query_id
stringlengths 3
6
| question
stringlengths 1
299
| goldenAnswer
stringlengths 3
35k
| doc_id
stringlengths 36
36
|
|---|---|---|---|
1n6zbx | Why airline tickets in the US are so damn expensive? | That's funny. Here in Canada we think of the US as a cheap country for flying. One member of parliament once pointed out that it was cheaper sometimes for him to fly from his home in BC to Singapore than to fly to his workplace in Ottawa. | 47d1f548-cdad-4277-b9ab-20e77a1096f1 |
1rwfv8 | How do I determine order of atoms | I believe we put the less electronegative agents first, followed by the more electronegative ones.
Electronegativity is an atom's tendency (or a functional group's tendency) to attract electrons. So for single atoms, the farther to the right they are, and the higher up, the more electronegative (ignoring the noble gases). Oxygen and fluorine are the most electronegative, while atoms like carbon, with four valence electrons, aren't especially eager to give or take electrons. | 0a0dabd4-e7ae-4acf-be15-6a3234efba12 |
1qzlsp | What is existentialism? | In a few words, the belief that everything is inherently meaningless, and any semblance of significance is entirely subjective and derived by the individual experiencing it.
Example: We're alone in the universe (which will some day fold in on itself and invalidate the entirety of human achievement), we're going to die someday (before immortality is discovered, and even the greatest among us will be little more than a name mostly uttered out of context) and none of us can ever truly be sure someone feels the way we do or loves us like we love them.
But right now, I'm watching my cat do stupid shit and it's making me laugh, so I've got that going for me, which is nice...
**TL;DR:** Life is entirely what you make it.
**EDIT:** Realized I may have lost my initial point in my meandering prose. What I was getting at is, despite all evidence that life may have no actual meaning, existentialism dictates you can find that meaning anywhere, simply by appreciating the experiences existence has to offer (hence, the name).
So, life is basically meaningless. But thanks to my cat's silly antics, I had to pause, reflect, shamelessly lift a Kurt Vonnegut quote and think "If this isn't nice, I don't know what is." And in finding joy in a mundane moment, I've manufactured my own meaning from out of the darkness. | 2a81ecee-7f0d-4257-aeba-44fb767fd5f6 |
1g6na5 | If I was driving at 100km/h and crashed into a car in front that was going 90km/h, would the impact be equal to crashing into something stationary at 10km/h? | Yes, the initial impact would be like 10km/h.
However, if the initial impact causes loss of control (which it might, depending on the exact nature of the impact), the following impact with the scenery will *not* be like 10km/h! | eab637da-f826-4a13-9130-b663c4ce2d71 |
308slq | Why are there different research funding organizations for different types of cancer? | We know the root cause of cancer, cells that multiply uncontrollably due to some sort of mutation or defect. Each type of cancer requires different methods to treat however due to the nature of the type of cell infected. | 8fe615ee-b472-453b-8d7d-cb659fa69089 |
660zif | Considering all the different elements of sound, how is audio translated into binary so that a computer can understand what it's processing? | As complex as sound.. uh.. *sounds*, really your ear drum is interpreting all those various sounds into one wave form. That is because you have one ear drum in each year, and it has only so many dimensions. It's really a matter of how much pressure, and how fast, the ear drum is vibrating.
When we first started studying sound, we literally just looked at how our ear drums vibrated, and replicated that with analogue technology. It's just a wave, up and down.
So with computers, the binary is just representing that *single* wave. There are a LOT of ways of describing this in binary, depending on how much *fidelity* you want to the actual wave form. Basically, the binary representation will describe in a certain time interval where the wave goes. It goes up, it goes down, it stays flat.
So basically / - \
That's just three little symbols that can represent all of sound. | b0b34276-bc5c-46f5-a101-58ad00cdaaaa |
823ib6 | Why is fish (or sea food) so much softer than mammal meat? | Basically fish have less collagen that attaches muscle to bone because fish don't need the skeleton to support them because they swim in the water every day. Also their muscle fibers are shorter that's why when you eat fully cooked fish you notice the pieces fall apart in consistent chunks. | 23274ac9-137f-4b1b-9808-34afe55a76fb |
2nj7h1 | Why does my skin feel so sensitive and why do my muscles ache when I have a cold? | One of the main reasons that your body aches when you are sick, like with a cold is that your body's immmune system is producing plenty of anti-bodies.
These anti-bodies also produce histamines which typically dilates (widens) blood vessel near an infection, this allows for more of the body's defences to get at the infection. There are histamine receptors in blood vessels that cause them to dilate. As these chemicals are released into your blood stream they can end up in your muscles or other body parts. Various body systems can have receptors to histamine that can then trigger a pain receptor.
In addition to histamines there are biochemicals called cytokines that are released when the body has an immune response that are also known to trigger a biochemical pathway that can affect pain receptors.
TL;DR The body's immune system sometimes trigger pain receptors or make them more sensitive when they release histamines. | 168abd67-cfe7-4be1-a3b4-797257d0f2ae |
2pxo4u | If cracking your knuckles is pockets of air escaping, how does the air get in and where does it go? | It doesn't go anywhere. When you crack your knuckles you stretch out the sacks of fluid that act as cushions but they don't break. Stretching them creates a vacuum inside which pulls any dissolved gasses out. That's the cracking sound, the bubbles just stay inside that sack and eventually dissolve back into the fluid. | 4b418135-3aec-488f-9f54-f41ec427f3c8 |
r0z2g | Why is blackmail illegal? | its coercion or extortion involving a threat of harm or slander.
youre basically demanding money under threat of harm. | e5a93617-44f5-40a3-a26d-1a38f8ae67bb |
7jt6ds | How is disney not a monopoly? | To be a monopoly, you have to control all (or nearly all) of the commerce in your given market. Microsoft was thought to be a monopoly in the past because they controlled ~95% of the PC OS market.
Disney is in the entertainment market. Even after the merger, they won't even control 50% of that market, much less the > 75% you really need to have a serious discussion about a company being a monopoly. | d8c1955d-d6a3-4fd3-934c-59836617ce34 |
24chce | Why do flies and gnats consistently bother the same person even after being shooed away? | They're attracted to the smell, or the color, or maybe they're just jerks. | 807bc5b6-2552-46ec-b138-6e4fceb7b95a |
2vqq7d | Who creates the, I assume mostly not real, computer programs we see characters using in films and are they actually functional? | I would guess it's just added post production via a cgi program. No reason to write a fake program when all you need is something to just look like a program sense nobody has to use it outside of a scripted scene | 3e613dd7-669a-4627-a579-2bbf11dd8658 |
5yo7wk | If our skin cells are constantly dying and being replaced how do tattoos remain on our skin forever? | > If our skin cells are constantly dying and being replaced how do tattoos remain on our skin forever?
The ink is injected *below* the skin that is constantly being sloughed off. | 27b1074f-709c-4f5d-bfd8-6ced99b4ace2 |
2p6r3t | What does it mean it mean to be "in shape" physically, and what does my body actually do if I'm in shape? | "In shape" is just another way of saying that you exercise with some regularity and your diet is good; you're not obese.
Being too much or too less of anything is detrimental to your health, and being in shape is that balance for someone where they are not obese and scoffing down processed foods 24/7, and it provides your body with loads of good stuff like increased lung capacity, low blood pressure, etc all of the stuff they tell you why you need to exercise.
Being "in shape" has no universal standard. For example, I rarely go to the gym, and my primary form of exercise comes from jogging every morning and simply being on my feet for hours every day. (NYC life FTW). My diet is mainly light foods like fruits/vegetables though I eat a bit of steaks/protein a lot as well. So for me, I consider myself "in shape" because I'm not "fat", I can run a few miles easily, and I eat right for the most part.
Someone else might require something different altogether though. | ffa05742-31b0-48ca-80b5-80b7c5a38514 |
3mij1r | Do alcohol, tobacco, caffeine fit in 'receptors'? | Yes and no, it depends on the drug. Some are structural analogs to neurotransmitters (like nicotine) and some act on neurons and stimulate/inhibit release of neurotransmitters or their binding to receptors (like alcohol)
For example, nicotine (the active ingredient of tobacco) is a structural analog (similar chemical structure) of the neurotransmitter acetylcholine and binds nicotinic acetylcholine receptors (you can see where the name of the receptor came from) in the central nervous system.
Alcohol, on the other hand, binds to GABA receptors in the central nervous system and increases its binding strength to the neurotransmitter GABA. So while it's not a structural analog, it does increase GABA activity.
Caffeine is a receptor blocker for the adenosine receptor in the central nervous system. Adenosine makes you sleepy, so caffeine blocks this and delays the sleepiness. However, keep in mind that adenosine is still accumulating, so once the caffeine is metabolized, the adenosine kicks in and you get sleepy again.
Every drug works slightly differently, so if you want to know more, I recommend taking a pharmacology class. | 0bf7c82f-b2c7-440a-bf3d-47442d2165c7 |
5x5ktc | Crowd gps | Crowd GPS apps are different in that they give your more real-time information such as obstructions in the road, red cam lights. All the added real-time information is gathered through different people who use that app. Functioning as a self sustaining community, people update the public map with new information wherever they are. Others can vote on whether this info is accurate or not in. The more people that apply to that "community" the more accurate and timely that info is. | 3f6bc3c9-04ef-4371-b0e2-64a7877d76b9 |
6u9sh0 | Would we have to brush our teeth if we consumed no sugar? | Yes, you would want to remove acids as well, as they also cause tooth problems. Brushing your teeth can also help remove pieces of food stuck in your teeth, which would otherwise rot. This is an area where flossing is helpful as well, which you should also do everyday. | 6a32f5bb-9f82-42db-bff1-a142d0428c12 |
309cis | Why do people say "What is -----" on jeopardy | The guy who invented jeopardy was on the daily show once, and he explained it as follows.
He said that jeopardy was one of the first attempts to have a real quiz show after the big quiz show scandals earlier in the 20th century. Those involved shows were the producers would give one of the contestants the answers in advance, to guarantee "interesting" winners.
When he was trying to pitch jeopardy, TV executives were still wary of these kinds of scandals---not that they thought jeopardy would involve cheating, but that people wouldn't watch trivia because they'd assume it was rigged---and so he came up with the idea of "answering in the form of a question." It allowed them to do gimmicky ads saying that you didn't have to worry about cheating because *everyone* got the answer already (in the clue on the board), and they weren't looking for answers, they were looking for questions. | 83fdb63b-1824-4c51-a377-40b751a60c75 |
4vtb5q | Why do some people (like me) get really squirmish about things like Veins, the inner mechanics of Reproductive organs or blood and injections, etc ? | It sounds like you might be experiencing a vasovagal syncope, which is the mechanism that causes people to faint at the sight of blood. You get this because you are a wimp.
No, actually this happens because of a nervous system malfunction. Rather than activating the sympathetic nervous system which would be the "fight-or-flight" response, it activates the parasympathetic nervous system which is the "rest-and-digest" response. Rather than getting amped up for a hand to hand fight to the death you are more likely to poo your pants and cry. And weirdly, get an erection.
Shitting oneself isn't a terrible evolutionary response to danger per se; deer do it all the time, as apparently do opossum (the "play dead" thing is only part of it, as if you catch them in a cage be prepared for grassy diarrhea all over). Of course this probably isn't very comforting but that is probably why it happens to you. | ea87af9f-7934-4dd7-971e-5cdcb7d869e3 |
5654fo | Why did the english language rename other countries? Ex german=duetsch | Countries didn't always have the same borders as they do today and so some names come from the names of the people who lived there way back when and have become corrupted in different ways over time. Example: the Franca people led to the name France and Francaise. Different rules in different languages can explain how the descriptor for the people can be different (French/Français).
Germany particularly formed comparatively recently and was a lot more of a mish-mash of tribes than other countries. There were Germanic tribes (hence Germany in English, from the Latin), Teutonic tribes (hence Teutonic also being a descriptor for being German), the Allemains (hence Germany being called Allemagne in France) and so on.
Back in a sec when I've Googled something...
Edit: Just wanted to check a spelling before I typed it. Some people living in that area just called themselves the *Diutisc*. Not a specific tribe but just means something like 'the people' and they used it to describe themselves as compared to others in the same way the Romans just used 'barbarian' for any scruffy foreigner. So that'd where Deutschland comes from, and obviously the word Dutch to describe something from Holland/Netherlands. | bfaf1031-058a-4af0-a02c-aada6f3ed733 |
3fq6nb | Why when you breathe out with an open mouth is the air warm, but if you purse your lips then the air is cold? | Its not cooler air, it just mixes with the surrounding air faster. Add that to the fact you are probably blowing onto your sweaty fingers or palm, the evaporation of the sweat makes you feel like its cooler. | b01f8552-2b36-4b62-a7fc-c9734a933715 |
1bru8j | The rise, fall, and importance of the Byzantine Empire. | Since the Roman empire had lots of trouble - civil wars, plagues, barbarian invasions - it was divided into two parts, because it would have been impossible to administrate otherwise.
After the western part collapsed and Rome was looted by barbarians, only the east part remained. Since the only remainder of Rome now had mostly Greeks living in it, they switched their language to Greek and Capital to Constantinople. They still called themselves Romans, but since the new empire was pretty different from the old modern historians named it the Byzantine empire instead for convenience.
For a while, the Byzantine empire did really well, and thanks to an [awesome general](_URL_0_) managed to retake Italy and Africa from the barbarians. The success wasn't long-lived though, and due to plagues, civil wars and shitty emperors they lost a lot of territory to the Seljuk Turks.
Then came the [fourth crusade](_URL_1_), which got itself indebted to Venice because they couldn't pay for the boats made for them (seriosuly). So instead of going to Jerusalem, they had to become mercenaries for Venice instead, sailing to Constantinople and sacking the city. The Byzantines never really recovered from it, and the Turks proceeded to siege and capture Constantinople in 1453, which finally ended the empire. (unless you count the pope crowning Charlemagne roman emperor in y. 800, which would mean the roman empire 'officially' fell in 1835, when Napoleon forced [this guy](_URL_2_) to abdicate.) | a440716b-879a-4858-8a8f-ab08c2fb84e9 |
1l1ie0 | why toasted bread tastes different than regular bread | No. When you heat bread, chemical reactions take place on the surface of the bread that fundamentally change it. See the recent question about the Maillard reaction for a little more, if you want. | d2c3ea2c-45f1-4eb3-8bbb-a397cf8f3101 |
3e3x6l | Why is it that I see so many surfing videos that show surfers sitting out in the water with no waves? | Often we wait behind the waves to prepare, find a good wave or take a break. Then you move up and "drop into" the wave. Waves may come in sets of three for example and you want to ride the best one so you wait. Sometimes you wait a bit. | 4196fffa-cde1-443d-aae2-083ae0cba352 |
65y2fs | Why is steam formed in a shower at 50 degrees Celsius? | Most people refer to visible water vapor as "steam," but technically it's not steam. Steam, by definition, is the gaseous state of water (over 100 degrees Celsius at normal atmospheric pressues). When steam is released into air which is at normal temperatures, some of it condenses into the clouds which we CALL "steam" but that is still condensed water vapor, and not really steam. What you're seeing in the shower is just very fine water droplets condensing in the air. | d56f815c-e16c-49f1-9928-bdaec5d4dd29 |
2nwypq | Why are oil prices plummeting? What is OPEC and why are they not cutting production? | There are a lot of reasons why oil prices have dropped recently. One major one is a recession in places like China, and a surplus of extracted oil. OPEC is the organization of petroleum exporting countries. OPEC is group of a bunch of countries that work together to coordinate oil production. Why opec isn't simply cutting production as they've done in the past is because a) that wouldn't really help these countries at this point
b) another cause of the drop in oil is increase in production in the us and specifically by fracking which is cheaper than conventional methods of drilling, because of this increased use of American oil, opec cutting production would not effect this oil. | 4c9af2b3-1fce-4445-baf8-9e3364498e81 |
jwp5w | How is glass made? | When sand is melted you get a hot liquid substance, then you can form it into shapes with special tools and when it cools you are left with glass. | ded9c389-ec48-4ea8-a449-7b27cb466d63 |
5krjz0 | How exactly does my neighbors property effect my property value? | property value is just a guess at what an average consumer will be willing to pay. If you have a nice house, but it's surrounded by meth labs, no one will want to pay very much to buy it. | 456fa8b5-797b-4b81-a85a-5117939a075c |
5267u6 | Why is it that so many people remember how blue the sky was on 9/11? | The contrast was striking - over and over again, all day long, I remember people remarking on it - this massive and horrible event, on such an especially beautiful day.
And certainly in NYC, most of us didn't go to or stay at work all day, either, so that may also contribute to our noting and remembering what a "nice" day it was outside. | c8ffaf86-55b8-4b54-a8eb-f0c71d40c3e4 |
1esm7t | Why isn't "quantitative easing" money just given directly to taxpayers? | The Fed isn't there for the sake of taxpayers. It's there for the sake of banks and that kind of guy. | 5ef6c6d0-982f-4549-92c5-d6eff6fec92d |
tnn80 | Why are unhealthy foods seemingly always less expensive than healthier alternatives? | Less than 1% of federal subsidies go towards fruits and vegetable. With 63% going to meat and dairy and 20% to grains, which is mostly used to feed livestock. Hence, the true market price of unhealthy food are artificially suppressed by federal subsidies.
source: [_URL_0_](_URL_0_) | fa5d1237-e1b8-4698-99fd-48e79fa9cbdf |
mdmqm | Shakespeare's genius | Nobody popularized memes like Shakespeare, ever, in history. Think of all the little words and phrases you have made up... does anyone else use them? Does everyone one else use them? [HERE IS A PARTIAL LIST](_URL_0_) of words and phrases that have no record of appearing before Shakespeare used them. And they left out "eyeball". Yep, Shakespeare has the first known use of the word "eyeball" | d641b993-9435-4254-ae58-150db9fb775c |
40ns5h | How the IRS would tax the winner of the power ball for the foreseeable future | If you took it as a lump-sum prize they would tax you 350-400 mil as you say, but after that you wouldn't be taxed on it as income anymore because its already been taxed. It is not "income" just because you still have it next year, the only way it would continue to be taxed is if you invested it you would be taxed on capital gains (so technically it isn't even the prize money being taxed, just the money you GAIN) | 8bf80695-9ade-4fd4-a0ff-f03e9a12a505 |
41fv0s | How does the mouth deal with things hot enough to burn most other parts of the body? | If it's hot enough to burn other parts of the body, it'll burn your mouth, too. In fact it'll probably burn your mouth easier than other parts of the body. | 3f8bf88d-5ecb-419c-bde2-cc2276366ff8 |
36pdl1 | Why is bathroom water so much better than kitchen water? | Clearly because you are a dog.
Really tho..."Most people like to drink water that is very cold. In the bathroom, the water is often very cold because the person getting a drink first uses the water closet (toilet) and flushes. This starts the flow of cold water. Then they wash their hands, which continues to flow the cold water. By the time they take a drink, the water is nice and cold. This fools the brain into thinking it tastes better."
Kitchen water on the other hand is often left sitting in you pipes for long periods of time. Which is often why people open the tap and let it run for a few minutes before getting water. The colder the water the better the brain thinks it tastes. | 4c6bb424-5a97-49b8-9179-1630e58d4cf9 |
233njw | Why is allergy medicine so expensive? | A lot of the newer allergy drugs have a narrower focus than previous generations of allergy drugs. Benadryl is an antihistamine, but it affects the whole body system much more than more modern drugs. Drugs like Afrin can clear congestion, but at the expense of elevated blood pressure and tolerance buildup. Its effects go beyond relieving the targeted symptom. The newer medicines take a lot of research to find the specific molecules that will fit into the specific receptors in order to block an allergen from filling the receptor and causing an immune response. The newer medicines try to have a targeted approach for the symptom they are taken to alleviate. A lot of allergy treatment medicines are forms of steroids. The amount is small, but it can help the body lessen its reaction to allergens like dust and pollen. If one takes stronger steroids, it ends up causing damage. That is why many of the drugs do not go over-the counter, because there are risks that need medical monitoring, above and beyond the common drugs found on store shelves. Many allergy medicines today are truly better than the ones of 20 years ago. | 52714475-e4f4-416a-ade6-bb042c7d24c7 |
6wz5nz | It seems that when devastating disasters happen in North America, less than a hundred are killed, but how come in countries in the Middle East, Asia and the Far East suffer far more casualties for similar disasters? | that's easy, it comes down to primarily two things:
- Money
- the number of people living there (population density)
While the US are huge, they're not as densely populated as other areas, especially in Asia or the Middle East. In Texas you got an average of 40 people per square kilometer (or roughly 100 per square mile). The worlds average is about 60 (thats including the deserts, greenland, etc). Pakistan for example has a density of about 250 people per square kilometer.
And then, more money means better houses, better infrastructure, better governments with better (and better enforced) safety regulations when it comes to building/maintaining stuff. It means having the option to leave an endangered area and go somewhere else, etc. | aefd3014-b71e-41fe-a3f8-c206d0983af8 |
4hjmlu | Why is -3 not an applicable square root of 9? | The square root of 9 is ±3.
The principal square root of 9 is 3.
Usually you use the things that make sense. I don't understand your problem, but usually when solving problems like
x^2 = 9
you write that
|x| = 3
x = -3,3.
This problem has 2 roots. Both of them satisfy the equation x^2 = 9. | aa5fa377-7160-4f24-86d9-2cdd2d9d2e44 |
2djbs9 | Why is water transport so inefficient? Why can a mid-level car easily reach 200+kph, while you need a 1000+hp offshore boat to reach the same speed? | Essentially friction and surface area. I'm no expert but look how much of a boat/ship is actually making contact with the water, now look at how much surface area your tires on your car take up, a hell of a lot less.
I'm not a smart man but there's my two cents. I'm sure someone will explain it better. | aa7c8a06-3ab5-45ea-ac1c-a489942ef53a |
2gx2cw | Why is longitude measured in non-parallel lines coming from the poles instead of in parallel circles emanating from the Prime Meridian and IDL? | One of these ways is really easy and convenient for plotting a map and navigating. The other is really, really, really annoying. If you plotted the parallel circles on a flat map, you would get two sets of either concentric ellipses or circles depending on the projection you use, and you couldn't keep your East/West coordinates fixed if you traveled due North/South. | 2a8adc22-7199-42ef-92de-59b8044ed093 |
79ne51 | Why does food turn black when it burns? | Burning could also be called carbonising. I'm sure there's someone who can explain better than me, but burning food is the exact same as burning a lump of wood. Burning is a chemical reaction called combustion, and I can't remember any exact formulas but it uses oxygen, along with the organic compounds in the wood or food (generally composed of carbon, hydrogen and oxygen with some other fun things in there). One of the by products of the reaction is carbon dioxide which is just released into the air, and another is solid carbon, which is the black stuff left behind. Sorry if this answer is a bit long but basically;
TLDR: it goes black because the combustion reaction uses up most of the other parts of the compounds in the food, and what's left is solid carbon which is black.
Edit: as a few people have pointed out, it is incomplete combustion that produces solid carbon, which is the result of imperfect combustion conditions, for example not enough oxygen available for the reaction. | 5d61648f-c914-48a3-8862-1a7b6368f173 |
3aylcl | Why are beef hotdogs not brown? | Hotdogs contain sodium nitrate as part of their curing process. Nitrates make meat pink. In fact besides hot dogs they are the reason why corned beef is the color it is, and are commonly found in things like bacon, sausages, and other 'cured' meats. | e9fd898d-82ed-4e89-a8a6-754bb2cd4ccb |
47w4or | Slow charge vs fast charge overnight | It doesn't matter. It automatically regulates power supply to prevent anything from damaging the battery; for instance, when the phone reaches 100% it stops charging, and only starts charging when it falls below like 98%-95%. | 4cdb78ae-17c2-4495-813d-e12a7eefdb1f |
27ga9h | How Long Will The Worlds Population Continue To Increase? | **TL;DR - about 30 years.**
Populations in most of Asia are stagnating. India is leveling out. Japan and most of Europe have *declining* populations. The US is leveling out. The only place left on Earth to experience a population boom is Africa.
Scientists have predicted that Earth's population will plateau at about 9.5 bil. Earth is capable of supporting that many. It will be a little tight, but we'll be fine. | 0e597fb1-1684-4ce6-8254-de46d2562567 |
2mw7q4 | How can flight with a layover in Prague, be cheaper than booking a direct flight to Prague? | Airline prices are generally based solely off the origin and destination, and not anywhere in between.
Pricing is a function of demand and competition. If there is high demand and little competition on flights from your city to Prague, prices will be high. If there is low demand and lots of competition from your city to Moscow, prices will be low, even if you have to stop in Prague.
It's called [hidden city ticketing](_URL_0_), and if you read the fine print when you book a flight, it's not allowed. For example, if you book a flight from London-Prague-Moscow because it's cheaper than London-Prague (where you really want to go), you're not allowed to leave the airport and stay in Prague. Well, you can, if you only have carry on bags, because your checked luggage is going to Moscow. And once you miss the Prague-Moscow flight, the rest of the itinerary is canceled so hope you didn't plan on getting back to London. If you're flying one way and aren't checking luggage, you can get away with it, with one huge caveat: If you book London-Prague-Moscow, the airline's obligation is to get you from London to Moscow. They're well within their rights to reroute you through another city if there's bad weather in Prague or the London-Prague plane has a mechanical issue. For example, they might change it to London-Munich-Moscow, but you wanted to go to Prague. Oops. You're SOL. | c8e72a38-d61e-45a0-a01f-60e28a6132a3 |
5ssqni | Why does protesting work? You see massive nationwide protests when there is civil unrest, but why can't the government just ignore it until the protestors give up? | Protesting isn't about getting the government or entity you are protesting to change because of the protesters. They will always be dismissed as a minority opinion and troublemakers. It is about getting a larger group of constituents (the ones who would never actually go to the protest) interested with the issue. It is about attention and media coverage and creating a groundswell. You hope by having 100 people show up you get 5000 to write their congressman. You hope by staying in place for a month that you get 50,000 to care. In short you hope to influence a larger group, create pressure. | b6b7ef1d-4bbc-40f0-91d0-52c19075adfc |
2416aq | Why can't computer screens alter images for visually impaired people (glasses) to be clear? | Think about it this way. A normal person's eyes are like a funnel. Anything that gets poured into the funnel comes out in a tight stream. Someone with very bad eyesight has eyes like a colander. Even if you pour the exact same thing into the colander, you end up with a mess of random crap coming out the bottom.
Glasses work by basically putting a funnel inside the colander so everything comes out one hole in the center. It redirects everything into that hole.
Could you pour things into a colander in such a way that it would come out as a stream, i.e. straight down one of the holes? Theoretically, but it would be very difficult and it would have to be adjusted depending on the type of colander, its size, its location, etc. If you move it even half an inch, the stream you're pouring into it hits the metal near the hole.
So essentially the only way to make this work would be to fine tune the image *extremely* specifically, at which point it would only work for one person in one location. You'd have to have your head bolted to your chair to prevent tiny head movements from ruining it. | 83026819-a1ab-4c8e-861d-130718ac6068 |
3ozhhk | What happens to the pieces of a sliver that break off and can't be removed and therefore stay under my skin? | Usually they work to the surface over time as new layers of skin grow from beneath. The human body is pretty amazing at ridding itself of foreign bodies. | 9110e2dd-c462-4ef2-b373-69acaaf6cb8a |
1nv4a5 | Why are cats (and other animals) noses wet? | Because they often lick their noses. Think about how it smells when it rains. It's a pretty strong, distinct smell, isn't it? It isn't the smell of the rain that's sticking out - it's everything else. Moisture makes it easier to smell things we normally would have missed.
With dogs and cats, it's the same exact thing (I believe). They keep their noses moist because a wet nose fine-tunes their ability to smell. | 902803ee-6def-4de7-9f55-6827c6c9b380 |
tzc7g | Asthma | Some illnesses make you sick for a long time, like cancers and HIV. Some illnesses make you sick for a short time and then they go away, like a cold or a tummy bug.
Asthma is an in between illness. You have it all the time, but it only makes you sick some of the time, as others have explained. It's like an nut allergy, you're always allergic, but you're only sick if you eat nuts.
At the moment, we can give asthma sufferers treatment if they are sick, but we can't cure the whole illness. The sometimes aspect of asthma (and allergies and other "in between" illnesses) makes it harder to come up with a reasonable cure because all medicines have side effects. If the illness is only making you sick some of the time, most people would not want to have the side effects all of the time. Plus, sometimes the side effects are worse than the illness you're trying to treat.
Also, we can cure (treat until it goes away) something like an infection because that's caused by something outside the body. When all the bacteria are gone, the sickness is gone. Asthma comes from inside the body, there's not something we can just take away to make the person feel better. | 808c458b-dbd5-4bea-9001-d1cd7258fdcd |
32ejyy | Why did everyone get upset when the Pope called it The Armenian "Genocide"? | Because the Turks deny anything happened. 2 million Armenians just got "lost" in the shuffle after ww1/collapse of the Ottoman Empire
Most everyone else isn't buying that story | c6f9b8b6-5823-4750-87a6-2d40229b4ffc |
8c2ems | How does water get stuck in your ear? | Am I going crazy? OP asked why it happens and everyone is giving old wives tales about how to get the water out. One guy just went on a rant about not using Q-tips
Anyway, to actually answer the question, it has to do with cohesion, aka surface tension. Little water droplets basically get into the small spaces on your ear, and are held in by the surface tension that holds the droplets together. | 33ea3bfa-ca8c-4177-bf3c-55c8caf8942f |
8a9q66 | how do fashion designers gain fame when they start out | You know how people always laugh at those really outlandish outfits at fashion shows that nobody would ever wear? That's how fashion designers get famous. They make unbelievable, over the top outfits to grab attention, then once they have it they use their renown to sell things people actually wear like jeans or t-shirts. | 48e54802-931c-4d5b-8bf8-b4454d6db113 |
53o3y6 | Why are coffee tables so low? | Most coffee tables are level with the sitting height of a couch or love seat. They are at a perfect height for resting your feet on them when your wife isn't home. | 4ef54536-43a1-4c8b-ba05-05d094d2f890 |
1yhikf | If our brains use 50-70% of our total energy, will keeping it active result in fat loss/staying leaner? | Those are excessively high percentages, but yes there is some indication that tasking the brain will burn more energy. | 1bd5a7aa-4201-47f6-a793-0f48be5942a2 |
2tpdsg | How do apps like WhatsApp and Snapchat work? | Yes, they need to have a central server.
There are various technical reasons why phones can't communicate directly with each other - but the most obvious is that there needs to be a way of storing the message if the receiving phone is switched off.
In WhatsApp, when you send a message, it displays one tick below the message to show its been received by the server, and a second tick to show its been received by the receiving phone. | 43910956-5972-4990-86f7-0152f43cca5e |
4ot74o | why do some people not 'know' how to swim and drown? | Humans are born with the instinct to swim, or at least stay afloat. It's lost after time. If it isn't taught to them or kept in their mind, they forget how to.
Not to get all preachy, but some people simply don't teach their children how to swim. They then grow up not teaching their kids how to swim, or purposely keeping them from swimming because *they're* afraid.
I think you're discounting how much effort went into teaching you how to swim from adults. | eac7b4fc-a948-43e8-adb8-247b172dbf43 |
2sxue5 | Why did this weekends reddit super story lose up votes over time? | I think people are starting to question the validity of the story. The live stream from the PI got a lot of people calling bullshit | 01844fed-a208-4dd3-b514-7ae9f86b7ff4 |
3bedzz | when did it become gramatically acceptable to put the dollar sign after the numeric as in "10$"? | I've never seen that before. Where are you seeing it? | cc93356b-6958-4629-8d31-ae834f5601f8 |
7xgwz9 | What was the possible cause of the dancing plague ,and considering the fact that this disease was referred to as a "mania", was it a physical or mental disorder? | Modern theories include (1) group poisoning with a naturally occurring chemical that can grow in rotting grain, (2) mass hysteria caused by recent problems in the area that had people afraid of starvation, and (3) encouragement from the authorities who strangely thought that encouraging it would stop it. | 2f85667b-b8e9-499f-b851-94f104173389 |
5yqdat | how did man figure out Wells? | It was just something that was learned over time.
Someone found a spring. Then water stopped coming out of the spring. Someone then dug a little big to gind out where the water went and the spring started back up. After this happens a few times someone figured out to dig in the ground to find water. | e785d796-9460-4c12-8d75-e1d763a600b1 |
343bez | What considerations are taken into account when an establishment decides to sign with Coca-Cola vs. Pepsi for an exclusive supplier contract? | Generally three things:
1) Which drinks are more popular in that area, Coke (Coca-Cola, Sprite, etc) or Pepsi (Pepsi, Mountain Dew, etc)?
2) Are there any nearby restaurants that have an exclusive agreement with one company or the other within a certain range? (This is rare; nether company has much interest in stopping *anyone* from buying their syrup.)
3) If the restaurant has a parent company, they may have an overall deal with one of the companies that pretty much mandates their outlets sell that company's product. (For example, pretty much all McDonald's and Burger Kings sell Coke products.) | ba8ebc3e-88bd-4971-b046-90cb87e805ea |
5hgfzl | Why are some traditional last names of certain descents (Indian, Greek, etc.) so long? | might wanna give some examples. but absent that i will talk on last names in general:
in most cultures a last name is either their job, who they belonged to, the first name of their father, or just something they saw when they picked out their name.
the first gives us names like smith, or carpenter, or barker, or baker, or weaver, or waulker, and other countries have those same kinds of things but in their language (like schmidt for smith)
the second gives us things like walters or richards, because the person was a slave to a man named walter or richard.
the third gives us things like fitzpatrick or jackson (son of patrick, or son of jack)
and the last gives us things like hill or river or meadows.
and we see these in other cultures too...the evolution usually follows:
you have a few people in your village, first name is fine- > village gets too big "did you want that john, that john, or that john" need a last name "i want john the smith", "i want john son of jack"- > get big enough you need third names.
so why might they be long, well fitzpatrick is already a pretty long name, for greek you might have "Giannopoulos" or "son of giannis" (note: greek seem to have a lot of things that are "son of" in different ways, like Ioannidis, son of ioannis, Michelakakis, Michelakis, Michelakos, all meaning son of michael)
and sometimes we will see last names of where the person is from, usually aristocracy or famous people...like leonardo da vinici...which is just Leonard of ~~Venice~~ vinci. or Otto von Bismarck...otto from bismarck.
so if you see a long name in some language, pretty good chance it means "son of [such and such]" or "from such and such a place" these are usually the longer names. | 1d00d9ef-2762-4f33-8bb8-09fd0d84899d |
3rw4yb | How does the ketogenic diet work, and do is actually cause more weight loss that low calorie? | Yes. Part of it is that when eating a ketogenic diet, the food you're eating is more filling becuase you've cut out starch and carbs. So people end up eating less calories anyway. | 3c181675-792f-41f7-9b4a-504d041b8c4a |
4gryx5 | What is the difference between 2nd person point of view and 3rd person point of view? | I think 2nd person is where the narrator is aware of the reader and "speaks" to the reader, saying "you will love this" or "if you didn't know" ect. 3rd person is just an outside voice of the story/text, narrating what's happening in the text. | e5fbc05c-0202-47c8-be74-c57684b11788 |
7omb6u | Why is ketchup always watery when you first use it if you continually squirt the water out? | The heavy solid chunks gradually fall to the bottom of the bottle, leaving the watery part toward the top. | c9fa841f-2226-4ff5-bc82-b87d1d5fff6e |
5z5dhe | How did the Polynesians have enough food and water to travel such great distances in canoes and why did they do it? | Carrying enough food isn't really a problem, especially 2,000 or 3,000 years ago, when there were lots more fish in the sea.
I sailed 12,800 km, from Panama to New Caledonia on a 11-meter sloop.
We left with 100 liters of fresh water for 4 adults. We caught rain running off the mainsail and put it in the tank. Never was short of water.
We towed two fishing lures the entire time. We caught good sized tuna every other day, usually two at the same time. We would catch one or two dorado every 5th day or so.
As we emptied the jars of vegetables and other foods, we would refill with fish and a court bouillon, then water-bath can the jars on the boat's stove.
We arrived in Noumea with all the jars full of fish, which were given away to the skipper's friends. | 93d7d70d-8bd0-4f17-89b4-8f286d296799 |
13hw4n | Why it's so difficult to make Xbox 360/PS3 emulators for PC. | Well first off an Emulator for a game console is a software that is replicating the hardware that is being used in the console and its operating system.
Old machines we're easy to do this with such as the GameCube and N64 because they we're inexpensive and simple machines.
Microsoft and Sony however have spent money and time protecting their software and hardware and actively do so. This makes it difficult for someone to accurately replicate their safety precautions and encryption data.
Once the 360 and ps3 have lost their spotlight and support, the hardware and software will stop receiving updates and will be easier to replicate.
Also microsoft and sony lawyers won't be so quick to threaten anyone who tries ;) | 2c8837b7-775b-469b-a7cf-bdb138c561ef |
34roks | - Why do the ads on youtube load immediately with awesome quality but then the video I actually want to watch won't load or takes forever to buffer? | The videos used for ads are stored on their own server locality in relation to your location. Since YouTube makes its money off of ads, they have to make sure the ads load. | 0946079b-3439-4f41-bed7-90b03719e86c |
1mmfcr | Why does green and blue light create yellow light, but yellow and blue paint create green paint? | What happens with combining light and combining pigment is two different things.
Essentially, a color of light is made up of the color that you are seeing when it hits your eyes. Mixing another light into the first will make you see a combination of the two lights, which increases the brightness, and lightens the color. For a good example, play around with RGB colors in MS Paint. Adding or removing different lights can cause all kinds of colors to occur.
When you have an object that is colored, what you actually have is an object that reflects that color of light, but absorbs all other light. A white object reflects all light, and a Black object absorbs all light.
So when you have a red blob of paint, and you mix Blue in, instead of getting even brighter (more light) the two colors together absorb some blue, and some red, and your eyes interpret this as purple.
So if you have a bunch of different colored lights, and you turn them all on, it will look like white light, but if you have a bunch of different colored paint, and mix it all together it will likely turn brown or very very dark. | 52e65205-88c8-49b7-9513-67eaa8dfbf79 |
4hix8b | 2 stroke vs 4 stroke engine | Four stroke- Suck, squeeze, bang, blow. Flow of air/fuel and exhaust controlled by valves.
Two stroke- Suckbang, Squeezeblow. Flow of air/fuel/oil (oil for lubrication, they don't tend to have oil sumps) and exhaust gasses is typically controlled by ports in the cylinder wall, though IIRC there are valved two-strokes. | 3ac8f22a-f591-4b53-b457-a3e029f2a622 |
32cy6z | Why does sending group texts and pictures use up cellular data, when normal texts do not? And how does a text to an iMessage group text compare to a text to a non-iMessage group text in terms of how much data it uses? | When you send a multiple messages in group text it counts as an MMS, depending on your plan and data limits you would be charged outside of that. Most plans cover Text+MMS but some companies do Text only. There is no real way to calculate the exact use beside checking data use tools in the iPhone - sincerely an Ex AT & T Tech agent | e78418db-7d9f-493c-827f-f326f5268db5 |
yony4 | Why does the water in my bathtub always go down the drain in an anti-clockwise direction? | The short answer is: "no it doesn't!". Think of it like a long pole standing without support: In which direction does it fall? The answer is: That direction where it is slightly tilted already. The water in the sink works similar: it will go down in a direction based on a small amount of movement present in the water. Only if the water is almost perfectly calm (almost never under everyday conditions) the Coriolis effect determines the direction of the circle. You can read about an experiment which eliminated other effects than the Coriolis effect in [this wikipedia article](_URL_0_). | a6aa7d3f-7d3e-47c6-95c6-3117fb9b1e98 |
26cphf | Why does salt water soothe canker sores when adding salt to an open wound often makes it hurt more? | Salt and/or baking soda lower the acidity in your mouth which can help the canker sore to disappear sooner. | a2f3f84a-5513-4409-95b6-d310f3aecb80 |
5s51e5 | Why do people with a stutter typically only have trouble with the first syllable of a word? | I suffered with a stutter. I was deaf until I was seven. The stutter isn't a problem of starting, it's a problem with fluidity. This problem just happens to show up at the git-go. | 37898640-3190-4a83-af6e-2632dc6d4d3e |
36u3r3 | Why do humans laugh? What physiological purpose does it serve and is there have an evolutionary reason behind laughter? | This is what I always think about when it comes to laughter. It's simple, a neat explanation, and it's Calvin and Hobbes so it's cool as shit. _URL_0_ | 9946a043-0a13-4644-a744-4bea8d22a44e |
1b8wih | Why are dogs so much more varied than cats? | Dogs can work for us, so we spent a lot more time and effort trying to breed specific characteristics. Sometimes these characteristics involve appearance as well. | 522048a5-4321-4e8c-8c75-41043bf9d719 |
1qycq5 | Does anything actually stop a foreign army from invading a 'Neutral' country? | The same reason you already said: money.
If any developed country gets invaded, other countries have everything to lose. Also, politics don't work that way in developed countries. Allies, treaties, UN. The UN might not do much, but the countries in the UN will have something to say about it.
So, you can invade, but when you try and get carpet bombed repeatedly, over and over by every other country, your country will be in a lot worse position than originally. Not quite worth it. | e4bb8f91-cd3b-4fa8-ae8b-5963ef147d66 |
11qgja | ; "Crony-Capitalism" | Capitalism, in its true form, finds efficient outcomes because it rewards the most efficient and effective operators, and punishes the worst by having them go bankrupt.
Crony capitalism, also sometimes called lemon capitalism, refers to the practice of businesses forming personal relationships with politicians etc. to get them to give the business special treatments - they keep the profits when they do well, but the Government helps them when they fail. | 66757a0b-0e1c-4401-a90d-135a10ad3a02 |
808b6k | What does the little ball inside a whistle do? | The ball inside the whistle is not necessary for the whistle to work but serves a purpose. A whistle without a ball has a flat tone that may get "lost".
In an American Whistle the ball rises and falls as it is pushed around by the turbulence. When the ball moves within the chamber, it creates variations within the pitch, or the trilling sound you associate with a quality whistle blast.
[Source](_URL_0_) | 16a8b6a2-af2f-422a-9796-623b0bb4fbe8 |
6pqi1k | Why bad habits are so easy to start and good ones are so hard. | Most bad habits feel good instantly. Drinking, smoking, eating unhealthy food, drugs, whatever.
That's not really the case with something like saving extra money or eating a more bland and healthy meal. The payoff for things like that are weeks/months away.
Exercise is easy to start imo, provided you aren't very out of shape and have at least a decent amount motivation. | 1a20f801-5d4c-446b-9b14-be0d3b0ed8a1 |
3il5c6 | Why is illegal immigration such a big deal? | Here's a test for you:
Next time you leave your house, leave the door unlocked.
Then, let people know your door is unlocked.
Then, come back and see what your house is like a few hours later. | df6163e1-3437-4121-a3a7-788f534689f6 |
6udfsk | Why are there so much rape in India? | Yer not alone in askin', and kind strangers have explained:
1. [ELI5: Why there seems to be so much rape in India ](_URL_3_)
1. [ELI5: Why is there so much gang raping in India? ](_URL_0_)
1. [ELI5: Why are there so many men raping women in india? ](_URL_5_)
1. [ELI5 INDIA: Why is there so much rape in India????? ](_URL_4_)
1. [ELI5: Why is rape so common in India? ](_URL_2_)
1. [ELI5: Why are men raping so many women in India? ](_URL_6_)
1. [[ELI5] What is there so much rape in India ](_URL_1_) | 7d6e6861-83a4-477f-b820-c0df9df332ae |
3vaz1a | Do service dogs know that they are helping? | They know they are doing what they are trained to do, and they know they get rewarded for it. I don't think that the concept of "helpful" is really fleshed out in a dog - they don't really understand those concepts like we do (though we like to anthropomorphise them) - but it doesn't really matter if they understand it. They do it, and it makes them happy (or whatever happy is for a dog). | 93803353-9388-4c5c-90b6-4cfab0983b49 |
24yniu | Why is the age of adulthood and consent (usually 18) a big deal in the western societies? Why is it, for example, normal for a 14 year old to have sex with a 16 year old, but not with an 18 year old? | There are many cases where a line does need to be drawn, but no bright line exists. Certainly we need some kind of age of majority, as there exists some age which is too young to understand a contract, fight in a war, run a household, make their own decisions in terms of education, health care etc. There's nothing special about 18, that's just what we chose. Anything else would be just as arbitrary. It makes sense because anything else would be an inconsistent, bureaucratic nightmare (do you register your fist period so you can sign up for a credit card? What about precocious puberty, do we call two-year-old's adults?). It's the same as speed limits, it's not like driving 30 mph in a school zone is safer than 32 mph, but we have to draw a line somewhere and 30 is a nice, round number.
In terms of sexuality, the age of consent varies widely from state to state. Some states allow teens to legally have sex with people close to their own age, even if one is a minor and the other isn't. Eighteen is just the federal number, which only applies to interstate commerce. | b6e00261-5517-4edd-803a-a5b9748e36fe |
2i3oh9 | Why most eggs in the nature have an eleptic form? | Because it's the sturdiest structure an egg can have, and all species that lay eggs that developed this trait for eggs had their eggs survive til hatching, thereby drastically increasing the number of surviving members of that species to go on to lay elliptical eggs. | ea45c267-edee-4f23-9ca5-1943404d84e1 |
1yvg0s | Why is it I can perceive light better in my peripheral vision? | This is due to the distribution of the photoreceptors in the retina (back of the eye). There are two types of receptors, cones and rods. Cones have color vision, but low sensitivity to light levels, whereas rods only "see" black and white, but are very sensitive to changes in light levels. Now look at this image:
_URL_0_
It maps the receptor distribution along the retina. The fovea is the center. Notice how in the fovea (labelled as zero degrees), cones dominate while rods are non-existent - but rods are more prominent in the periphery. Hence the better ability to distinguish light in the peripheral vision. | 23361979-bb3e-429b-8279-d3284eec4d5a |
67fn0w | What causes the "zoom-in" feeling late at night, making it look like your room is 1/10th its size? | I have posted this before...
Alice in wonderland syndrome.
I'm not sure my exact age at the time but I was around 9 or 10. I was laying stomach down on the brown velvety living room couch facing out with my left cheek to couch. Must have been attempting to nap.
I was staring at the opposite wall where the room corner meets the ceiling and all of a sudden I felt myself shrink down to doll size. The room became bigger and bigger and I didn't move any part of my body except my eyes to look around the room. The depth and size of the objects in the room kept adjusting and readjusting to various proportions.
I was so young I didn't understand the disorientation should be alarming and I felt like I could control the swing of becoming smaller and then normal size and then abnormally larger. I remember feeling like I was "in" the carpet like I was insect size. The sounds from around the house (like my grandma cooking in the nearby kitchen) seemed to ebb and flow per the appropriate "size" I was or distance I was away. I vaguely recall being able to recreate the experience only one more time but trying over and over to do so because I enjoyed the feeling so much.
I only learned what this is called about 2 years ago. Until then I kept it to myself because I thought I may have dreamed it or made it up in my childish recollection. | 86b07ebd-4153-4644-83f5-7a87bb5cceb8 |
5u7m0t | Why did the Panda species let their genes deteriorate until this bad and how are they still not extinct? | Because they have no natural predators and fill a niche which no other organism is really competing for, it makes sense to me that their senses might deteriorate over time. If a species doesn't need something in order to continue reproducing effectively, then expending energy to develop and use it becomes a waste and individuals who develop these "unnecessary" traits (perfect panda eyesight perhaps) are selected against.
Fast-forward to 2017. A massive swath of panda habitat has been destroyed. On top of just removing stuff pandas live in, this also creates patches of habitat cut apart (fragmented) by things like roads, canals, etc. and the WWF website lists this as the number one threat to the Panda's survival. On top of that there are people who hunt pandas, so we are acting as another extremely rapid change in selective pressure by introducing ourselves as an invasive predator. Rapid environmental change is hitting them while their genes are fine for the environment they were living in, but look quite bad for the one they live in now. | 721a5d64-48e4-4c2c-968a-6da31367c9aa |
2cpeh0 | Are infant deaths in hot cars on the rise, or is it this summer's "shark attack" news? | It's getting a lot of airplay this summer, most likely in the wake of one such fatality that [prosecutors think was intentional](_URL_0_). | c77baf07-2ee2-484e-b05d-2bd3250934fa |
j38xn | Chernobyl | Chernobyl was a russian nuclear power station. It was one of the earliest designs of nuclear power stations, built when we didn't know all that much about making nuclear power stations. This lead to several problems in the way it was built.
When nuclear power plants are in operation, the uranium in them spontaniously creates heat, which we use to make electricity. This is good, however they generate a lot of heat, so much that if we just left the uranium alone it'd melt (greater than 1000c).
We have what are callled moderators which allow you to "turn off" nuclear reactions when you surround the uranium with them. Chernobyl used graphite for this purpose. Graphite is pencil lead. Now, even once you "turn off" the nuclear reaction you need to keep the fuel cool for a long time whilst it gets rid of all the heat it has built up. Chernobyl used a water cooling system to do this.
Now, because this was the early days of nuclear power, there weren't many safety mechanisms, and the engineers at Chernobyl were worried that if there was a big problem and the power grid failed and you had to do an emergancy shutdown of the reactor, there wouldn't be any power to keep the water cooling system pumping water into the reactor. They worked out it'd take up to 1min for their backup diesel generators to turn on to provide emergency power.
So some bright person had an idea. The turbines that generated the electricity from the nuclear reactor would contiune to spin for a short while even once the reactor was shut down. They calculated that they'd continue to spin for enough time to provide power to the cooling system while the diesel generators started up. They decided to run an experiment to test this.
Due to a problem at another plant, there wasn't enough power in the grid, so the experiment (which would require shutting down the station for a while) had to be delayed to keep power on in people's homes. This delay meant that the experiment happened later than was expected and the people who were going to do it had all gone home. The night shift were now going to do the experiment, but they weren't as prepared to do it as the day shift was.
But they continued anyway, they lowered the power of the reactor but due to some mistakes they turned it down too much and it was so low it was almost "turned off", this was outside the "minimum safe power" they had calculated to run the experiment. They turned up the reactor as much as they could, but were still only able to get it to about 1/3 they level it was supposed to be at. So the power level of the station was turned up to as high as it could go (this mean that the graphite moderators were completely removed from the fuel). This was a very unsafe situation to be in because any sudden change in power output levels when the station was "pedal to the metal" could send things out of control.
But the experiement was conducted anyway, they turned off the turbines and let the spin-down on their own, providing power for cooling systems. The diesel generators turned on as planned and provided power to the cooling system as was predicted. However as the turbines spun-down the speed of water travelling through the core slowed down, this meant that the water spent longer being heated by the fuel. As the reactor was turned "right up" the water started to boil and created "steam voids" which are bubbles of steam. The problem is water acts as a partial moderator, so having water around the fuel slows the reaction to some degree, but steam is not a moderator, so as these steam voids formed, the reaction speeded up more and more, and more steam voids were formed.
Luckly there was an automatic system that pushed in the graphite moderator rods to counter-act the increased power from the steam voids so things were okay. However for some reason someone pressed the "emergency" button which was designed to fully insert all the control rods all at once in order to shut everything down. Usually this is a good thing but because of the way the reactor had been messed around with it was in a very precarious situation, it was right on the brink of going out of control.
The problem with pressing the emergency button was that the system to insert the rods was very slow, it took 20 seconds to fully insert all the rods. This was made worse by a design flaw in the rods. The rods weren't long enough and when they were fully withdrawn water replaced the space where the rods were. And the first few feet of the rods were made of a different material to the rest, which wasn't good at slowing down nuclear reactions. So as the rods were slowly inserted what happened is that first the water (which is fairly good at slowing nuclear reactions) was pushed out of the way, to make way for the tips of the rods which wasn't very good. This meant that inserting the rods actually increased the nuclear reaction at first, rather than slowing it.
As the reactor was already in a very unstable state this tipped the balance and there was a massive chain-reaction power spike which caused an explosion (but this was a heat explosion from the massive amount of heat generated quickly, not a nuclear explosion). This explosion caused the rods to become stuck so they couldn't be pushed in any further. This caused the situation to rapidly get out of hand, and the power levels were escalating quickly. The power levels jumped to 1,000x times the level they were when this all started.
The steam made from all the water boiling exploded and the whole roof of the building was blown off. Of course now all the water was steam there was no moderation from the water at all, so the power levels got higher still. Next there was another explosion called a "nuclear excursion" which is like a mini-but-not-quite nuclear explosion, this blew up the uranium and spread it about which luckly prevented it from doing any further nuclear reactions (it needs to be all clumped together to react).
However now there was utter devastation, the roof had been blown off the building, and unlike modern power plants there was not "containment vessel" which is a big strong "bottle" we build around the reactor to keep everything bad in. things had gotten so hot that the graphite was burning which was spreading radioactive smoke all around the countryside.
So, firemen came to put out the fires, but they hadn't been told about the radation. They bravely put out the fires and prevented damage to the other reactors that could have made things much worse. Sadly alot of them died from radation posioning.
Because of political reasons the Soviet Union didn't want to admit there had been a problem, so they tried to keep things quiet, but eventually a power plant in sweden detected elevated levels of radation and they were forced to admit what was happening and evacuate civilains. But all the time there was real problems caused by the secrecy they tried to keep. Poor famers eat food and drank milk that had had radioactive smoke landing on it.
In the end teams of workers bravely battled to contain the reactor. They dropped sand and lead from helicopters and constructed a concrete "sarcophagus" around the reactor to keep all the radioactive stuff in. They had to work very quickly and were getting alot of radation, so it was very dangerous.
The reactor has been in the concrete sarcophagus ever since. But its starting to get very old, as it was made in 1986. So there is plans to build a new protective cover. To prevent workers having to get too close, they are going to make this large arch-like cover a few hundred meters away from the site, then slide it over the plan on sliders. Then they will very quickly seal up th remaining gaps and it will be safe enough for a fairly long period to come. | d8c60b87-2779-4c0c-b299-64e1be3feefe |
7a46e2 | How were Integrals, Derivatives, Limits, and other calculus concepts originally discovered and applied? | They were discovered thousands of years ago, but the methods for that were super complex. Someone ssked Newton how he knew that earth had an elliptical orbit and not circular. So he went home and invented Calculus to explain his reasoning. | 65a3ad91-9a0d-4db3-8596-c8e11d657f75 |
5i8a6m | How do our bodies know to wake up right before an alarm or right before a bus/train stop? | So your brain has lots of nerves all smashed together in the center of you brain called the suprachiasmatic nucleus. It's a very accurate clock inside your brain! We naturally look for patterns all the time and so does the nucleus. So when you get in a pattern of sleeping and waking up at the same time the nucleus at those times release a chemical called cortisol and a few others to wake you up! An alarm clock actually causes a lot of stress, so your brain pushes those chemicals out before it thinks it will go off! | 378570d8-b7bf-4725-8828-a59f5133b599 |
48ovwi | Scott Kelly returned to earth today. How was he able to return to earth, and land in Kazakstan, by just floating in a space craft with a parachute? | The International Space Station is in orbit around the earth. It's affected by gravity, but because it's moving "sideways", it doesn't hit the earth--it "misses" and just keeps going in circles around it. You can only do this when you're going very fast.
To de-orbit and eventually land, you need to slow down. You do this by turning on your engine and applying the energy opposite to the direction you're traveling, retrograde. If you know your speed, earth's gravity the power of your engine, and how long you have it turned on for, you can calculate what effect this will have on the orbit--you can trace a path that's on a predictable collision course with earth. After your initial de-orbit burn, you don't have to do anything; you fall back to earth by gravity. Since earth has an atmosphere, you have to account for drag and the effect of the parachute, too, but you can calculate the rough landing location.
All this means is that when you burn at the right spot in your orbit and in the right direction for the right amount of time, you can make yourself land in any spot on earth that's covered by your orbit. | 5b736f19-d7a2-47d7-93e3-22933e0287f1 |
1n5cqn | Why are there so many claims of paranormal activities by people yet there had never been any evidence to support their claims ever in history. | 1. Because they're nice ideas. We die but we become ghosts, so it's a little like not dying at all, which terrifies us.
2. Because there are things we can't explain - like why do we sometimes get the chills ([Cracked did a great job](_URL_0_) explaining things that until very recently were inexplicable). Because we're inquisitive and intelligent creatures, we can't handle not knowing something, so we make something up.
3. Related to number 1, we just *want* to believe because wouldn't telepathy and aliens be cool and less boring than life? | 3a833ee4-9dfc-49bf-878d-3a90173da24b |
4fvfs5 | Whats the difference between theoretical physics and philosophy? | Science asks "how" and philosophy asks "why."
Essentially the scientists make observations, and construct theories to explain how the laws of nature interact, what those laws are, and how that explains the observations.
The philosopher looks at the scientists' work and asks, why are the laws of physics the way they are? What does that mean for our society and help us cope with the human condition? | f9f5f36d-a404-4f9e-8a44-2c3d12c9adbf |
21ayb5 | Why do Americans pay for so much for healthcare, yet other countries are able to get by without paying nearly as much? | First: health care isn't "free" anywhere. There may be no charge to the patient, but somebody is paying for it.
Second: insurance companies do not make up nearly as much of the problem as people in the thread are suggesting. Their profits are in the single-digit percentages, and their overhead is not nearly so high as people think. Regardless, insurance company overhead and profit are not nearly large enough to explain the price differential.
What does probably explain it is three things.
First, though the US health care system is slightly more market oriented than the system in most other countries, it's not really a market system. In a market system, consumers know how much the goods and services they buy cost before we buy them, giving us the ability to shop around on price and creating an incentive for providers to compete on price. That simply isn't the case in US health care. Even the providers usually don't have any flipping clue how much their services cost, and even if they do they usually can't tell you up front. No one is likely to know how much something costs until months after the procedure. Prices are completely opaque, so there's every opportunity for bloat and waste.
But second, that introduces the possibility of pricing health care as if it were itself an insurance program rather than letting insurance products do the work of risk sharing. Basically, the way insurance works is that everyone pays a bit more than they need to so that no one gets completely slammed by an unusually high expense. This is how health insurance is supposed to work, and there's nothing wrong with that. What's problematic is that in addition to that kind of risk pooling, hospitals are doing some of their own. The reimbursement for Medicare patients is usually just barely enough for them to break even, and the reimbursement for Medicaid patients is so low that hospitals almost invariably lose money on them. And for the truly indigent, they usually wind up not getting paid at all. That means that those of us with money and/or private insurance wind up subsidizing those other patients. So not only are we paying into an insurance risk pool, protecting ourselves and the other members of the pool from large losses, but we're making up the difference for the huge number of Medicare/Medicaid/indigent patients who aren't paying their fair share. And this is possible because pricing is completely opaque, as described above.
Third, the above is made worse by the fact that some of the most expensive care out there--management of chronic conditions, long-term hospital stays, and cancer treatments--are mostly Medicare issues, and most other countries are simply not willing to spend what we do on those things. The US has, hands down, the best cancer survival rates in the world. But that's very expensive, and since Medicare isn't picking up the tab adequately, hospitals raise the prices on all of their other services to compensate. Same goes for extended ICU stays for the very elderly. In Europe, such patients are frequently allowed to die a lot sooner, which can save a quarter-million dollars in only a month or two.
So when you see that $50,000 bill for a simple surgery, understand that (1) the hospital isn't actually going to collect that, maybe only $20,000 if it's lucky, and (2) a good chunk of that bill is going to subsidize other patients who aren't paying what they need to pay.
In short, it's a combination of factors, but the biggest ones are the fact that though we're supposed to be acting in a market system, there's no accurate price information, we've chosen to spend a lot on care that other countries don't, but because Medicare doesn't actually pay enough for that care, prices go up across the board to compensate. | 56b43b9c-794f-4675-96ea-4f5f60991e84 |
1yav32 | Where does all the rock salt for keeping the roads clear go? Why haven't so many areas near roads become too salty for grass, trees etc. ? | You're on the right track of thinking.
The reason areas near roads don't become too salty right away is because when it rains most of that water enters a drainage system and makes its way towards rivers and lakes. That's where the biggest issues occur as you often see fish, algae, pretty much any aquatic organism get affected. Another factor to note is the frequency at which salt is being deposited. Salting the roads one time for a single snow storm won't have as much of an effect as areas further north (or south, depending) which require salting roads once a week or more.
Some municipalities have started switching to beet juice for just this reason. | 04733951-9319-4a3d-b028-03303ca7a272 |
2dp0so | Do those phone apps that say they can save power actually do anything? | generally no.
If you take a look at what your smartphone uses the lion share of its battery for its the screen (40% to 70%). The easiest way for most smartphone users to extend their battery life is just to keep their screen brightness down and set short timeout for the screen (30 seconds) after that the phone will spend most of the remaining bulk of its power on maintaining its connection to the network when not in use (because most of the time its not transmitting) This percentage can go up if the phone has poor reception or if you spend a lot of time on a call or video.
Its a common misconception also (especially with android users) that they have apps running in the background to blame for poor battery life.
app killers have been the rage for a long time, but truthfully they do little to nothing to help. Unlike a PC a phone will not ususlly run two apps at the same time (some more advanced samsung models do this) but when you have multiple apps "open" it just means that their in a sort of suspended animation, waiting for you to open them again. this is why if you press home out of say a playing youtube video or an angry birds game it will pause until you go back in where on a PC, just changing to a new window won't do that. Music apps have to be designed with special permissions to keep running behind the scenes and are an exception not the rule.
If you are having exceptionally bad battery life (less than half a day) then the issue may be hardware related. You may want to bring your phone in to your carrier for them to look at. | b19e2dfd-ad1a-4c04-bf85-0cd9e4cc821f |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.