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cg9wu9 | How is the Riemann Hypothesis linked to our understanding of prime numbers? | The Riemann Zeta Function encodes information about primes and their distribution. Essentially, every prime contributes a factor to the value of the Riemann Zeta Function weighted by how big the prime is, and different inputs to the Riemann Zeta Function weight them differently. So an understanding of the Riemann Zeta Function as a whole can, theoretically reproduce information about primes. For instance, the fact that the Riemann Zeta Function is infinity at 1 implies that there are infinitely many primes and says a bit about how they are distributed along the number line.
So on one hand we can view the Riemann Zeta Function as wholly constructed from the prime numbers. On the other hand, the Riemann Zeta Function is what we call an "Entire Function" (well, meromorphic). One key thing about entire functions is that they, in some ways, behave like "infinite degree polynomials". What this means is that, like polynomials, they are almost completely determined by where they are zero. This means that the Riemann Zeta Function is almost completely determined by where it equals zero. Some further analysis of the function constrains the (meaningful) zeros of the Riemann Zeta Function to all having to live in some vertical strip on the Complex Plane, called the Critical Strip.
So, the Riemann Zeta Function is completely determined by the primes and completely determined by its zeros. That must mean that we can use the zeros of the Riemann Zeta Function to get new information about the primes! And this is true, we have [formulas directly relating the primes to the zeros of the Riemann Zeta Function](_URL_0_).
For instance, the Prime Number Theorem was one of the biggest open questions in math during the 1800s. It conjectured that the number of primes less than a number x was "about" x/log(x) (where there is a technical condition for "about"). This was very hard to prove. But Riemann came along and proved all this stuff about the Riemann Zeta Function and showed that if we could prove that there were no zeros on the edges of the Critical Strip, then we would get the Prime Number Theorem. There was still a ways to go, to make Riemann's analysis rigorous, but eventually the Prime Number Theorem was proved using this strategy.
Riemann noted that the closer to the center that the zeros were in the Critical Strip, the more "nicely" the primes would be distributed. So he conjectured that all the zeros would lie exactly in the center of the Critical Strip. This is the Riemann Hypothesis and is one of the most important open questions in math today. | 88fa6796-d9b7-48f3-b183-376c2ebead84 |
cga9zi | How did the tip culture in America become so prominent + the unwritten rules for tipping. | In the mid-1800s Americans discovered tipping habits in Europe and brought them back to America. Shortly thereafter Europe ended their tipping tradition but it was just picking up steam in America. It may have died out after a couple decades if nothing drastic had changed (because tipping was seen as elitist and was outlawed in a few places because of that), but in 1870 the slaves were freed by the 15th Amendment (of the U.S. Constitution).
Slaves now were free and they needed jobs that didn’t require much education. They got jobs as waiters, servants, barbers, railroad porters, etc. These were pretty much the only occupations available to them. Employers found that it was more profitable to literally not pay former slaves anything ($0) and simply required customers to leave a small tip after the former slaves performed their service.
Eventually race relations in the U.S. evolved but tipping laws never did. In 1938 Congress finally passed a law requiring employer wages and tips to add up to an hourly minimum wage. So if you only earned $1 in tips and minimum wage was $3 an hour, your employer would have to pay a tipped worker the other $2. This is still the law today. | b1066614-71fb-4c57-bb5d-014e517ab8d3 |
cgads1 | Why do birds, tiny beaked dinosaurs, find humans relatable enough to seek attention from us when they're in captivity? | Most birds aren't that smart but most animals can recognize familiar faces, even tortoises and small fishes which are both way dumber than most birds can do this, if an animal grows in captivity they will develop a kind of affection towards its ~~overlords~~ caretakers, or at least they will associate them with food, comfort and similar feelings which can make them look affective towards them.
& #x200B;
As as side note some birds like parrots and crows are actually very smart and can very easily recognize faces, remember people, solve puzzles and problems and crows can even use tools. | 5d1882fc-5c2a-41a9-b5c8-4c83316cd5ff |
cgadst | How do scientists measure the depth of an Earthquake? | The basic idea of it is that they use the timings of the seismic waves generated by the earthquake to locate where in the Earth’s crust it originated.
To explain a little further, there are several different types of wave produced by all earthquakes set apart by the type of movement they create. Of importance here are P-waves (primary) and S-waves (secondary). As you would expect from the names, P-waves travel fastest and arrive at seismometers first, S-waves the second fastest and these arrive next. You can also think of the letters as standing for pressure waves and shear waves due to the way they move through the Earth [which is illustrated here.](_URL_2_)
The epicentre can be roughly triangulated using the difference in timings of P-wave arrivals at 3 or more seismic stations so that an epicentre closest to station A, then station C, then station B is [illustrated here](_URL_1_).
Note that the epicentre is just the bit of surface ground where the origin first reaches though (directly above the origin). What you are asking about is known as the focus or the hypocentre of an earthquake (they mean exactly the same thing, but geologists like having plenty of words...). For this we need to get a bit more clever and use the pP-wave too, which is a P-wave arriving at a station *after* it has already been reflected off the surface. It’s a bit tricky to explain without a diagram so [here you go](_URL_0_).
The depth of the focus can be found by measuring the difference in arrival of the P-ray and the pP-ray. To give you an idea of how it varies - for a series of earthquakes occurring at progressively greater depths below the same epicentre, the pP–P difference would increase. Another method is where seismologists use a mathematical relationship relating depth to P-wave arrival time to turn that triangulation method earlier into a good approximation for the focus (instead of just the epicenter), when done for several different arrival times at stations.
It can take several days to get the best possible pinpoint on an earthquake focus because different combinations of these methods are used and results are refined as the signals are gone over in detail (half the job is separating out the necessary waveforms from seismograms) and collated with data from seismic stations over a large area. | b663fcf2-c47e-4fc5-999c-c60d7872cbad |
cgafjg | What causes sea sickness, and is it related to motion sickness? | Yes. Sea sickness is kinda the opposite Version of car sickness. It's caused by a disassociation between what your eyes see and what your balance organ in your inner ear feels.
When you're on rough seas inside a cabin, your eyes see no movement. To your eyes you're in a stationary room, but your balance organ can feel the ship swinging back and forth on the waves and this disassociation is what confuses your brain and makes you sick. As opposed to car sickness where your balance organ feels you're stationary, but your eyes see you moving along through the window.
The most popular hypothesis is that the sickness itself is an evolutionary response, as certain poisons or toxins can also cause such a disassociation. | e5acdc46-43ed-4a61-a6d8-68d84555bf46 |
cgagmg | What exactly was the watergate scandal and why did it kick Nixon out of office? | Nixon's goons were caught red-handed breaking into the Watergate hotel to steal files from his Democratic opponent.
Recordings Nixon himself made in the oval office later proved that he personally ordered the break-in.
When the Supreme Court ordered the recordings released, the GOP controlled Senate told Nixon they would vote to remove him from office after he was impeached, so he resigned and was pardoned by his successor. | b228b190-d95e-4cc2-986f-35e4d6414a60 |
cgai01 | How do lasers work? | It depends on a particular way electrons can be arranged in an atom to store energy in the electrons in atoms and release it all together. Most materials don't emit laser light but simply give out random light photons when excited by heat or high voltages,
Think of it a bit like a set of high shelves while you are tossing balls into the air. If the shelf is just right compared to the others, balls that fall onto it stay there instead of falling down randomly as normal. When a ball hits one on the shelf, all fall down together. That's not an exact analogy but gives a ELI5 picture. | 734dcfd1-f3b4-4718-97a4-b52c1d3438e2 |
cgaiep | How are chameleons able to change colors to blend in with their surroundings? | Chameleons mainly use their color changing for communicating mood, and in response to temperatures, sorta like how you might change your face color to red when cold or angry.
Chameleons have light bouncing crystals in their skin.
They have tiny muscles attached to these crystals and can move them around.
When the distances between the crystals change the way it bounces light changes.
The different distances mean they bounce out different color light. | c21d00e8-5c81-4b90-becf-347095917c75 |
cgamq7 | What causes moles? | A mole is the result of one specific patch of your skin deciding that it needs to release as much melanin (skin darkening pigment) as it can. This is usually due to a benign tumor made out of melanocytes (cells that make melanin) forming under your skin. Most moles aren't cancerous and don't get worse over time.
If a mole changes size or shape over time, is bigger than your pinky nail, or is an unusual colour (especially more than one colour), you should definitely get it checked out. | 393dc571-463f-4f0b-8702-e574a9f41c2c |
cgarsz | how can a balloon deflate over time when there's no hole to let the air out? | For things like rubber balloons, the material is like 99.9% impervious to gases like helium, but not 100% so over time it just very slowly leaks through. | 425570eb-0565-4890-8533-64ba9c31ed80 |
cgasxk | If natural satellites (moons) are remains (or even consequences of collisions) of our planets, why do the orbits of the majority of them stay in the same plane as the orbits of the planets? Couldn't they be random? | Most moons don't actually orbit in the same plane as their parent body. Our moon, for example, actually orbits with about 5 degrees of inclanation.
But yes, generally speaking, they will adopt a similar orbital plane, and the reason for this is that when all this ejected material slowly gravitates towards other particles and collides with them, they cancel out in their vertical momentum. Similar to how the protoplanetary disk around our sun started out as a cloud, but over time flattened into a reletively flat disk. None of the planets occupy the exact some orbital plane because this cancellation of vertical momentum was not consistent across the entire disk, but is "close enough" to have similar inclinations. | 4a7e941c-3575-4ba2-be26-e78f7f86333d |
cgavme | Why do intrusive thoughts occur? | Thoughts are literally only limited by your imagination; if you can think it there’s a good chance you will think it at some point. In that way thoughts can be meaningful, meaningless, useful, benign and painful and every iteration in between.
Sometimes we are really good at letting random thoughts come and go through our head without thinking too much about it, but other times thoughts can be perceived as threatening.
When a thought is unintentional and perceived to be threatening (even strongly unwanted), we call it an intrusive thought.
We’ve all had the experience of an upsetting thought enter our head. Take for instance the thought “if I step in front of this train I will die”, now just because I have had this thought doesn’t mean it represents my intention (it doesn’t btw). Thoughts aren’t facts. However, it is an upsetting thought. Now when these thoughts don’t represent our intentions, most of the time we can just let them come and go without being too bothered by them. Occasionally though, the thought can be so bothersome as to be perceived as threatening, subconsciously I might think “this thought is dangerous, if I keep thinking it I might actually step in front of a train. Therefore I cannot think it anymore.”
The brain has now identified the thought as threatening, and does what it always does with threatening things- vigilantly keeps an eye out for them. But a brain being a brain, it doesn’t have to look far to find the threatening thought: “I must not think about stepping in front of a train... oh no I just thought about stepping in front of a train... I did it again, I must stop thinking about stepping in front of a train...argh!”
You see the problem right? If I tell you not to think of a pink elephant, what are you going to think of? If you try not to think about something, you’re going to think about it, that can feel threatening to us; the perceived lack of control of intrusive thoughts can amplify the level of threat that is perceived.
When people feel very threatened by thoughts they are having, it is likely they will feel very anxious too.
Eventually, you can come to associate the intrusive thought with all these things; the attempts to not think about the thought, the feeling of being out of control, the anxious feelings. So guess what, now it works in the other direction and each of these experiences can become triggers for the intrusive thought.
The good news is that we often can make intrusive thoughts less bothersome. It involves reminding yourself that thoughts aren’t facts. It involves accepting that upsetting thoughts will come and go, and that you don’t need to do anything with them. When we truly embrace the idea that these thoughts will happen and that they are not inherently dangerous, the irony is that we are likely to have fewer of them, and be less bothered by them when they do occur. | a2d6e0e0-cbf4-494b-bdb1-45eed3cbc8b3 |
cgay0h | Why are sweeteners in soft drinks very common (Diet Coke/Coke Zero for example), but not in other sugary foods such as chocolate bars, cakes or candy? | The same "zero" calorie sweetener you taste in a diet soda would taste drastically different if raised to a baking temperature prior to being served. Here is a good article detailing the whats and whys of how substitutes work in food prep: _URL_0_ | edae677d-1c9c-4649-8e95-7754847019ab |
cgaz03 | Why is a high note and a low note still considered the same note in music? | It is down to physics. The frequency of a given note doubles each time you go up an octave. Picking the note A because the maths is easy, the frequencies in hertz of the A keys of a piano are:
27.5, 55, 110, 220, 440, 880, 1760, 3520
We perceive this array of frequencies as the same note because they stimulate our senses in very similar ways. Unless listening to a pure tone, instruments will generate different harmonics as well as the fundamental frequency. It is the strength of these harmonics that we perceive as tone. | adfe4864-5066-4324-b481-5c1a7e3270a2 |
cgb7hf | What makes a helicopter go forward? I know the main rotor generates lift and the side facing one on the tail keeps it from spinning out, but what allows it to move forward/tilt different directions? | The angle of the blades of the main rotor can change mid-revolution, so that they can be more flat at the front, and at a higher angle at the back, creating more lift in the back and tilting the entire helicopter forward.
Helicopter pilots also have another control available to them: the collective, which changes the average pitch of the rotors, allowing them to control lift. | 84e882d2-1d2f-4155-9853-5bda14555817 |
cgbjp7 | How come metal is cold in room temperature? | Metals are generally good heat conductors, and your body is generally warmer than room temperature. So the metal conducts heat away from your body.
_URL_0_ | 4ba219c8-e8be-4107-bb56-32151a40f222 |
cgbk4t | What are “subliminals” on Youtube and do they work? | Subliminal advertising was a theory which was proposed that if you showed one or two frames in a larger film it was past before the conscious brain spotted it, but the subconscious brain would spot is and then be vulnerable to the influences of the frames such as being thirsty. However the initial research on it was faked and it appeared in the numerous places including an episode of Colombo before it was known that it was junk. | 23130d3a-d3ad-4de3-ae06-8953a2fe91be |
cgbq69 | How does a housefly react so fast? | Compound eyes allow it to see in many directions at the same time. And with it's tiny body and short neural pathways. Reaction time is very quick compared to a humans. | 6ec6d403-c544-47bc-9cb0-206e68f9e72e |
cgbr8q | How does a Bill get passed in both the House and Senate (explain differences in approaches as well)? | Generally speaking:
- The bill will be drafted by a Congressperson or a group of Congresspeople
- The bill be will be discussed in committee, where it will be amended
- The committee will vote to bring the bill to the floor
- The bill will be brought to the floor for debate, where additional amendments will be discussed
- The bill will be voted on
This exact same process happens (more or less) simultaneously in both houses of Congress. Assuming that the bills are passed by both houses, the bill then goes to a conference committee, where differences between the two bills are resolved so a singular piece of legislation is drafted.
Once this is done, the conference bill is sent back to both houses to be passed again. This singular bill, once passed by both houses, is sent to the President for signature. Once signed, it is law. | 25238232-8da6-43e1-8b93-81004d6ac88b |
cgbubp | How do songs/poems get translated into a different language? | So, there are (in general) two ways to translate structured language (i.e poems and songs)
a ) You can change the meter, but preserve the wording.
b ) You can change the wording, but preserve the meter.
If you just translate it as directly as you can then no. the beat, rhythm and rhyme will change.
If you try to preserve the meter you're going to have to change what words you use, find equivalent words that rhyme, have similar beat lengths, and convey *similar* meaning.
A poem can easily have the same meaning if all the words have been changed (imagine replacing all the words with synonyms), but it's the job of a very skilled translator to do this well over the course of an entire poem. You're going to loose some of the nuance, and the meaning might slightly be altered, but a skilled translator knows what meaning was being conveyed and can try and craft a new poem with *similar enough* meaning that it passes general interpretation.
You're probably never going to get an exact 1:1 translation of meaning simply because languages are different and convey different meanings under different cultural contexts: but you can get pretty close if you're good at your job. | 5ea56343-f685-4a0d-bf58-3ae94066941f |
cgby35 | If animals (humans included) are never exposed to the knowledge of their predators, would they be afraid of the latter? (eg. If a mouse was raised in solitary, has never seen a snake, how would it react? Is the instinct to escape innate?) | If you see a picture of a fictional monster you instinctively get scared of it. Even though you have never seen anything similar before. There are certain features in animals that we instinctively fear. First of all it is any creature bigger then us or at least looking stronger and more agile then us. And secondly you can often see it in the eyes and facial features if it is a predator as the eyes required to hunt pray is very different from the eyes required to spot predators. | a374762d-bd1a-406b-90ed-787f2621caec |
cgc4rd | How do foreign exchange rates work? | Although purchasing power parity suggests that MUA = MUB, this is a very long term equilibrium at best.
More important for the short term is the demand for currency. If MUA exports a lot of product while MUB does little export, there will be more demand for MUA than MUB. (you need to purchase MUA to buy product in country A to export). If there is larger demand for MUA then it will tend to appreciate.
Other factors include inflation expectation. If country A is believed to have a high inflation rate, then MUA will depreciate (fewer people will want to hold it) Often inflation expectations are also an assessment of the "risk" or "creditworthiness" of a country - if people believe the government of country A will print money, they won't hold MUA. | 323d47b0-e758-454a-b7e3-6ca4ef92be8a |
cgc5oc | Why do different compounds give certain colours when burned? | Burning involves putting heat, which is energy, into a compound. At an atomic level, when an atom receives energy, the electrons get "excited". Electrons, roughly speaking, "orbit" the nucleus of the atom at a certain average distance away. When they get excited, they "jump" to a higher energy level. Imagine jolting the Earth with a lot of Energy and, poof, it suddenly is in the same orbit as Mars.
The electron immediately wants to jump back down to its original level, but that means it would have to get rid of this energy, which it does, in the form of a photon. The specific "distance" of this jump determines the energy, and therefore frequency, and therefore color, of the photon.
I put a lot of words in quotes because electrons don't neatly orbit nucleus like planets do and a lot of quantum stuff can happen that is counter intuitive, but this is the ELI5 version. | e4475fbf-13d6-4f34-a574-7a7406fcce40 |
cgccnq | What is stochastic trend? | Let's use the example of the idea that "The population of the United States grows at 1 million people per year."
The simplest interpretation of this is a completely deterministic process. If the population last year was 325,570,271, then the population next year will be *exactly* 326,570,271. If you plotted US population over time, it would be a perfectly straight line.
A more complicated (but realistic) interpretation is that there will be some "noise" in addition to this growth. Every year the population will go up by about 1 million, but not exactly. If you plotted the population over time, it would look similar to the straight line from before but with little deviations each year. This would be called a "deterministic trend". There's random noise, but the trend itself never changes.
Even more complicated, you could think that the trend itself is changing randomly over time. It starts out at a growth of one million, but it may fall to 0.9 million the next year, then 0.8, then back to 0.9, etc. This is different from the randomness above because once the trend has fallen to 0.9 million, observing 0.8 million the next year is more likely and observing 1.1 million is less likely. You will still expect that over a long period of time, the average growth will be 1 million, but the line in your time series might spend substantial periods either flatter or steeper than that average level of growth. Because the trend itself is subject to random fluctuations, this is called a "stochastic trend". | 69e96e1f-2bcd-47fa-9c68-067c4070d3ff |
cgcdf7 | the current situation in Hong Kong. What is the desired outcome of the protests and is there a reason it’s all happening at Yuen Long | I think the general idea is "less chinese oversight and involvement into Hing Kong affairs." The Hong Kong people lived as a separate territory for a long time, and some of them get upset when China takes away their personal freedoms, etc. That doesn't mean they all want to be separate, because many of them have family in China, and they feel culturally Chinese. It's a complex situation that really takes a good understanding of Chinese history and culture to fully grasp.
The location "Yeun Long" I don't know why. Perhaps it's a good spot to get attention; the purpose is to be as visible as possible. | ea687b25-6086-4367-a6d2-4bf9937b62bd |
cgci6l | What is the spatial and temporal domain part of ? | Combined, the spatial and temporal domains make up space-time, a four dimensional void where objects can be created in three dimensional space over a period of time.
Einstein theorized that time is, in essence, a physical dimension and capable of being stretched and molded by gravity, leading to the idea of space-time being like a fabric, deformed by large planetary and stellar bodies. | 0d1103b2-4635-4454-bf13-4182a0cddf29 |
cgcicc | how does water put out fire? | Fire needs three things: oxygen, fuel, and heat.
Liquid water removes two of those things. It displaces oxygen and smothers the fire, and it absorbs the heat as it turns into steam. | c497f6e5-a3b9-471a-8910-c4e4557c6982 |
cgcuff | How do we keep in contact with spacecraft such as Voyager 2 that are at the very edge of our solar system? | With very big dishes on Earth, and very sensitive receivers that can find the tiny signal.
Fun fact: the Voyagers' radio transmitters are 20 Watt -- which is the same power as the bulb in your refrigerator.
So we're effectively looking for a flickering fridge bulb, 19 billion kilometres away... | 45c3ea98-2e67-46b1-8882-2ce26cd1791e |
cgd2p5 | How does your brain decide what's worth remembering and what's not? | This is a rather mind boggling question when you think about it.
The immediate answer is your brain *doesn't* decide what is worth remembering or not. A memory can be made more strongly depending on the context. More emotional or impactful memories will be burned it deeper. You can also decide that something is important and take conscious effort to repeat and recall it, which makes the memory stronger.
But, any decision you take is, in fact, your brain making a decision! So this question can also be stated: "Why do we decide to remember some things over others?" And that basically devolves into individual personalities and how the brain results in emergent consciousness, which we don't fully understand. | a7692a04-a338-474d-8db1-ecaac0ca2361 |
cgda8i | Why do people with arthritis experience worse symptoms when it rains? | At standard air pressure, your body is being pressed in on all sides by 6.7kg per square inch. Rain is usually preceded by a drop in air pressure. For the average person, this drop is not an issue - we've had millions of years of experience with it - but if you have inflamed tissue, like you get with arthritis, it is possible that the slight amount of soft-tissue expansion aggravates the nerves in that area... not enough to hurt you if you don't already have pain, but enough to \*increase\* existing pain.
The drop in air pressure is usually followed by a drop in temperature. This can cause stiffness, as tissues contract - part of the body's way of regulating temperature; contraction of blood vessels reduces the amount of warm blood being delivered to tissue - and might further aggravate already-inflamed nerves.
If those sound like hand-wavingly vague and possibly conflicting reasons, that is because there has been no definite medical correlation between rain and arthritis pain. For every study that finds one possible mechanism, another study finds the opposite. But there have been no large studies... people with arthritis don't get out much if they can help it.
Having watched the crippling effects of arthritis with my grandparents, and with an uncle who committed suicide when his arthritis got so bad that he could only walk with two canes or a walker at age 40, I've seen too much to discount the effects. But I also live where it rains a lot, and I've noticed that everyone gets a little crankier when the rain comes, and if they were already cranky to begin with they just get that much worse... it is possible that there are secondary effects that make the whole issue easy for medical researchers to disregard. (Like: "you're depressed and in pain? Let's work on the depression, see if the pain goes away when the depression goes away." But what if the depression never goes away?) | 7a974aa8-c0d2-4b90-935b-0ef668e6435f |
cgdbg2 | Why do some animal species end up being strictly carnivores or herbivores? | You need special teeth, bodyplan, and digestive adaptations for what you eat. If an animal finds itself in a situation where it is only eating one food (for example, polar bears not having access to plants, or grazing animals having such abundant grass that they don't eat anything else), natural selection will push it towards the adaptations that make it better at eating that. *T. rex* had omnivorous ancestors, but once you're a *T. rex* you don't really need those adaptations for eating plants.
And part of it is the different body plans required for plants and meat somewhat cancelling each other out. Large herbivores tend to be potbellied, because plants are difficult to digest and require large digestive tracts. Predators tend to need to be swift and sleek. So a predator or an herbivore can specialize more than an omnivore.
As for why you would be one or the other, herbivores have a steady supply of food that can't run away or fight back, while carnivores get easier-to-digest, high-protein meals. | c0e76cb4-1572-4e1e-8050-c72e9635b720 |
cgdc11 | How can they say it will rain at 2:36 PM but also say there is only a 20 percent chance of rain? | With computer modeling they can calculate that the conditions in the forecast area will become ideal for rain a 2:36 and there will be some non-zero amount of rain likely to fall, but that doesn't mean it will rain over the entire forecast area. It is also far more difficult to predict how heavily it will rain once it starts in some given location. Any given location in the forecast area (your driveway, the steps of city hall…) has a 20% chance of being the place that gets the non-zero amount and it may get a little or it may get all the rain that would have fallen elsewhere within the forecast area. | f9341f1f-8cf8-4326-8581-81e195ad1afa |
cgdd0w | Why do twins have different fingerprints? | Fingerprints are not _entirely_ genetic in origin - the develop partially in response to hormone levels and other environmental conditions. Similarly to how identical twins will have different patterns of freckles or moles (due metabolic variations) they will develop different fingerprints. | c1d78c22-c510-49f6-a298-c4858f0ef9a1 |
cgdeoo | What makes magnets attract? | This is one of those things where most physics teachers would probably say, "We prove magnetic properties experimentally, and write them down in a big table for future reference."
Yes, you can say it's because electrons - one of the fundamental building blocks of matter - orient themselves in a certain way within a material, and the itty bitty magnetic charges from each electron either cancel each other out... or they don't, but I don't think that's a real ELI5 answer.
It's like trying to explain why gravity works. There's more to explain than just "the masses attract each other", but you're pretty darn close to the "that's just the way it is" level. | e1a8dabb-8ab4-4b98-8bd9-1fcd6739ddb7 |
cgdjbw | How do animals in the wild know what’s safe to eat? | Some level of smell/taste (bitter for humans, for example, tends to be toxic) is in play, and probably some instinct, however many, say, dogs do occasionally eat very toxic organisms that either kill them or seriously make them ill. How much that happens in the wild is difficult to measure, but there are plenty of cases of pet dogs eating toxic mushrooms/plants. | a635c857-3863-4f6d-842c-de8dfc80c30f |
cgdk02 | What stops battery technology progressing faster? | It is just really difficult to hold large amounts of energy reliably, cheaply and safely (all of which are required for consumer electronics).
Higher capacity batteries exist in labs, but very often they fail on one of those three dimensions:
- They are susceptible to thermal runaway, where they can explode in a non-trival number of cases. All batteries are susceptible to this, but the existing odds are very, very low. An experimental battery that explodes in 0.001% of charge cycles is still too dangerous for consumer electronics
- They aren't reliable. Some high capacity prototypes will wear out after a hundred charge cycles (or less). Your phone battery holds capacity for _thousands_ of charge cycles, so a hundred isn't good enough for consumer electronics.
- They are expensive. Just because we can create a high-capacity, safe and reliable prototype doesn't mean we can scale that to inexpensive manufacturing. If a "perfect" phone battery exists, but costs $5,000 per unit to manufacture, it won't be used. | 278e596d-0da7-4b1a-b9f5-c92cb873e08f |
cgdrvk | How do self cleaning ovens work? | The self cleaning function heats the oven up really hot, usually around 470c. This causes any soil/debris/gunk to decompose into ash. This ash can be easily removed. | d52cf5b8-e0f0-414b-8fea-29b12c50d7b4 |
cgdxsc | What’s the differences between subsidized and unsubsidized loans? | A subsidized loan means the government pays the interest that your loan accumulates while you're still in school. With an unsubsidized loan, you're still on the hook for it. | be30a0eb-8e0d-4b8d-a0de-9bb9190139a1 |
cgeejr | How is car insurance cost calculated? | I believe they look at the odds of paying out for certain characteristics, like age, sex, location, car type and what the average the claims cost the company and then they charge so that they make a profit after claims are paid. | 0d09f278-7280-4f4c-a91f-3a6740a6bb16 |
cgef4m | why does the moon have so many craters and the Earth doesn't? | Two reasons:
First, the earth's atmosphere burns up many small objects that would otherwise impact it. Since the moon has no atmosphere, everything on a path to hit it will impact the surface.
Second, on earth craters will eventually be eroded by wind, water, or tectonic activity. The moon has none of those things, so every single impact crater on the moon will remain there until some other crater is made on top of it. | dd5ea2c8-9fa0-4a17-8322-effb0fedda34 |
cgejsl | What causes those random, short, stabbing pains you feel sometimes? | Compression injury of a nerve can cause these. Like if you're sitting in a certain position that squeezes the surrounding tissue of a nerve over a period of time. The part of you that's getting pinched will swell up later and put pressure back on the nerve. | 49ca00bb-ae3f-4b1a-9563-8cf6fbb1f306 |
cgeoby | How can our eyelids stay open when we die? | Eyelids are controlled by muscles - one set to close them, one set to open them. When your eyes are open, the muscles that hold them open are contracted. When they're closed, the muscles that hold them closed are contracted. Contracting a muscle requires energy, and when you're dead you can't control the exertion of energy (and quickly run out of energy to exert), so you can't alter your muscle contraction state. When you die, then, your muscles tend to either remain in the state they were in, or all try to relax (resulting in a lot of "middle states" (ie half-open eyes) and a lot of floppiness as gravity starts to become the main driving force of posture).
It's actually not true that you close your eyes when unconscious. Nurses often have to tape people's eyes closed after they receive anaesthesia, to prevent the eyes drying out since they don't always close themselves automatically. Eyes often roll back when unconscious (something called Bell's phenomenon) as a refulex which protects the eyes from damage while they're not being used. | bc102202-1c05-4807-a6b4-e27794fac7a2 |
cgetlr | What’s the difference between highside and lowside in electrical functions? | In DC systems, high side is connected to the positive side of the supply, low side to the negative. Typically, the negative side of a single-side supply will be the common ground, which gives high-side and low-side switches distinct advantages. A high-side switch will disconnect the positive supply, leaving the subsystem connected only to ground, a neutral reference potential. On the other hand, a low-side switch will disconnect ground, so a system powered by one supply can be disconnected by one from another (as long as they share grounds), which makes it easier to switch loads that require a higher voltage than the logic can handle. Which is why most RGB LED strips are common-anode. | 6e82ee46-1968-461e-bacf-38926167ad1d |
cgexom | Why is some cheese always cut in squares and some in circles? | This is the answer to a previous ELI5 asking the same question.
When it comes to deli-style cheeses that are made to be sliced and used on sandwiches, the round shape of certain cheeses is strictly a perception/expectation thing.
Provolone is traditionally made in a log shape, from small-ish 10 lb logs up to 80 lbs or more. It's entirely possible to make deli-style provolone in a square block, but it wouldn't sell very well because people expect their provolone to be round.
I'm not entirely sure about the round deli-style gouda. Gouda is normally made in wheel form, and anywhere in size from a couple of pounds up to 25 lbs. It's typically cut in full-height wedges, so if I had to guess I'd say the round shape of the deli gouda is just to differentiate it from the square cheeses.
Deli-style Swiss cheese is modeled after Swiss Emmenthaler, which is made in wheels up to 300 lbs in size. A wedge of cheese from a wheel this size isn't something most people would be willing to buy, so it's usually cut into large rectangular blocks for sale to retailers, who then cut it into smaller rectangular or square blocks for sale to the public. Because there's no real expectation of a particular shape with Swiss cheese, the most economical shape is square. Deli Swiss is made in the same format as mass-produced cheddar.
Cheddar, like most other aged cheeses, used to be made exclusively in wheel format. The round shape promotes even aging, ripening and moisture loss across the entire surface of the cheese. When factory cheesemaking hold in the U.S. in the late 19th century, the wheel format began to be abandoned in favor of large block format, which was easier to make in a mechanized assembly line system, took up less space in storage and shipping, and left almost no waste when dividing into smaller blocks for retail sale. | c98ca460-52e4-48ac-bd1b-9b87fb42cc91 |
cgf0fj | What causes an aurora? | The Sun produces both electromagnetic radiation (visible light, x-rays, infrared, ultraviolet, etc.) and a steady flow of charged particles called solar wind. When solar wind hits the atmosphere it reacts with the ionosphere which is the layer of the atmosphere that is composed of free ions and free electrons. At the equator, the reaction only happens on a smaller scale and isn't visible, and during the day time it would be too faint if there was enough of a reaction. But the Earth's magnetic field pulls the charged particles toward the North and South Pole where the particles can concentrate, and where the atmospheric conditions are best suited for the reaction to occur. The Earth's magnetic field and ionosphere protect the Earth's surface from being bombarded with solar wind. Without them, the solar wind would blast away our atmosphere and burn the land. | a91deb85-7633-425a-9eb4-50351a26bfce |
cgf8po | What is that electric shock that you get when you hit your elbow on a specific spot ? | You have nerves running down your arm. When you hit your elbow just right, that force presses on the nerve causing it to send a bunch of signals to the brain. Normally, the nerve carries sensory information from your arm, so the burst of signals are interpreted in your brain as a wide variety of intense senses, causing the distinctly weird feeling as a result. | c9d4cfa5-3b2d-4a82-924e-2100b1b8336d |
cgfras | Why does insurance not cover some medications? Isn't that what we pay them for? | Imagine you invite your friend to a restaurant and say, "I'll pay for one of your drinks!" Then she comes back with [this monstrosity](_URL_0_). Most people would agree you would be right to refuse to pay for it.
In a similar way, when insurance agrees to pay for medical care, that doesn't mean you can do whatever you want as long as a doctor signs off on it. The insurance company has a right to specify reasonable limits to medical care.
Now obviously this is a big issue in modern politics and a lot of people think insurance is far too limited in what it considers reasonable. But the idea that it's allowed to deny some things isn't really debated. | 311a36cd-70eb-4787-a283-264e1f69e5aa |
cgga13 | what causes/are the bits of skin that I have that just stays white and doesn't tan at all | Probably a genetic skin defect. I have a genetic skin defect which causes white spots about the size of freckles that do not tan. A dermatologist looked at them and determined they were caused by a common genetic defect. | 0e0ae64e-bf98-49e5-8f3a-28a60242f9c3 |
cggea7 | Why do humans flinch to specific noises like certain whistles or anything on a high frequency? | Sudden loud noises can be an indication of something dangerous, high frequency noises can also damage your ears, so people tend to try to protect themselves from that.
People also have wildly different tolerences for pain, so a high frequency noise to one may be an ear-bleeding noise to another. | c4c1c8e6-833a-427f-b6d3-97b8ddf203f9 |
cggitw | What would a 4 dimensional object look like? | Ugh, unfortunately theres no way to effectively explain it like you're 5. YouTube has some pretty good examples but even those are only guesses. | d0a08b9b-fdd1-4a87-8543-090d3149700f |
cggudr | My physics teacher told us that transverse waves travel at right angles. What does that mean | It just means that if (lets use compass points for this) the wave is traveling from South to North, then that direction of travel is perpendicular "_|_" to that direction. In the same way that an ocean wave moves (propagates) in a given direction across the ocean, the rise and fall of the wave itself is vertical.
_URL_0_
See? The longitudinal wave is stretching and compressing in the same direction it's moving in. The substance it moves through "bunches up" and relaxes, creating regions of higher density and others of lower density. All of this goes along the direction of travel. The transverse wave has obvious crests and valleys, and the distortion of the medium it travels through is at right angles with the direction of travel.
It's the difference between creating waves in a slinky by holding it at both ends and whipping one end up and down, versus pushing it forward and pulling it away from you. | 4a4b22d7-a829-40b1-9072-4fd5e79455b6 |
cggvm9 | What causes libido and why does it vary so much between people? | Hormones, particularly estrogen and testosterone but others as well. Everyone has varying levels of them. Females estrogen production increases before ovulation, causing more sexual desire. This happens because the ovulation period best chance of conception (evolutionary trait). In addition there's a psychological factor. Some people feel those urges less than others and are better controlling them. This can be based a lot on your environment as an adolescent and young adult. | 41c6b65d-b9cd-4ec2-853e-c56325b1115f |
cgh30r | If you are you because you got half your DNA from each of your parents, why are older/younger siblings not physical carbon copies of each other? | The half I get from one parent (say my mother), is not equal to the half my siblings got from my mother. Say my mother has {a,b,c,d} I could have gotten {a,b} from her, while my sister got {a,c}, and my brother got {b,d}. similarly for genes from my father, and you get completely different genomes for all of us. | 5e012faa-4b90-4628-b477-a94c39adccee |
cgh5uq | Why does fire always look disconnected from its source? | This is because if the fire is being burnt off of wood, the wood is breaking down into a gas, which then fire will burn off of the gas coming off the wood a few millimeters off the wood. The burning of the wood itself creates embers which is the actual burning of the physical element of the wood. | 138f3f74-171c-4366-a75a-59adf2c51730 |
cghar4 | why has a standard shower controls never caught on? | Because people like different designs. Same reason a standard door handle, blind, window style, or anything else haven't caught on. There's definitely common ones in all of these categories and a few major types but again, whether you want a single control or separate knobs for hot or cold is a cost, installation, and style consideration. | 6f15843a-5c9f-4719-92cc-70e7b2d53b44 |
cghdkk | How is a space rocket's weight supported while on the launch pad? | Any rocket can support it's own weight many times over by design. The reason is that on the pad, only gravity is affecting the rocket, but once launched, the acceleration will typically be 10 to 20 times bigger than gravity.
So if a rocket can handle the launch, than it can handle being on the pad without support. | ee054de2-bddc-4405-9662-0f9eb2d847e2 |
cghj80 | What makes some allergies more severe than others? | In the simplest terms, an allergic reaction is an overreaction to certain chemicals that are basically harmless. Your body's initial defenses are triggered.
The problem is that your cells are *really* dumb. Sure, with all the complex mechanisms that you have and the finely-tuned balancing act between them, you can get a really powerful adaptive defense. But any single component? It's purely a "receive specific stimulus, do single task." So, you have an overreaction, and parts your immune system sets off other part, which set off other parts, and so on. Furthermore, if you set off the *wrong* parts first, you're body's not prepared to counteract itself; you have systems to stop your immune system from killing itself, but if you "glitch" past that with allergies or autoimmune diseases (which is similar to being allergic to yourself), your body won't be able to hold itself back.
Different allergens get into your body in different ways and set off different parts of the immune system, causing different reactions. | 55e57cd6-d0a1-4d3c-b83e-43b98a46da91 |
cghs26 | What happens in our brains when we cry? | I'm fairly sure crying is just a symptom of intense emotion. It's not just tears but your sinuses in general that start overproducing. | e0002ac3-d7bd-401b-864e-56bf29dd0dd9 |
cgi2qj | - Is there any truth to the expression, “Beer before liquor, never been sicker, liquor before beer, you’re in the clear”? | If you drink beer before liquor, you are gradually ramping yourself up to an unknown BAC, therefore when you take shots, they hit you exponentially harder which could lead to getting drunker quicker. However, if you drink liquor first, you will ramp up exponentially from a 0% BAC to a possible tipsy or drunken state, but you can now gently stay at the same level of BAC with beer, therefore not getting sick quickly unless you down a bunch of beer in a short amount of time. | 718aae6f-2d77-4778-8592-46baa0014334 |
cgias7 | When using sign language - is there a way to indicate you are just making a gesture as opposed to signing? Or is it just obvious? | Quick note for those who may not know: there is not one sign language. Most countries have their own sign languages (ASL - American Sign Language; BSL - British Sign Language; Auslan - Australian Sign Language; Chinese Sign Language, etc.). This is because sign languages developed naturally over time, just like spoken sign language, and they are different for all of the reasons that no one uses a universal spoken language.
There are two ways to kind of think of gestures in sign languages. One way is to consider that gestures have their own "meanings" that are not a part of language, and are used by everyone, whether you're hearing or not. For instance, when you point at something, that conveys *something*. Usually it means "look this direction" or "I'm indicating this thing". But it's not grammatical. There's no sentence, there's no formal structure or meaning, and although pretty much everyone knows what you're trying to convey, it can convey a lot of things. So a gesture "in sign language" is still just a gesture, and it conveys whatever meaning it has in the culture that's using it.
Another good example would be the middle finger in America. A lot of people say that the middle finger is a sign, but it isn't (in ASL). It's a gesture. It doesn't "mean" anything in sign other than that you've given someone the middle finger. That gesture certainly has meaning within the culture of America, and you can roughly translate that to "fuck you" or something, but it still doesn't *mean* that. It doesn't *mean* anything except that you're giving someone the middle finger, with all of the connotations attached to that. Incidentally, ASL *does* have signs both for "FUCK YOU" as in "to have sex with", like "[I want to] fuck you" or "[I] fuck[ed a coconut]"; and, "FUCK-YOU" as in, well, yelling "Fuck you!" to someone - which obviously doesn't mean you want to have sex with them, you just want to express that you are upset with them.
Alternatively, if you want to consider random gestures that aren't associated with anything, you can kind of think of them like random noises people make that aren't words. Consider "meh" which isn't a word but still carries some meaning. Or laughing, which isn't a word but still indicates that you are amused. ASL does kind of have a sign for laughing, which is essentially spelling H-A-H-A... rapidly. (It's hard to explain but easy to show, go figure.) But signing "H-A-H-A" is kind of like *saying* "Haha" which isn't the same as laughing.
The point is, users of various sign languages understand the difference between a gesture and a sign in the same way that a hearing person understands the difference between a word and a noise. One is a commonly accepted part of the language, which follows its grammar and is known among users of that language as a word or sign. The other is not a part of the language - although it might convey some meaning in the context of the culture around it, it doesn't follow the grammatical rules of the language, and people don't think it's a word or sign or use it like one. You can even just make up signs, just like you can make up words. If it follows the rules and acts like a sign, someone using a sign language would take it for an unfamiliar sign but it would still otherwise be nonsense. | c5bb8f6e-34aa-4e10-a897-f99211d01a3f |
cgik14 | Clinical depression vs depression vs Major depression disorder what is difference? | Clinical depression and Major Depressive Disorder are different ways to say the same thing. Both are defined by the crieria in the DSM-5. MDD is the formal name whereas clinical depression is the informal name.
Depression just refers to an emotional state. You can be depressed without having a mental illness (like if a loved one dies). Depression turns into an illness when it lasts a long time and/or becomes more intense. | ff18550c-488b-4fed-b2ef-d697ee3d8e9e |
cgikz8 | Why does throat “burn” after drinking water with minty mouth? | You ever see that internet joke that mint is just cold spicy? That's why. Specifically, it activates a protein called TRPM8, which is used by nerve endings to sense cold (similar to how capsaicin activates VR1 to simulate "hot"). Of course, unlike your mouth, your throat doesn't really have a concept of cold -most of your body doesn't-, just agitated and not agitated.
Guess what kind of feeling you get when the nerve endings in your throat give the agitated signal? | a398c7b6-1ba2-43c9-a05e-202e219b3cfc |
cgium9 | Why do pushrod engines have to be so much bigger than a dohc to make similar power, for instance the DOHC Ford 5.0 vs Pushrod 6.2 Chevy vs Pushrod 6.4 Mopar? | The main issue with pushrod engines is that due to the weight of the valvetrain they have issues with floating valves at high engine speeds. Basically the spring is not able to accelerate all the cams and rods fast enough to close the valve in time. So pushrod engines have a lower redline then other technologies like overhead camshaft or pneumatic valves. The lower engine speed have the effect of reducing the effective size of the engine. In order to produce power an engine have to suck inn as much air and fuel mixture as possible into its cylinders. The volume of an engine is how much air and fuel mixture it will suck into the cylinders per revolution. But if you have lower speed you also suck inn less air and fuel mixture even if you have a big volume engine.
& #x200B;
You will find that if you multiply the volume of the engine with the ideal RPM of an engine and its boost pressure you get how much air and fuel mixture it goes through every minute which should roughly correspond to fuel consumption and power production. | 97ec08d3-55fd-452f-bd76-ca45cff872ca |
cgixnf | Why can’t you open a plane door mid flight? | Except that airplane doors open *inward* you have it correct.
The pressure is much much greater inside the plane so the force required to overcome the internal pressure is simply too great. The pressure inside is what keeps the door closed. | 770ca480-586f-4c45-8b5c-342a57b0477b |
cgj0qi | why does crying make your nose run? | when you cry your tears come out of the tear glands and also drain through the tear ducts that empty through your nasal passage. it makes the mucus in your nose more liquid and thus making it run. everything in that region is all connected. | e2ac3bd6-fbe2-49a3-b334-6343a816220e |
cgj1lu | How do shows produced by streaming services like Netflix and Hulu make money? How does viewer count come into play? | Subscription services, be it Netflix or or your mobile phone, or Ball Fondlers monthly all care about the exact same two things:
(1) Getting new customers, and
(2) Keeping the ones you have
Getting new customers you need a reason for them to subscribe. Maybe its a new show, maybe its good service, maybe its something cool, maybe its just great marketing and word of mouth.
Keeping customers you continually need to give them something of value. Maybe they want new content, better speeds, more razors, whatever. You need a reason for people to continue paying you.
"new" shows keep people paying (so they can watch new content) and draws in new customers to watch it too.
Now... this is a bit outside of your question, but the original content shows on Netflix and Hulu aren't made by them. They buy the rights to show the shows from production companies. So thats how the "show" makes money, by selling rights to Hulu/Netflix. Hulu and Netflix make money on subscriptions. | ac77a52e-effa-4d61-b1b3-5015dbb95e1f |
cgjozl | Can you make a brand new internet, like it would be completely empty with no data, no website no anything? | Yes. And you'll have to keep it from connecting to current internet. Otherwise it'll just be part of the current internet.
You'd have to get people to rerun millions of miles of cabling independently of all current connections.
Not very cost effective | 8fe9fcc6-2d3a-400e-81fc-9ef0fbcec4f0 |
cgk7c5 | How does gum have calories if we don’t actually eat it? | Pour a bunch of sugar on a piece of paper. Put the sugar and paper in your mouth and chew it. Once you don't taste any more sugar, spit the paper out. Do you think you just consumed some calories even though you didn't eat any paper? The answer is yes. Same concept applies to gum. | e7144437-37b7-40a9-a27d-77aa9299e021 |
cgke0w | Why do our fingers naturally curl up at rest? | You have muscles to extend them and muscles to retract them into a fist, when not doing either intentionally those muscles meet in the middle. | ca67320a-e817-41f8-97e1-c636c7a0d605 |
cgkj9s | Why doesnt the fire of a light lighter not go back in the lighter? | To ignite, fire needs a mix of oxygen and fuel. The lighter works because the fuel is sprayed and mixed into the air, giving the right combination to keep the flame lit. However, the tube connecting to tank of the lighter to the outlet doesn't have oxygen and thus won't combust. | 581a64fd-3010-49be-a202-4564eb12c473 |
cgl0u9 | When you have a small chunk of skin removed, say you cut your fingertip off, how does the body know how much skin to replace to get it looking like it did before the injury? | Basically every cell in your body has an internal set of instructions to follow. For skin, one of the primary jobs is to either grow or not. So each skin cell is sitting there and constantly going over a checklist of if it's time to divide or not. "Ok, has it been a while since the last time I divided? Yup. Am I big enough? Yup. Is there room for another cell next to me? Nope...dang. Start over." So, if you have a wound your skin cells recognize that there's not skin cells next to them and start dividing to fill the gap. Once they're surrounded by skin cells they stop.
A "fun" fact is that this is pretty much what cancer comes from. Basically something (radiation, chemicals, copy error, dumb luck) damages the "check list". Most of the time when the list is damaged it will be unintelligible and the cell will just sit idle until it dies, but once in awhile the list is damaged in such a way that it most of the conditions that would trigger a stop get ignored. "Ok, has it be awhile since I last divided? Who cares. Am I big enough to divide? Your mom thought I was big enough. Is there room next to me? Fuck it, it's go time!" So the cell divides like crazy making a bunch of cells that divide like crazy.
edit: welp, thanks for all the replies and metals, but now I'm gonna be late for work. Thanks jerks ;) ! Also, a couple of people have said I'm wrong which honestly doesn't surprise me much. Don't, like, make any serious medical decisions based on some rando on reddit in a sub based on explaining things as if to children, k? | 3ec3c295-e404-45b5-9eba-6720bfd45494 |
cgl10d | Many of the Japanese anime are adapted from light novels or manga. Why is there so few Western cartoons adapted from books? | 1. Manga are already cartoons/illustrations. And the USA has had lots of animated superhero shows based on comic book stories & characters.
2. In the USA, animators like Dreamworks and Disney are given a lot of creative freedom to create original work, which takes particular advantage of the animation medium. | 6cc96f09-4b50-4648-9e72-dffca11b1696 |
cgl8yw | How was 16-bit music created on different consoles? | For those of us in the United States, the “Megadrive” is what the rest of the world (except South Korea, where it's the “Super Aladdin Boy”) calls Sega's “Genesis” console.
Carry on. | 99aa39fe-4078-4625-a1ef-805798358ecf |
cglxym | so is it or is it not okay to eat raw eggs? I have heard of people who do this every day but some say it's bad. | Like with most things in life, there is no easy one off answer. Raw eggs can contain diseases such as salmonella, which can be real nasty to whomever consumes it. The CDC says about 1.1 million people in America will get salmonella each year, and about 450 of those will die. Most deaths are attributed to severe dehydration, and those susceptible to fever etc. All in all, it seems like salmonella presents symptoms similar to most food poisoning, diarrhea, vomiting, and just general feeling like shit for a few days. If you're willing to risk that, and are a reasonably healthy person otherwise, you more than likely will not die from salmonella, if you even get the infection.
Now some people may say it is safe and others say that it isn't, and neither of these people are truely wrong. In other countries, Japan as an example, have had raw eggs in their diet for much longer than over here in the west, resulting in much stricter health codes concerning eggs. This better treatment leads to a lower risk of salmonella outbreaks. On the flip side, it is impossible to completely wipe out salmonella, and there will always be some risk in developing the infection. In America, the health codes are considered lax compared to Japan or the EU, and comparatively the infection rate is higher. Infact, the CDC states that out of an estimated 1.2 million cases per year globaly, the vast majority will occur in America because of the laws surrounding the handling of eggs before they arrive to market.
Tl;dr Raw eggs in America are more dangerous than raw eggs from other countries which is why some people disagree. Eating raw eggs can be dangerous if you are already susceptible to infection, otherwise no reason to fear it anymore than you fear food poisoning. | c828eaaa-1cd3-463d-9a5b-cee568fa6355 |
cgmc9z | How does our brain determine the amoumt of pain we feel when we hurt or break a certain part of our body? | It's about the number of nerve cells that are able to send messages to the brain.
If you have a small burn, then that's a small area, which means a small number of nerves.
If you have a small burn, but it is deep, then you get all the area inside and underneath the burn too, and that's more nerves, more messages, and more pain.
But that also means that areas of your body that have higher numbers of nerves, like your finger tip and arm pit, send more pain signals for the same size wound.
It also means that if you broke your foot and also broke your neck, you only feel the pain in the neck. The foot can't communicate with the brain because of the break in the neck, so you don't feel that injury.
It also means that you can interrupt the nerve messages, and if the brain doesn't get the message it doesn't know it is in pain. That's how numbing agents and pain relievers work.
It also means that you can overload your brain with messages, and it can't process all of them. If you have pain in your tooth, and then you stub your toe, it will feel like your tooth hurts less. | 33dff021-54ba-46c8-abcb-933c7d9c32b3 |
cgmf8p | why do you only feel the touch on one finger when you rub two fingers on the same hand together | This is like those optical illusions where you can see two things in the picture, but only one at a time. [Which direction is this train going?](_URL_0_)
When you pinch your fingers together, you *can* feel both of them, but your brain focuses on only one.
You can see this in action, too. If you make the OK sign with your thumb and pointer, it feels like only one finger.
Use your thumb to press up harder; you will feel with the thumb.
Then use your pointer to press down harder; you will feel with the pointer. | b271d610-c65e-4505-9a66-271b2df05976 |
cgmmk9 | Sometimes I get a sudden really loud high pitched ringing in one ear, (can be any one) that fades away quickly. What is it and why does it happen? | sounds are electrical impulses interpreted by your brain, and sometimes the tiny hairs deep inside your ear canal responsible for sending impulses get tripped (from air pressure changes, for example, which your inner ear is particularly sensitive to) resulting in neurological 'feedback.' sometimes this feedback lasts a long time or is permanent, due to a condition that's probably caused by these hairs dying. it's called tinnitus, as other comments have covered. but many people get the occasional ringing in their ear(s).
\*clarity | 1604cd9e-c4e4-43eb-bff3-0f057f466fd7 |
cgmn6r | What happens to the cells of meat when they are cooked? are they still the same or totally different? Like If I take a piece of paper and burn it, does the makeup of paper before it was burned transformed into carbon by the fire? Thanks | Meat is mostly muscle fibers. Heating them up slowly will cause the fibers to contract and firm up. This contraction will also squeeze moisture out. This is why meat that has cooked for a long time tends to be dry and tough. Some cuts of meat also have a lot of fat and connective tissue. These will break down under a low heat, but it takes a while. Cooking meat well can often be a balancing act between breaking down the connective tissue but not drying out the muscle fibers.
This is all independent of the Maillard Reaction, which is what happens when meat (or other things) "browns". Applying very high heat to the surface of the meat causes complex reactions between the sugars and amino acids (proteins) in the meat. I encourage you to look up the details if you're curious. | 0a9cd1e8-1ec4-4446-9277-206a8edd8a14 |
cgmng9 | Why do heatwaves cause massive power outages? | Air conditioning draws a lot of power. The grid stability is challenged, and once one part starts to fail e.g. brownouts, all the loads kicking back on at once when re-connected causes bigger disturbances. This is mitigated by having more capacity within the grid, and the ability to load follow (add electricity as needed on demand.) | 1d04df97-36df-431e-821e-0911a699844c |
cgmt0g | How do Height Increasing Powders work? | Oh, this is an easy question. They don't.
Unless they contain Human Growth Hormone (which is generally available only by prescription), anything that promises to increase your height is a scam. | cf1d2771-91d6-4ca2-bcd4-0eced712fd69 |
cgmycv | When the human eye sees a flat image, say a landscape photograph, and there is an apparent depth of field, does the human eye/brain try to bring into focus the flat image? | Your eyes WANT to see the same image in both eyes. So when you look at a flat photo, because it's NOT actually a 3 dimensional scene, nor is it a composite of two images laid on top of each other taken at different angles (they way your two eyes ACTUALLY perceive the world), both eyes are already seeing the same thing and your brain says "ahh, this is in focus and I can tell that mountain I'm seeing isn't ACTUALLY 3 miles away from me".
This also explains why sometimes your eyes will focus on a patterned surface at the wrong focal point making it look like it's closer or further away than it actually is. (this used to happen to me all the time with a certain trapper keeper cover I owned as a child).
As you naturally look around a room your eyes are constantly changing focus (essentially pivoting more/less cross-eyed depending on how far away the thing you're looking at is). When you turn your gaze to that patterned image, sometimes your eyes aren't quite at the right focal point for the distance the object actually is at, and yet the images are seemingly the same at the center of your field of view, so your eyes lock in that focal point and your brain says "ahh, this object is 3 feet away from me".
But SURPRISE! the object is actually 2 feet 6 inches away from you because your eyes layered the wrong parts of the repeating pattern on top of each other. As you try to grab the object (trapper keeper folder, in my example) your hand reaches in the wrong place, either in front of or behind where it really is, and then your brain notices on the edge of your field of view the border of the folder is not in focus as in one eye the pattern has ended, but in the other eye, there's one more row.
So you close your eyes and shake your head and reopen them allowing your eyes to re-focus on the correct focal point.
Incidentally, this is also how Magic Eye images work, to some degree, you trick your eyes to focus in front of or behind the physical surface of the picture, and the two superimposed printed patterns are in focus behind the physical surface giving the illusion of a 3D object where there actually isn't one.
EDIT: grammar | ef920da8-3519-446c-bda4-af73660803d6 |
cgmzrv | How can the price of food, school, cars, and consumer goods in general outpace inflation? Isn't that the definition of inflation? | Rising prices can't outpace inflation, because they \*are\*, as you say, inflation. They can outpace the purchasing power of a dollar (or whatever monetary unit.) They can outpace income, or specifically the minimum wage, which is often a topic of discussion.
People often use the word 'inflation' to mean 'the whole problem caused by rising prices without a similar rise in income'. But this is, as you point out, not strictly correct usage. | a8b07988-79d7-46c1-9554-26b6b57bd93d |
cgn28m | The U.S. debt ceiling, how it can just be raised willy nilly and how if it's not, what would happen? | The US Debt Ceiling is one of the dumber (which is saying something) aspects of the US Government's Finances.
Basically, the US is the only country in the developed world that places a limitation on how much money its government can borrow. In any other country the government borrows as much as it needs to pay its obligations.
But in the US Congress says that you can take no more than X debt. Which is fine... except that Congress ALSO controls how much is spent. So here's the kicker - Congress will spend Y amount of money which will require borrowing more money than the X allowed by the ceiling AND THEN THEY FREAK OUT ABOUT IT. It's like your mother telling you to buy the school lunch for $5 and then beating you because she only gave you $4 and you spent $5 because she told you to spend $5 or she would beat you for not buying the lunch. It makes no sense and is absurd. | 622d9101-9ea4-471a-b948-775f124576e0 |
cgndwa | What's the difference between sorting by best and sorting by hot? | Hot means they’re very active right now; best means they’re highly upvoted.
Controversial means they’re highly up AND downvoted.
And New means they’ve recently arrived. | 24f44e9d-ace8-401d-82c3-453c234334ff |
cgngqp | How does aloe vera gel help heal sunburns? | There's a compound in the clear gel of the liquid that has been shown to reduce the healing time of burns, as well as open wounds, and has antibacterial, fungal, and viral properties when applied to the area. These are from compounds that help the plant to heal itself after damage, also work on human skin. It has been used for well over 6000 years.
& #x200B;
The yellow part of the plant is also a great laxative.
& #x200B;
No other uses have been researched effectively or thoroughly enough to say its effectiveness. | d1b28ea4-535d-4875-9a7c-2609dc352648 |
cgnjw9 | Why is it when skin is wet, it makes dry skin conditions like eczema worse than if the skin was dry? | Skin conditions like eczema are not the result of dry skin. They are an auto immune disease where your body is literally attacking itself. This can be aggravated by various things. Being too dry, being too wet, getting too much sunlight, being exposed to various chemicals such as chlorine from a pool, etc.
Additionally water on the skin does not help hydrate it. Water on the skin washes away the protective oils that the skin produces, which in turn cause the skin to lose more moisture than it could gain via osmosis in having water on it. This effect is often more extreme in people who have eczema as the disease means they are less efficient at producing said protective oils. | b9b4b726-26f6-4707-a8f0-1fc514d56e13 |
cgnnh6 | what is the difference between white meat and dark meat in a chicken? | Breast is white because the fuel for these muscle fibers comes primarily from a carbohydrate called glycogen and doesn’t require as much oxygen from the blood. Glycogen is useful for short bursts of activity.
Dark meat get their fuel primarily from fat, which provides a more sustainable energy (for the prolonged activity of standing, walking, and running). Dark meat is made dark by two proteins involved in the process of converting the fat into energy for the muscles.
Basically a chicken uses its leg and thigh muscles a lot more than its breast muscles. | f065fd78-bf1f-4ad6-b019-4df6ff1911da |
cgnph7 | Why Nipples are sometimes erect and sometimes not | The nerves in the nipple react to stimuli, both physical and psychological. So an arousing thought, change in temperature, or something as simple as the fabric of your shirt brushing against your skin can cause one or both of your nipples to become erect. | ba5f33cc-f238-434a-8cf3-9b6dcf973a73 |
cgnshz | why is turbulence no big deal for an aircraft the vast majority of the time, even though it feels like a big deal inside of the plane? | Planes are designed with a substantial safety factor, where its wings can hold some multiple of its normal weight. Normally, we experience one gee of acceleration due to gravity, so planes are designed to withstand 5,6,7 gees in order to cope with turbulence and other unexpected phenomena. Not only this, but we as humans don't mind acceleration itself (anything between 0.5 and 1.5 gees feels okay), but sudden changes in acceleration startle and scare us. This is why many car drivers apply the brakes slowly, instead of suddenly; it makes the ride feel smoother even if the peak acceleration is higher. Planes, meanwhile, don't really mind sudden changes in acceleration - it makes no difference to the plane what direction it is being thrown, so long as it isn't being thrown too hard. | 48524c05-b396-4261-bbb5-eac82ab170fc |
cgnt1b | Why does our body temporarily cease managing its own temperature when we enter REM sleep? Why leave it up to the environment? | The way I read it, it is the other way around: it's not that REM sleep turns thermal regulation off, it's that sleeping where we don't have to worry about thermal regulation (or predators) enables REM sleep. REM sleep is the effect, not the cause.
REM sleep only occurs when we sleep in a warm-enough, safe-enough, cozy-enough place. From an evolutionary standpoint, if those conditions aren't met it is in our best interests to not sleep too deep, so we can consciously maintain thermal regulation (tend the fire, arrange the blankets) and keep our fight-or-flight circuitry online. If those conditions \*are\* met and we no longer have to worry about survival issues, we sleep deeper and this new state occurs: REM sleep. We wake up feeling healthier, so we develop an association between sleeping in a warm safe place and feeling rested and energetic the next day. | aba896fc-e1ce-4784-9022-1bf1fd92a87c |
cgo4r9 | Why do toddlers yell when they’re having fun? | It isnt a matter of age. Its a matter of society. As adults we choose/learn that screaming is annoying, especially every time we are having fun. But some still scream whooo at appropriate times like at a party or amusment park. | ebf457ec-a11f-4bc8-83ec-dd3b0a1e4d56 |
cgo65v | - How does creatine work? | Creatine is a compound that turns ADP back to the usable ATP.
ATP is the fuel your body uses to do everything. It’s called ATP for short, or adenosine tri phosphate . Once used turns into ADP, adenosine Di phosphate. So it losses a phosphate ( tri 3, Di 2)
ATP is what your heart uses to pump blood, how muscles move. It involved in nerve signalling and everything else
Your body uses oxygen to make ATP. So your not really burning oxygen, but burning ATP. I hope that shows how important ATP is, and why creatine helps. | 57c9b7da-0d60-4bae-a016-5523accf77e6 |
cgo87u | Brillouin Scattering | Disclaimer: Not an expert, just doing my best to translate the wikipedia article. The refractive index of a material changes when that material is put under different conditions. This includes physical force, electric charge, and magnetic polarity. The result is that phonons (physical vibrations quasiparticles), polarons (electric charge displacement quasiparticles), and magnons (magnetic oscillation quasiparticles) can interact with an oncoming photon by changing the refractive index of the material they're in. Quasiparticles are like... Things that aren't technically particles but often behave like particles.. This interaction can cause the photon to give some of its energy up to the phonon/polaron/magnon that interacted with it, and results in the photon losing some energy (dropping in frequency) and scattering. | 3fdeca5b-ea6d-4b0f-aad1-551572641405 |
cgocyn | Why do spiders make such a special effort to never be seen in the day, but bite me while I'm asleep? Wouldn't they be better off spending all day hunting bugs? | Yeah but every night this giant mountain of meat just stomps through their turf and then splays out asking to be eaten for 8 hours! | 77190604-a169-4b43-afaf-c90101f14ae5 |
cgogem | why when you scratch a bug bite it becomes more itchy. | Your body releases a chemical wr.call histamines when it takes damage, like a scratch or a bug bite. Histamines cause inflammation (swelling) and redness, as well as itchiness.
So when you get a bug bite, it itches, and scratching it is seen as damage by your body, causing it to release more histamines. | 553855e3-941f-47e3-8ee5-45262fcf21e1 |
cgogn6 | How can enlisted soldiers in the US get a degree while on active duty? For example, the U.S. Navy? | The GI bill, part of the agreement they get for enlisting, pays for college tuition (or most of it) and many colleges offer online courses in modernity that you can take via the internet. This allows soldiers to take one or two classes at a time during their free time. | 29e13a8b-2b59-48f5-93d7-bb337d8caf5d |
cgop0a | How do panic attacks manifest from seemingly nothing at all? | Not sure this is really BIO so much as PSYCH, and the answer I have is more anecdotal than scientific, but hear me out: Often times, when things scare us, we think about them. This is rather reasonable, since thinking about problems usually helps us fix em. However, sometimes thinking about them makes them more scary. Of course, this happens all sorts of times, and it doesn't usually result in a panic attack. Panic sets in when our minds don't know how to respond to a situation, and I would describe it as the "drop your bag and run" response. When we panic, we stop processing. This all means that we keep picturing the problem in our heads, but we can't actually do much *thinking*. We just have this mental image of the problem, and we can't do anything to get rid of it because we aren't really thinking. This often combines with things like hyperventilating and sobbing, which left unchecked usually lead to chemical imbalances in our blood (too much co2, for instance), which drives our brains into super-ultra-panic mode, since suddenly our brains are being subjected to something they shouldn't be (acidic blood from too much co2). All of this happens in the span of a minute or so, and boom. | 31659c59-a8e3-4923-8b56-85f43276fd42 |
cgoroi | My parents hate each other, but are staying married for us kids. Is there a peer-reviewed study that can help them decide the best course of action? | I don't have any peer reviewed journals but I do have the horrible firsthand experience of growing up with parents who hated each other but remained together: they need to split up asap. If they hate each other and are fighting every day it's only unnecessary stress on themselves and their children. It teaches kids to sacrifice their health and happiness for the sake of others and a whole heap of unhealthy arguing techniques and anger. There's nothing worse than knowing your parents are unhappy because of you, even if they think they're staying together "for the sake of the family." It just makes kids feel guilty and it's unfair on them too. Ask anyone who had parents remain in a loveless relationship, they'll tell you the same I did | 989550e5-a8d3-4219-bf41-f339bb39736a |
cgorsv | If you own a small business and have paid your employees, taxes, and other costs. Are the money left (profits?) considered your income? And do you pay tax on that? Or do you assign yourself a salary and what is left belongs to the business and does it get taxed? | Depends on if your business is a sole proprietorship, single member LLC, multi member LLC, an LLC with the “S” tax election, an S Corporation, or a C Corporation.
Sole Proprietorship: All profits and losses pass to you individually. You’re also personally liable for anything that goes wrong. Pro Tip: form an LLC or go get a free consultation with a business attorney.
Single Member LLC: Profits and losses pass through to you personally, but your liability is limited to the Company’s assets. You also have to pay self employment tax.
Multi-Member LLC: Profits and losses are split in proportion to each members ownership interest in the company. You also pay self employment tax.
LLC with “S” election: You pay yourself a reasonable salary, and that salary is not subject to the self employment tax. Remaining profits and losses are passed through to you and any other shareholders in proportion to each shareholders percentage interest in the corporation. Whether or not you get taxed on any distributions depends on your basis, but this is where is gets complicated and I can’t ELI5 (just let the CPA worry about this)
S Corporation: see above
C Corporation: The corporations profits are taxed at the corporate tax level and then any dividends made to shareholders are taxed as well. This is called double taxation and it’s why C Corporations are not ideal for small business owners.
Unethical Life Pro Tip: Want to live a lavish lifestyle, completely tax free, and without much hard work!? Start a non-profit seed faith mega church, go on TV, and convince all the sheeple to send your church money, because god will take the little “seed of faith” they send and will “sow” the seed into 10x the amount they sent. | a37e89ad-2a02-4423-9402-2c15c60a9ddf |
cgp7rq | How are we able to see planets through the naked eye like we see stars? They don't shine or glow, so are we just seeing a reflection? | Yup. Reflections from the sun
They're much closer than stars (except our own sun of course) | a4e1aae1-093b-45f4-8191-420b34434175 |
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