creating an invisible door made out of air.
It's not as good as a real door, of course, but it's more than good enough for a dairy case. | c5c2c7be-8932-43d1-92f2-ea7c5549d80f |
cgtxa9 | why is it more devastating to detonate a nuclear bomb at a distance above ground, as opposed to directly at ground level (upon impact) ? | If you detonate a bomb at ground level then a lot of the energy is spent digging a hole which is useless. You want the bomb to have a clear line of site to a large area for effective destruction
It's also important to note that if a 10 PSI overpressure will collapse most reinforced concrete structures then there isn't much value in hitting them with a 50 PSI overpressure, they're collapsing either way. Nuclear bombs are generally detonated at a height that maximizes the range of their 5 PSI overpressure which will knock down most structures and is almost universally lethal
There's also an interesting effect where the shockwave hits the ground and then bounces back up still expanding. This means that the edges of the shockwave are extra strong because they're the combination of the initial shockwave coming outward from the bomb and the shockwave reflecting off the ground. This results in extra damage and increases the radius of the 5 PSI overpressure. | bc9740a4-7e54-4162-ba6a-1b80f7fa79e9 |
cgtytg | Why can we see light reflections from an angled surface? How are photons getting back to us? | You're following the old axiom from physics class of "the angle of incidence = the angle of reflection". Physics class almost always modeled the world with a level of perfection of surfaces and materials rarely or never really found - e.g. the frictionless surface, and in this case "the perfect mirror".
To that point, in your example were it reflecting _perfectly_ as a sign it would _be a mirror_ and you'd not be able to see it was there other than that the world would look strange in the spot occupied by said "sign-mirror" (e.g. you'd see a tree trunk start at 10 feet of the ground and end at 12 for that 2 foot tall sign and an lots of sign poles with seemingly non-existance signs!).
So...we don't build signs as mirrors, we build them as ... signs, and their surfaces are so imperfect that that they bounce light back in nearly all directions. In fact, the surfaces of these signs are designed to have the reflecting surfaces be nearly omnidirectional. Imagine pasting sand on top of a sign and each grain of sand is pretty reflective. Each grain of sand would be oddly shaped and at least a lot of surfaces/edges of sand would be bouncing light back in the direction from which it came, not using the orientation of the face of the sign.
TL;DR: Light does work that way, but surfaces of materials on signs aren't flat and parallel to the face/orientation of the sign. | 6eae5bf5-87a8-4b77-9daa-f60e9fb178d5 |
cgu8jx | Why are animal sounds different in different languages? How did their spellings originate? | Different languages use different sets of sounds, and different ways of stringing sounds together, to make words. For example, the way an American would say the 'r' in "red" doesn't exist that way in Japanese. Another example, the way a Francophone would say the 'r' in "rouge" doesn't exist in English.
The sounds that things make, such as animals, are described differently based on the sounds of the language being used. We think cats say "meow" because that makes sense by the standards of English. Japanese people think cats say "nyan" because that makes more sense when you're working from Japanese sounds. Nyan doesn't make as much sense in English, and meow doesn't make as much sense in Japanese. | 7686dc69-7872-46b3-8e5e-1a769201fd1d |
cgudfi | Why does Jupiter look black / invisible from this picture? | That picture is taken from the shadow of Jupiter. You're seeing the "night" side of Jupiter, except for a tiny curve of "twilight" Jupiter. | 0df39450-17d6-49c1-8061-d68a3b908b76 |
cgv8qt | How was Amazon able to pay $0 of Federal income tax on over $11 billion of profit | Your parents give you $20 to start a lemonade stand, under the condition that for every dollar you make, you have to give them $0.10.
After a full day of successful lemonade selling, you made $10 profit. This usually implies that you owe your parents $1, but instead, you use those $10 to buy a bigger pitcher, make your stand a bit prettier, and buy more lemons for the next day. You used up all of your profit, leaving you with $0 total profit for the day, and $0 owed to your parents. | d07f043f-4b6e-4ecf-aa77-ed1adead6ee5 |
cgve6h | Two headed creatures | Polycephaly is caused by the same thing as conjoined twins. Basically, during very early development, one of the cells of the initial foetus goes "Freedom!" and starts to form as its own baby. Then it changes its mind and goes "Actually, do you mind if I just creep back in here?". This makes the cells very very confused, so you tend to end up with two brains sharing the same organs to a certain degree (often, they'll have their own set of some organs, such as the spine, heart or arms).
Control is often a complicated matter. Each brain tends to control its own related organs, but one head may be anencephalic (a condition in which the neural tube doesn't close properly so the majority of the brain never forms, leaving the animal extremely primitive and incapable of most emotions or higher thought), and often an organ may be controlled by both nervous systems simultaneously. Enervation in this kind of animal is something I don't know very much about, and I don't think *anyone* knows much about it.
It happens more frequently in reptiles because reptiles are highly susceptible to environment. Development is an incredibly complicated process that's very sensitive to stimuli such as temperature. Reptiles don't incubate their eggs, they just put them down and get on their way, so temperature fluctuations, among other things, mean reptile eggs are much more likely to undergo deformity-causing processes. It happens sometimes in fish too, although temperatures in the ocean are much more stable so fluctuation doesn't have anywhere near as much of an effect. | 43bdfff3-52ab-421f-9020-59e9b3e799f5 |
cgvgz0 | How does food end up in your stomach even if you eat or drink upside down? | Muscles in your esophagus squeeze it “down” the tube to your stomach. Kinda like trying to squeeze that last bit of toothpaste out of the tube. | 02ee5f9f-aa53-43ed-99c5-71e595ee644c |
cgvn8l | How is the British Prime Minister selected by such a small group of individuals? | The conservative party are in power, and the conservative party members elect the leader of the party. It's that simple. | 66f087f3-4eab-418a-94c5-259273b86db6 |
cgvou7 | Why is particle movement considered random? | You're mixing up two different things.
You can "move your hand", because muscles connected to your rigid bones are articulated in a useful way. Your brain (where your "will" lives) can control those muscles to a certain extent.
Each atom that makes up your hand moves randomly. This is usually called "heat" and is motion in a very small region of space. If an atom moves this small distance, it hits another atom and bounces off, so the net effect of this motion is too small to see. This is not a function of your "will", the atoms in a steel bar on your desk are doing this and steel bars have no free will (I claim). | ecc9b257-b68f-4f4c-b1e2-caf7f9a3a5b4 |
cgvpt8 | since when and why do seagulls eat small animal, I recently saw a video of a seagul eating a small rabbit whole like a snake really freaked me out is that actually a seagulls normal diet? why do they eat small animals? | They’ll eat anything, they are greedy greedy bastards. There’s a town called Whitby in the UK where they’ll just attack anyone who has food. | f037088b-2e2d-4dd5-a85f-82b5107032bb |
cgvxun | Why do humans have dominant hands? Why aren't we all ambidextrous? | The neurons that control your left hand are not the same as the ones that control your right hand. If you taught one to write and not the other, then you made yourself one-handed as a writer. It's a parlor trick to teach yourself to write with both hands, but it takes hours that most people aren't willing to commit. Plus, when you write with both hands at the same time on the board in class, it leads to anti-intellectual jokes which are not pleasant.
Fun Bonus Fact: James Garfield, 20th president of the US, could write Greek with his left hand and Latin with his right hand simultaneously. Oh, the things you could learn in the 1850s due to the extra time on your hands. (pun intended) | 13431dbd-e6b9-4d83-86d4-c8515c01bccd |
cgwgm4 | why can animals drink out of a lake or body of water and be okay and we can't? | well, you can, you just have to get used to it. BTW, if you've drunk clean water your whole life, drinking water in India or Mexico will usually make you very sick at first, but once you have developed the right gut bacteria from drinking that water, you'll be fine. Truth be told, some people never get to "fine"... | 189e6055-1a43-41c8-b759-d6dabd1223da |
cgwj4b | Is there any purpose of nipples on men? How are they created? | In the womb, we don’t start as male and female separately. We have a single starting template, that’s mostly female like, and then differentiate as we grow. Ovaries migrate downwards to become testicles, for example, and the genital ridge (the precursor to vaginas and penises) expands and grows into a penis.
Nipples are simply part of the starting template, and males do not develop in a way that makes them go away. They’re not strictly intended to do anything, but there’s not really a reason to get rid of them either.
Since the breast and nipple is a complex design, with alveoli (little tubes) lined with milk production cells, males just never activate these structures. They’re still there, but inactive. It would be a lot more work to try to absorb and alter them for no particular gain.
Fun fact: males can lactate, or produce milk, under the right circumstances. Some men have taken the hormone prolactin, which activates these structures, and breastfed their children. | b85c4e1b-2e76-4ce2-8da6-43b9ecd44c47 |
cgwk14 | Why aren't there planes with solar panels on their top? | Planes use fuel engines, not electric ones, so it wouldn't help generate more fuel. It might help powering the electronics without using the alternator or similar, but planes burn a lot more energy than would possibly be generated by solar panels of its size. For reference, a modern car might go 40 miles with 1 gallon of fuel. A commuter plane uses something like 1 gallon per second, at 500 mph this gives something like 0.15 miles per gallon of fuel. | 03920a57-7d4e-441a-ba08-e6e0c2be1f0e |
cgxa80 | why are insulated metal containers always hand wash only? What harm would the dishwasher do to metal? | Some are simply because the dishwasher can damage the finish on the metal if it's colored/powder coated, etc. But the heat, etc. of a dishwasher can also break the vacuum seal on insulated contrainers, rendering them a lot less effective at keeping things hot/cold. | 3e7e2482-1ced-4427-8524-6d2604d85911 |
cgxd1l | Why sometimes we only remember how to do something when we start doing it? | Brains are associative: for singing you strongly learn the word before leads to the word after, and with a given pitch. You can also learn muscle movements instead of what exactly you are moving to: for example close your eyes and tell me the left-to-right, top-to-bottom order of your keyboard without using your fingers. | 86e068e1-377a-4056-af38-c2b1eeba70c0 |
cgxdu7 | How does seeing a crush or a SO cause the feeling of lightheadedness and 'butterflies' in the stomach? What are the butterflies? | I always associate it with anxiety. Similar to performance anxiety. Butterflies aren't a positive experience for me, but the attraction and excitement associated with a crush also combines with this anxiety making it a wonky feeling. | 003dd979-6eb6-4f1c-a535-890556d2473e |
cgy25n | Why do speakers get blown out when you play them too loud? | The voice coil in a speaker is an electromagnet, it vibrates back and forth against a permenant magnet. The voice coil can overheat due to too much power being sent to it. Or damage from moving too far forward/back. | a452727e-4edd-49b6-9fa9-69a16d889731 |
cgy390 | Why was JFK assassinated? | Because Oswald was a mentally disturbed idiot. A psychiatrist in his childhood suspected he had a disturbed, schizoid personality. He was a pathetic loser who tried to compensate for it by seeking out counter-culture, such as Marxism. In this way, he was really not that different from someone who claims the Earth is flat. They're just pathetic little morons who want to feel special. Anyway, Oswald made trips to Russia and was a communist wannabe.
To quote the Warren Commission:
> It is apparent, however, that Oswald was moved by an overriding hostility to his environment. He does not appear to have been able to establish meaningful relationships with other people. He was perpetually discontented with the world around him. Long before the assassination he expressed his hatred for American society and acted in protest against it. Oswald's search for what he conceived to be the perfect society was doomed from the start. He sought for himself a place in history — a role as the "great man" who would be recognized as having been in advance of his times. His commitment to Marxism and communism appears to have been another important factor in his motivation. He also had demonstrated a capacity to act decisively and without regard to the consequences when such action would further his aims of the moment. Out of these and the many other factors which may have molded the character of Lee Harvey Oswald there emerged a man capable of assassinating President Kennedy.
& #x200B;
TLDR: Oswald was a pathetic loser who wanted to get attention by killing someone important. I'm sure that if he lived in the 2000's, he would have been an active shooting spree or one of those ISIS wannabes. | 7c908b0c-a02a-45d1-afe1-c6c00ba5cc20 |
cgy4k8 | Why are smaller blueberries significantly sweeter than larger blueberries | There are lots of varieties of blueberries.
* Some are sweeter than others
* Each has a different maximum size
* Mature at different times on the summer calendar
The most common store varieties are large, have good shelf life, box well without damage, but don't have much flavor. Instead of letting them sweeten, they pick early to minimize time to market and minimize crop loss. Fortunately customers don't know what they are supposed to taste like.
Your sweeter berries were of a naturally sweeter type and were picked later to let the bush pack them full of sweetness. All varieties will be super sweet if left on the bush long enough. By the time the store variety gets sweet the birds have eaten them all.
Source: Have about 5 blueberry varieties in the garden. | 7f7d55ae-a294-4f49-a338-45198c21b0d2 |
cgy60l | how are some flying animals (e.g - sparrows and house flies) able to fly at such a high speed without bumping into anything? | The brains of flying animals are specifically evolved to handle the calculations and processes needed for flight. Humans bump into things when they move at ridiculous speeds because we evolved to move at medium and low speeds, dedicating more of our brainspace to things like language. When your entire brain is fly, eat, don't die and have babies, it turns out you can actually dedicate quite a lot to not bumping into things. Also, flying insects *do* bump into things all the time, they're just small enough and tough enough they don't really care. Meanwhile, the brains of birds are just tiny miracles which do way more than they should be able to. | 441c9aab-3261-4059-bb2c-7a80af7b7f36 |
cgy820 | why are wind turbines giant 3-wing fans as opposed to other designs such as a rolling cylinder or even multiple smaller fans/cylinders? | Bigger systems take more material, and have more weight requiring stronger supports which increase cost.
That, and you waste energy spinning up a heavy turbine, so the three turbine design minimizes those concerns while trying not to sacrifice the ability to harness the wind.
But those other designs do exist and are used. | 9bbc904a-6373-48a6-b25b-630cdaa3f455 |
cgydn6 | How did UDT navigate dark waters when visibility is nothing? | Most of the time they did dead reckoning. That is to say that they went in a straight line until they either hit something or until they figure they have gone far enough. This did actually work sometimes but at least it brought you closer to your target. They would also pop their heads/periscope above the water for a few moments to try to find recognizable landmarks that they could use to navigate. Even if it is completely dark you might have some light when your eyes have adjusted. You might use the light from the moon or the stars to both orient yourself and to spot landmarks. Houses and cars might have some light on them which is easy to spot in the dark or use as light to see other landmarks. Guards also tend to smoke on duty which gives off tiny spots of lights that can be seen for some distance. Then it is back into the dark depths of the water and continue on dead reckoning towards the intended target. | 0f0b2536-fe04-488d-a1df-4a8b6475eb67 |
cgyimr | Why do generators and electricity in general make a buzzing sound? | Alternating current is used for most electrical transmission, and it's also in the walls in your house. The North American standard is 60 Hz, which means that the current alternates 60 times per second. When you hear a hum - the mains hum - it's either caused by magnetic fields from the wires causing the metal of the generator to vibrate, or it's caused by the wires in your speakers picking up the electric current in nearby power wires. | 34ab3b74-f76a-4766-9495-312012e27d3b |
cgytfi | Is urine beneficial or aggravating to jelly stings? | this is one of those cases where someone heard a fun factoid, and spreads it round without context and it now becomes a widely recognized "myth". There is a specific composition of urine that would work for specific types of stings but the chances that your/someone elses pee on the jellyfish that stung you would be a match is very very very low. For the times where Urine does not how, it can actually cause the stinger cells to release more toxins which is what causes the pain sensation. The pain lasts a long time because your body has its own natural defense mechanism but it doesn't work as fast.
& #x200B;
This is kind of like someone saying "i kicked my tv and it turned on again" maybe in very few cases that your kick shook something loose back into place but more likely than not you would do more damage than finding the right tool for the job. | b8abb6fe-20e6-4e36-ae10-4ab50461571d |
cgz6fw | Why is seawater green in some places, and clear/blue in other places? And why dont these colors mix? | Green sea water is usually the presence of floating algae, diatoms and other plankton that feed on the nutrients in the water. Green water has more stuff alive in it, usually colder water. Colder water can hold more dissolved oxygen in it. Often colder because of upwelling of deeper nutrient rich water that's being pushed to the surface by underwater geological features.
Tropical water tends to be clear/blue because it's warmer and therefore has less oxygen and have less nutrients, therefore less microscopic aquatic life. | f5923954-1bec-4554-bab2-90c3c35028da |
cgzd0x | How can earthquakes be "predicted"? | Short answer: They can't be predicted, only detected.
Medium Answer: You can sort of predict them on geological time scales (i.e. hundreds, thousands or millions of years) based on past patterns of earthquakes, but it makes predicting the weather next year look simple and reliable.
Long Answer: Monitoring stations all over the world exist to detect seismic activity (and nuclear weapons, but lets ignore that here). Sometimes earthquakes seem to come after a period of smaller tremors, but usually there is one major purpose for these sensors; giving a short warning. If you have a sensor very close to various faults or volcanoes, you can send a warning at the speed of light while the quake itself moves at the speed of sound through the ground. That can add up to almost no warning, or a lot of warning, but any warning is better than nothing.
Some plans exist to use these systems, or others which sense faster initial waves, to automatically engage certain safety systems. Power grids would "brace" for impact, trains would brake to a halt, and traffic lights would go red, automated warning evacuation warnings would occur. Even then, in the best circumstances, you're talking about minutes and not hours of warning.
This is one reason why earthquakes are so dangerous, because while you can build to withstand one, you can't predict them accurately in terms of time or intensity (on the scale of a human lifetime or two at least). | bf4b4238-28ad-4617-bcc6-8629a6cda970 |
cgzl85 | Why don’t our ring fingers have the same mobility as our other fingers? | [_URL_0_](_URL_0_)
Here's how the muscles connect to our fingers, I'll refer to that in the explanation here.
& #x200B;
If you look at the index, pinky, and thumb, you'll see that they have unique muscles attached to them that allow them to behave somewhat independently of the others. The ring finger doesn't, it uses the same muscle groups that activate the other fingers, so trying to get it to do something unique while the others are moving is just about impossible.
& #x200B;
There are exercises you can do to better control the ring finger, and musicians really enjoy these kinds of exercises because they give them better control over their instruments. | 412a554a-bb24-4351-b5f8-f83058b9b84f |
cgzuw8 | Why would a senator vote against the permanent funding for 9/11 first responders? | The bill was voted and passed 97-2.
The two senators who did not vote yes on the bill (Rand Paul and Mike Lee) both proposed amendments to the bill which were shot down quickly and the bill passed.
Rand Paul was doing obvious grandstanding quite a bit saying the bill is fake furor over a problem that has already been addressed (there are other bills already in place), and that the amount of money spent on this particular bill needs to be offset by other cuts, because the cost is too high and he doesn't want to increase spending/debt.
Paul Lee proposed a similar idea to limit the cost, which was also rejected.
Almost certainly, they voted no to get political attention and well, they certainly are gonna get attention from it. | 2465125f-02bf-49e6-a2ab-1c9eafd7987a |
cgzxjp | Body fat?! How does it dictate its destination?? | Fats you ingest are broken down in your body into glycerol and fatty acids using secretions from your fall bladder and pancreas before it is absorbed through the intestinal lining into the lymphatic system. The lymph system delivers the reassembled fat packages to veins near the fats destination. The fat packages are broken back down into fatty acids and glycerol in the bloodstream so that they can easily pass into cell membranes.
After that (extremely shortened) crash course into how far gets into cells, I can answer your question.
Fat doesn't dictate its own destination. Sex hormones do! Testosterone in low levels encourages fat to be absorbed into adipose cells (fat cells) in the belly and estrogen encourages fat to be stored in the hips, buttox and legs. Sex hormones don't directly control where fat is absorbed, but they trigger other hormones that tell fat cells to absorb fat.
The distribution of fat cells is controlled by sex hormones during development. When these signals are sent out for fat cells to absorb fat, because there are more fat cells in certain areas, these areas absorb more fat in total.
When a person gains weight, the fat cells get bigger, the number of fat cells does not increase. Where fat cells are created in development controls where a person stores fat.
Tldr: fat doesn't decide. In development, higher numbers of fat cells develope in different areas based on sex hormones I'm development. When the signal saying "store extra fat" is sent out, the most fat is absorbed into areas with more fat cells. | d6847cee-69ba-4912-a07c-f6ad8ca61dee |
ch0i16 | Is it possible that dinosaurs could exist on another planet like Earth | Technically possible but extremely unlikely that another planet would have nearly the same conditions and evolutionary path that would lead to dinosaurs existing. Actually, it's so unlikely that it is almost impossible. | 57f82578-2e94-41a6-b6df-a70944875778 |
ch0ib1 | What is that feeling called "when a vehicle beside you is moving, but you’re stationary, however for a brief second it feels like you’re moving if you look at the other vehicle and why does it happen? | A lot of the data your brain uses to control balance is visual. Try walking a balance beam with your eyes closed.
This phenomenon happens sometimes because your brain doesn't realize that the object it is using as a stationary frame of reference for your movement, is itself moving. Your brain really thinks you are moving backwards and can trigger the sensation. That's why this happens more if you are not paying attention to what you're looking at, and the car is a large portion of your field of vision. Without another object to tell your brain that the car is actually moving, for a split second it assumes you are rolling backwards. | 12abdbc1-3ab2-40af-aad0-c02ad3c9c8fd |
ch0r8k | - Why is some lightning not accompanied by thunder? | It is just lightning that is too far away for you to hear the thunder. It takes the right atmospheric conditions for you to see it. It is often called "heat lightning" but there is nothing different about it. | 38d852b4-bd8f-4570-9921-567e565d3eb1 |
ch0z62 | zoning out on drives | I will defer to a [previous answer](_URL_2_) to this question, courtesy of u/coriolinus.
> Driving is not an intense task. Once you're used to it, it is almost as simple as walking; you simply do not need to actually think about most of what's going on.
> Memory is triggered by novelty. If you see something new or interesting, you are more likely to remember it. Conversely, if you see something you've seen dozens of times before, unless something unusual happens you are unlikely to remember it. A person who drives 10000 miles per year, and has done so for the last decade, will have in that time spent around 2500 hours on the road. Truly novel experiences on the road will be very rare.
> In short, you are probably paying all necessary attention to the road as you drive. However, you don't bother forming memories of the experience because you have done it all before.
Or [another](_URL_1_) by u/dfoley323
> You\[r] brain will tend to 'zone out' on certain tasks that are done over and over again. Basically it tries to minimize sensory over stimulation.
> That's why you can remember an event (Omg a car just ran the stop sign and almost hit me), but you might not remember the make/model/LP unless you are trained or conditioned to force yourself to remember these details.
> For someone who has been driving a lot, most of what you are doing is basic motor functions; scan the road, move the steering wheel left/right to keep inside the line, follow the speed of the car in front of you. This is also why non aggressive driving people tend to run red lights.
And [another](_URL_0_) by psychologist u/\[deleted]
> Psychologist here. This happens for essentially the same reason that you Can "zone out" while you're walking around, not stumbling or colliding with things. These tasks are called "steriotypic repetitious movements" and they are actually controlled by a different part of the brain after you've fully learned the skill! When you start to learn any skill, like riding a bike, your cortex is the part of the brain doing the work of figuring out how to coordinate your muscles appropriately. Its complicated at first, and it involves your full attention, just like when you learned to walk. However, over time your cortex figures out exactly which muscles need to coordinate in exactly the right way, and it basically "saves" that motion in memory. When you go to do that action again after its already been learned (or saved) a cool thing happens, the cortex isn't nearly as involved anymore, now it's more subcortical (aka below the cortex, so deeper in the brain) regions that control the movement. The result? Now you perform an action while your cortex is free to think (or not think and "zone out") and forget you're actually doing anything complicated at all. | 9979c55e-7eeb-4893-b1d5-df14a7a01754 |
ch0zv9 | what does it mean by space is a vacuum | It means that a typical cubic meter of space has about 1 atom in it. The rest of it is emptiness. | 7b42039d-50bf-4eec-8940-1d8301788755 |
ch13yw | How does cardio decrease ones heart rate? | With extensive training, your heart will eventually get stronger and become more efficient at transporting oxygen to the rest of your body, meaning it'll require less pumps and lower one's heart rate.
I dunno about the second question, though. | 6f3dfd55-0da9-4d2b-a0ad-c24101862b02 |
ch1h1e | If falling asleep at the wheel is such a big problem, why don’t people just pull over to the side of the road and sleep in their car? | Because the road isn't necessarily a good place to nap. To start with, the shoulder of most roads isn't terribly large. Even on a major interstate highway you've got basically just enough room to fit your car. Sleeping that close to other drivers barreling past you at high speeds, is not a safe decision.
Up next, the kinds of sections of road where people tend to get tired, are relatively isolated. Falling asleep in your car, in the middle of nowhere can leave you in a fairly vulnerable position.
Finally, this behavior is likely illegal in a lot of instances. Stopping on the side of the interstate for instance is a problem unless you're stopping for an emergency situation (broken down, etc).
Even truckers stop at either truck-stops, or designated rest areas.
Edit: If you find yourself in this situation, stop in the nearest town you can find. Find a McDonald's or a Walmart parking lot. They'll likely be friendly (my local Walmart in particular is good about letting truckers and RV's part and sleep, provided you go to the far-end of the lot, and don't cause trouble. This is the safest option for sure. | 60f7bab0-d391-4d43-9d6c-26306ec48e79 |
ch1h7g | How do our bodies decide where to burn fat from after exercise? | They don't really decide. The fat on the surface of each deposit is metabolized with fairly equal preference. This means that deposits with a higher amount of surface area will lose the most mass.
Edit - In other words, it comes off in layers like peeling an onion. The top layer is burned wherever it is located on your body. | 66f83b92-a671-4194-82bb-341d24c0b8e6 |
ch1pi1 | Why do scientists assume water is necessary for all life on other planets? Is it silly to assume there might be other organisms that don’t need it to survive? | It's possible... Someone with more expertise can correct me on this, but water is just really useful, and is also a good marker of temperature. For one thing, it can dissolve all sorts of things. Like... especially with a little bit of the right additives it can dissolve darn near anything. Ex: Water with hydrogen chloride and nitric acid dissolved in it can even dissolve gold. This ability to dissolve things allows water to activate acids and bases, as well. Water is often called the "universal solvent" because of this. Now, because it is dense and viscous (when compared to gases), as well as good at dissolving everything, water makes it much more likely that life will form in the first place; the first life on Earth was single-celled organisms in the oceans. Lastly, if water is liquid, it indicates a temperature range that allows carbon-based life to exist. Carbon-based life is life that uses long chain molecules held together by carbon. Such molecules are often unstable at higher temperatures, and lose many of their interesting properties at lower temperatures. This means that too-hot or too-cold regions would severely limit the number of molecules life could be made from, which would make it even less likely to form. All of this adds up to mean that life (as we understand it) will likely form in and around water. | 60adee85-f709-47bb-bcd0-eb94e3717de2 |
ch1uc1 | What actually happens when water “goes down the wrong pipe?” | It enters your windpipe, which leads to your lungs, instead of your esophagus, which leads to your stomach. There is a small flap/valve that decides which pipe things go down, and sometimes you don't move it fast enough, our you for some reason try to breathe while drinking. Your body doesn't like that, so it causes you to hack and cough a ton to try to get it back out. A small amount of water can remain in your windpipe and lungs for quite a while, so you will probably have a good cough every few minutes for a while after the initial swallow. | aa0dc477-264e-4fd5-bb82-e9fd99ffc55d |
ch1vr5 | When lightning hits the water, what happens to the fish? | There was a question like this earlier. Mostly, the fish don't care because the lightening spreads out and dissipates enough to be safe before it reaches them. A couple of 'em will die occasionally, but there are plenty of fish to keep the population going. | 6d88e8cd-db62-4f4c-867c-24344e84822f |
ch2kdk | why doesn’t a plane fall from the sky when it turns? | The plane will always produce lift approximately perpendicular to its wings. If you bank (rotate along the fuselage) the plane then the direction of the lift will rotate the same amount and no longer point directly upwards but rather point somewhat in the bank direction. This results in 2 things:
There is now a force pointing in the bank direction. The plane will move in the bank direction and fly a turn.
The lift is no longer directly opposite to the force of gravity and thus the plane will start to drop. If you want to fly a level turn (compensated turn) you will need to increase your lift by 1/cos (bankangle). You can do this by pulling on the stick during the turn. | f6d315d4-96fa-44d2-acc2-e748eb03485c |
ch2m9u | Why do containers such as wine and beer bottles do the whole “glug glug glug” thing when being emptied? | Air displacement. When pouring a bottle upside down or covering the entire seal as it empties it creates a vacuum. The positive pressure from outside moves to the low pressure inside the bottle. | 606b91f6-abc3-43da-92ca-6d4e7de0768d |
ch2mij | What part of the brain is responsible for the 'internal monologue/dialogue' we hear in our minds? | Scientist have looked at brains using fMRIs and found the superior temporal gyrus and the left inferior frontal gyrus light up.
Those are the areas that light up deal mainly with language.
A bunch of other areas light up as well, a lot have to do with predicting what other people would do.
To put it to an analogy, it's a lot like GPU processing on a high end Computer.
There is some very expensive and very powerful specialized hardware installed.
It was meant to do one thing that was very difficult.
But in the process it turned out we could use that hardware to do some other things that were difficult. | 5a756b05-d5db-404d-b25e-ff560e156502 |
ch2plt | If the moon moves 1.6 inches every year away from earth, and is 4.2 billion years old, why is the moon not MUCH farther away? | Well, if it moved at a constant rate of 1.6 inches per year, after 4.2 billion years, it would have moved about 106,000 miles.
It's current distance from the earth is about 240,000 miles, so 4.2 billion years ago it would have been about 130,000 miles away.
As it happens, the rate at which it's drifting away is actually slowing down, so it was probably closer than that. | 453dbde3-2ea2-4e73-ad56-3d519f12945b |
ch2pt0 | Why do you see colors and distorted shapes when you have your eyes closed? | When you're eyes are closed, your retinas are still sensing even though they're not actually seeing anything. However, the only type of data that your brain can receive from your retinas is visual input, so the brain puts an image to what you're sensing. (You see more wild colors and images when you rub your eyes while closed, right? That's your retinas sensing changes in pressure and your brain trying to read what they're sensing.) | d7b7ec81-f02e-43a1-aab0-7eb01467d0ae |
ch2pzl | How do we know π is never repeating when could be just a really big series/pattern of numbers? | This is a bit complicated so I'm going to trh my best to break it down in a way that will at least give you something! I'm also not a professional mathematician (though I do have a degree in math). I hope this helps somewhat!
Irrational numbers are numbers that cannot be expressed as the ratio of two integers. This means their decimal sequence never ends or repeats. However, there are two major classes are irrational numbers that are each a little different.
The first are [algebraic numbers](_URL_2_), which are numbers that are the solution to some algebraic expression with integer coefficients. All integers and rational numbers are algebraic numbers as you can simply construct an expression such as m*x=n, therefore giving you solutions of the form n/m where n and m can be any integer. However, what is really interesting to us here are irrational algebraic numbers. The square root of two is an irrational algebraic number as it is the solution of x^2 =2. It can be shown that this number is irrational quite easily by a proof of contradiction shown [here](_URL_3_).
The second major class of irrational numbers are known as [transcendental numbers](_URL_4_). These are numbers that do not satisfy any finite length algebraic expression, and so they can be thought of as "transcending" algebra.
The [Lindemamm-Weierstrass Theorem](_URL_1_) allows for a proof that pi is NOT an algebraic number. The proof essentially goes as follows:
- First, it was shown the e^a (where e is the base of the natural log) is transcendental if and only if **a** is algebraic. (A sketch of this proof is shown [here](_URL_0_))
- Euler's identity is used to show us that e^(i*pi) =-1
- Because -1 is a rational number, then that means (by our first step) that i*pi is NOT algebraic.
- i is the imaginary unit and is algebraic (it is the solution to x^2 =-1)
- Therefore pi is not algebraic.
- If pi is not algebraic then it must be transcendental, and so it is irrational.
An interesting thing to note though, is that even though pi is transcendental and thus has a never ending non-repeating decimal sequence, it has NOT been proven to be "normal". What that means is that we dont know if every digit appears with the same regularity. If pi isnt normal, then it means that even though it is never ending and non-repeating, there are sequences of digits it would NEVER contain. As an extreme example to illustrate this: imagine that at somepoint, a trillion trillion trillion digits into pi, it stops containing the number 5. No more 5's appear. The rest of the digits (0-4 and 6-9) still appear infinitely and non-repeating, but you'll never get another sequence that contains a 5.
What this means is that those quotes claiming that pi contains every sequence of digits and thus contains the information for "anything and everythjng" aren't actually substantiated as of yet. If pi is normal then that would be true, however we just dont know! (And it should be pointed out that this property is not actually mysterious or unique. Most numbers are transcendental and normal. We just have a difficult time finding/proving them to be such because so much of our mathematical foundation is based around algebra)
**TLDR:** The basic idea is that it is possible to show that the number e is transcendental as it cannot be expressed as the solution to a finite algebraic expression. By using ruler's identity, you can conclude that the same must also be true for pi.
This is rather complicated stuff.... maybe someone with more insight than me can give a better answer, but i hope this helped at least a bit! Let me know if you've got any questions about this. | bc19cdb9-ab6d-4caa-8afa-458b8a68514c |
ch2reh | What is code and why is a lot of it in 0’s and 1’s? | This is a really complicated question, but I'll try to answer it as briefly as I can.
Your computer is very much a kind of electrical machine, that manipulates the voltages of different wires, and is designed to preform calculations on those voltages. Scientists realized pretty early on in computer science, that a simple cost effective way to build computers was to use only two different voltage levels to represent different values, a high level and a low level.
With just two voltages, you can represent numbers by encoding them into a number system called binary. In binary, we use the number 0 to represent a low voltage and 1 to represent a high voltage. With just one digit you can only have two numbers 0 and 1, but if you have more digits then you can have bigger numbers. In binary 0, 1, 2, 3, 4, 5, 6, 7... gets converted to 0, 1, 10 (we added another digit for 2 because we ran out), 11, 100, 101, 110, 111...
Once you can represent numbers in a computer, you can store other kinds of data by mapping the numbers to a code. For example if you want to represent the alphabet, you could make 0 a space, 1 the letter a, 2 the letter b, and so on. It's a code because the numbers represent something else, like letters.
You can also represent computer instructions in a code (called machine code) and then you can design chips that read that code and execute those instructions. A chip that does this is called a processor, and the instructions it runs is called a program.
You can also represent letters, and this kind of code is called an encoding. ASCII and ANSI are some simple encodings that you can use for English, and UNICODE is an encoding you can use for any language.
You can also write letter codes that convert to machine code. This kind of code is called an assembly language, and a computer program that converts assembly to a new program is called an assembler.
You can also write more complicated codes that you can use to create programs. This kind of code is called a programming language, and there are thousands of different programming languages with different levels of complexity. If someone says they are a coder, they probably mean that they write computer programs in a programing language.
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The 0's and 1's in the machine, by themselves are totally meaningless, and it's the machines ability to read those numbers as machine code, process those numbers with computer programs, or to convert them to a different format with encodings that make them useful. The computer can also just read them as binary numbers if it needs to, but binary is still a 'code' of sorts (called a number system) that converts those high and low voltages into numbers. | a543d9b7-59a5-4c97-9980-aec651a8568a |
ch2sit | Why do companies buy our information and how is it valuable? | Same answer to both questions - because they want to sell you stuff.
Computer software has advanced to the point that crunching enormous piles of data and getting real actionable insights is pretty easy. As an example - Target's analytics were so good that they started sending maternity oriented coupons to a 16 year old girl. Her father sued the company... only to find out that the girl was in fact pregnant. *They figured it out just by looking at what she was buying.* | 156c3132-3c66-4bcb-8a71-e4de9aeb6c74 |
ch32ll | what makes leopard and jaguar different | Elephants are the only animals of their kind, leopards and jaguars are not the only animals of their kind, they are part of all the big cats. Elephants are so similar that all are called elephants. Leopards and jaguars are actually not as similar as you think, they just happen to look the same. | 9eb10735-9cf0-4444-be5d-265781de7d58 |
ch331p | What major changes would occur if Earth started spinning at 25 hours/day? What about 23 hrs/day? | Welp, nobody else has answered so I'll give it a go - I'm no climatologist tho. It sounds to me like you're asking specifically about how such a change would impact *climate*. With a slower spin, days would get hotter, and nights would get colder. It would be gradual, but the more you slow the earth the more you ruin farmland. These temperature extremes would force rapid adaptation on ecosystems and the life within them, and anything that failed this trial by fire would die. If I had to guess, I'd say that this would begin to happen within an extra 2-3 hours on a day, but I really don't have any good information to judge off of. Every creature with a circadian rhythm would be very confused, as well, since we're used to a particular length of days. If the Earth sped up, the opposite would happen. Day and night would get more similar temperatures. The Earth would probably heat up slightly. That's all I can think of tho. | ccefe1d5-68c0-4340-9bd8-f4eef8bdf0cc |
ch33u9 | Where did the original vinegar "mother" come from, if you need vinegar to make a "mother"? | Vinegar is Latin for “sour wine.” All you have to do is let wine go bad under certain conditions and you’ll get a mother eventually. | 2326df18-a92c-4894-bed0-e412728de546 |
ch34wm | If two separate plant's light sources are exclusively lightbulbs of equal lumen outputs but one bulb is LED and the other is incandescent, will they both photosynthesize / grow at the same rates? | From a quick google. Yes leds can be used as grow lights. They’re actually beneficial because you can customize the “spectral intensity” to suit different stages of growth. | ad711003-33c4-44ff-b97b-c688cdc2b8fc |
ch3i76 | Why do Composite signals look so good on CRT's but utterly horrible on modern LCD's of the same size? | Because w/o having pixels, a CRT display isn't able to produce images as sharp as the ones shown by the LCD. The CRT smoothes the image and hides out some of the image defects, if there are. The pixels you can notice by looking closely to a CRT are just a regular pattern on the screen mask between the screen and the three electron guns. | 17154a4a-ee9d-4fb3-92e9-9970fecf8938 |
ch3ka9 | how come a camera can pick up light on a TV remote when being used but you can't see it with your own eyes? | Cameras use a different system to detect light than our eyes do. Our eyes use rod and cone cells and some weird chemistry stuff. Cameras use various systems - one example is photodetectors with filters over them to select for colors. This system is designed to replicate our eyesight's frequency range as best as economically possible. Emphasis on *economically*. To mimic our eyesight perfectly, the filters' frequency transmittance range has to match our cone cells' frequency sensitivity. The better this match, the closer the similarity a camera's picture is to what we see. Typically, they use the standard of "close enough" and call it a day. As such, a little bit of infrared light slips past the filter, and the camera sees it. | 589d873d-9ac3-4f1e-8016-75ddac54555d |
ch3mf4 | How do just a few satellites give the precise location of a million of connected devices at the same time? | Each GPS satellite just broadcasts where they are, and what time their clock says. That signal can be picked up by any number of devices that have line of sight to the satellite.
The devices can then determine their position by trigonometry. Radio waves travel at a constant speed, so if you pick up a signal, and you know when the signal was transmitted, and what time it is now, you can determine the distance to the transmitter. With multiple signals from known locations, you can determine your own position. | 70ad1532-c2c8-4d25-a55d-317f59bc9824 |
ch3qsy | How has Jupiter’s red spot been such a large and powerful storm for centuries? | Storms are sustained by the conditions of their environment and the spin of their planet. So long as the planet keeps spinning and the conditions stay (normally, a hot center and cold exterior), the storm continues. | 72ec0702-90a7-4864-9890-2695af5bd181 |
ch3xbb | What part of physics (QED, GR, etc.) predicts the existence of different phases of matter? | The work on phases of matter exists in the mathematics of statistical mechanics, which is used heavily in solid state physics, condensed matter physics, materials science, and a lot of chemistry. | c10b3d99-3dcf-49be-8f7e-ded10bce3348 |
ch44x3 | How does this image have lines from the TV on it that change depending on zoom? | It is called a ["Moire pattern"](_URL_0_) and it happens when two regular patterns don't sync up leading to patches of interference. This is very common when taking pictures of digital displays as the pixel grid of the display is unlikely to match up with the pixel grid of the image capture device. | 90661b7c-bfa6-4500-9885-4344fe8f7dee |
ch4o08 | why Americans are more used to air wents on a floor for heating their homes and Europeans are using radiators and floor heating? | We do also have floor heaters and radiators if it’s an older home, but since have moved to forced air systems. Cooled and heated air can move through the same vents to get to the rooms from the unit. Since the units are usually in the basement imagine the system being a trunk of a tree, and the vents are the tips of the branches coming off of it. | 7115b527-8527-4c4f-bc30-4ec10097869b |
ch4s6j | How do some animals, such as scallops and clams, function without organs? | Your premise is totally wrong. Scallops and clams absolutely [have organs](_URL_0_). Even if you weren't wrong about, there are still other organisms without differentiated organs. I mean, all bacteria have no organs. They're just single cells. Less complex life forms don't need specialized organs for things, so their anatomy is likewise less complex. A jellyfish is basically just a floating sack of water. It has only the most rudimentary nervous system, a stomach, and a sex organ, because that's all it needs. | d90f7081-3273-4575-a5e5-690e18385046 |
ch4soc | How can something be 46 billion light years away from Earth, When the age of universe itself is 13 billion years? | The universe is expanding faster than the speed of light.
[This video](_URL_0_) goes into how the universe can expand faster than the speed of light and personally I find it easy to follow.
The basic explanation is that the speed of light limit does not apply to the expansion of the universe. | 5a70f32c-6daa-4f6f-9624-8a5f3e929ea3 |
ch58p8 | Could Queen Elizabeth refuse to accept a Prime Minister? What would happen if she did so? | The Queen has to decide whether the proposed new PM "commands the confidence of the house" i.e. could the PM lead a functioning government.
The Queen can quite legitimately send the proposed PM away if she thinks that a functioning government is not possible, but in reality this will never happen because:
1. The decision is made before the new PM goes to Buckingham Palace, the Royal Household will be kept informed of what is going on so the process won't go ahead if there is any doubt.
2. The new PM is "invited to form a government" so they have time to go away and sort out the details. In 2017 this involved Theresa May negotiating with the Democratic Unionist Party to get a theoretical majority in the House of Commons. In 2010 it involved the Conservatives leading a Coalition with the Liberal Democrats.
3. There is a very high risk of a constitutional crisis if the Queen actually exercises this power. In reality she knows that a non-viable government would be brought down by a vote of no confidence in the House of Commons. This is the proper way to resolve the situation.
Ultimately Parliament is sovereign, the Queen is an important part of the process, but if she tried to interfere then it would bring about a national crisis. | 56a465e3-4919-4120-b400-b761f2a2d38e |
ch5k3b | how do ads load on bad service but normal content doesn’t? | Youtube (through Google) have many, many servers across multiple regions of the world to store their data. Very popular content may be hosted on multiple servers to constantly have it closer to the viewer, and on faster servers.
Less popular, more normal content will not necessarily be copied on multiple servers, or stored on very fast servers, making the video load more slowly.
Ads, on the other hand, will be stored in servers geographically close to you, and fast enough to always let them play as smoothly as possible. | d6581c1d-b016-4ad3-9555-99fc67104cab |
ch5k58 | What is brain plaque and what can happen if it is not taken care of and how can it be prevented? | Alzheimer's disease involves amyloid plaque. No one quite knows why, although there are theories. [For some reason, amyloid protein breaks down and forms "plaque", which are blobs of goo that the brain can't remove.](_URL_0_) Alzheimer's also involves tangles of Tau protein, which is a structural support that gives brain cells shape. It isn't really understood whether the amyloid plaque or the tau tangles are the *cause* of the disease, or if they're more of an effect. Billions of dollars were spent developing and testing drugs that broke down amyloid plaque, they failed to help people with the disease.
[The best thing to prevent it is sleep.](_URL_1_) Also, floss your teeth- [gum disease is lined to AD](_URL_2_) There are multiple hypotheses on how gum disease is linked to AD, and why it doesn't happen to young people with gum disease, but it is safe to say that flossing lowers the odds of developing brain plaque. | bee87756-4277-4d4f-8d5e-8fd4dbc14863 |
ch5nhr | Why is the magnetic North Pole moving faster than the magnetic South Pole? | I am not a geologist, so i will try an explanation based on physical and mathematical intuition:
The south magnetic pole (SMP) lies significantly farther away from the geographic south pole (\~2800 km) compared to the north magnetic pole (NMP) which lies \~600 km away from the geographic north pole. Given that Earth is an oblate spheroid, it doesn't have the same radius everywhere, it increases as we move towards the equator. This means that the SMP is farther away from Earth's core. The polar shift happens because of fluctuations in the flow of molten iron in Earth's outer core, which causes changes in Earth's magnetic field. Now the strength of a magnetic field is inversely proportional to the distance from its center. Less force is exerted to particles farther away from the center, therefore their acceleration and speed will be smaller. Thus the SMP shifts slower than the NMP.
Again, this is my interpretation and is open to debate. | 8256f45b-df17-466a-8ef3-6d84c47b4702 |
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