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bsga8y
|
How does exactly planting trees helps the environment? Is it possible that planting too many trees without planning it carefully would lead to bad consequences?
|
Hi -- Trees are part of a cycle or a system if you will. Too few trees upsets the balance in nature or a given location e.g. a mountain; here are are couple of examples that may help you imagine:
1. In tropical mountains, too few trees may cause flooding below, because soil become too loose (no roots holding them) and this damage villages or surrounding areas
2. Too few trees where animals live can cause animals to lose food; same with larger animals that eat those smaller animals; humans also eats some or depend on those large animals
3. A more complex and possibly harder to imagine scenario is that trees "trap" our carbon emissions into the soil (e.g. while they're alive and when they die). When we burn fuel, we release carbon (dead stuff millions of years ago) into the air, which causes things to warm up everywhere on earth (global warming; melts ice, makes seas higher and some land sink).
Trees also produce oxygen we breath. We obviously plant not because we already ran out, but preventing it before it becomes the case.
Again, its a cycle and a system; things can be quite complex from there and different people may have different interpretations about what happens when there's too few trees.
PS: its takes hours or days to remove trees in case there was too much in a certain area, but takes decades to grow them.
|
e0757b4a-4491-4d1f-a562-e9f6aa169de0
|
bsgaob
|
How will the Starlink satellites move from their "blob" to be evenly spaced out in orbit?
|
Let's say there aren't 60, but 2 sats, and they're supposed to be on the exact opposite side of earth. The rocket releases them in an orbit where it takes them 1 hours to circle earth, and they need to go to an orbit where it takes them 2 hours. (those are not real numbers, I just made them up) Now the first satellite starts its thrusters and moves to the higher orbit. So when the second satellite has moved around earth exactly one time, the first satellite will only have moved halway around the earth. At that point, the second sat will starts it thrusters, which will bring it into the same orbit, just on the opposite side.
It's of course a bit more complicated with 60 sats, and the timing will also not be as neatly. But it's the same principle: The sats will launch their thrusters one after another, timed just right so that they are evenly spaced apart.
|
dd490ae4-5162-42ed-b39a-72405cd479e5
|
bsgb8t
|
What is gerrymandering and how does it happen?
|
Imagine there are 100 animals, 60 cats and 40 dogs. These animals must be sorted into 20 districts, and in each district only the overall vote counts.
If we grouped 3 cats and 2 dogs in each district, the cats would win all 20 districts, giving them 100% representation even though they are only 60% of the animals.
If we grouped 3 dogs 2 cat in 13 districts, and randomly assigned the rest, the dogs would win 13/20 districts and the overall vote even though they are a minority.
Gerrymandering happens when the people who define which segments of the population belongs in which district do it in such a way it unfairly benefits one segment of the population.
It is necessary to redefine districts over time since populations can grow and new districts can be created. The best way to avoid gerrymandering is to have multiple independent 3rd parties to oversee the process, but it’s still tough to stop it completely.
|
1fcc5cf3-3cbd-42b8-9be9-9e340ba35800
|
bsgu1c
|
How does 2 day shipping or overnight shipping work?
|
Warehouses generally have regularly scheduled trucks that pick up once a day or once a week, whatever the frequency is.
If an order needs to ship faster then they generally order a truck from a special courier to come pick it up right away.
I imagine a company like amazon probably has multiple trucks picking up throughout the day and the faster shipments they probably just guarantee to be on the first truck.
Then when delivering it's the same type of priority.
When I order something from amazon with standard shipping it usually arrives in a FedEx truck. But when I order something same day or next day delivery it usually arrives in a small van by some courier company I've never heard of.
|
9a8e7c29-71cd-4cde-8085-2261e4a87f10
|
bsh4y8
|
How are muscles supplied with oxygen during exercise?
|
The right ventricle of the heart pumps blood into the lungs, where it releases carbon dioxide and absorbs oxygen. And then goes back to the heart and is pumped out by the left ventricle enter the arteries, and from there into the capillary beds. These capillary beds run through everything that needs to be serviced, including muscles. Then the blood, depleted of oxygen and rich in carbon dioxide, flows from the capillary beds into the veins and back to the heart again.
So the muscles merely work, producing carbon dioxide that they released into the bloodstream through those capillary beds, and absorbing oxygen through those capillary beds.
|
618b1428-c36b-4c10-8bff-3a9b35d08558
|
bsh5da
|
How do diseases (like the flu) have "seasons"? And how do they survive between these seasons?
|
Most of these diseases do not just live in human populations, but affect a wide variety of animals. The seasons for different types of flus are related to the periods of the Year where people are most likely to come into contact with carriers of the flu, which could be other humans or could read one of those animals.
|
fd77c243-4a38-4f14-ad2b-c1cdf14e7738
|
bshazk
|
What exactly happens when our throat gets dry and why does water almost always fix it?
|
It's pretty much exactly as it sounds like. The cells in your body require moisture to perform all of their various actions and functions. When there isn't enough produced they can get dry and signal this to your brain. If you add more water back it helps keep things shiny and happy.
|
9349615b-6965-4bf9-b855-4da3fd0a219c
|
bshb1z
|
Why does the Japanese language have English loan words for things they already have words for?
|
The words often have slightly different connotations. For example, the English loan word *kyanseru* (cancel) is an informal, modern-sounding way to talk about canceling something. If you were talking about canceling a contract or other more formal arrangement, you would likely instead use the Chinese loan word *kaiyaku*. And if you wanted to talk about canceling in a more general or abstract sense, like taking back your words, you might instead use the native Japanese word *torikesi*.
Japanese is not unique in this regard. English has many French and Latin loan words for terms that already had native semi-equivalents: pain/hurt, rage/anger, response/answer, prior/before, commence/begin, creed/belief, abdomen/belly, corpse/body, fraternal/brotherly, construct/build, etc.
|
27f41099-a4b1-48ca-8ed1-22acf9769389
|
bshhws
|
Why does our voice sound different to us on recordings?
|
Since sound is just vibration, so is your voice. When you speak, the air you exhale isn't the only thing that vibrates. The bones in your head, your skull, vibrate as well. This vibration of your skull makes the air in your ears move too, but since bones are a lot denser and harder than air, what you speak sounds a good tad lower.
When you hear your own voice on a speaker, you don't have that effect and it sounds kind of awkward because that's not what you're used to.
|
d63dcdce-9d04-45b6-a9d8-7b5b1b2e3b11
|
bshm20
|
How have Olympic gymnasts improved so much from back in the day.
|
Back then people still needed jobs, now they dont and can practice harder for longer. And science helps by showing then methods on improving motions. You cam find cool videos on youtube
|
c3f166c2-009b-4f10-8c22-ccb95945f54f
|
bsi05k
|
why do formula 1 cars need pit stops?
|
Currently, they are required to use two different tire compounds for each race, so they must pit at least once to change tires.
|
7e5c289b-fca3-439a-96fc-b9adc045bc08
|
bsi4zx
|
Why are rivers/water formations in Europe/UK so murky/dirty, can they be cleaned?
|
It’s just the composition of the ground. The water is brown because of the substrate it flows on. Nothing you can do about that without literally replacing the surface makeup of our soil.
The Thames in particular is also unfortunately a dumping ground for waste, some industrial products and other stuff. It’s not as bad as it used to be, but it’s not great.
So, no. You cant remove the dirt, it’s just the land the river flows through. It’s actually a sign of good soil and water. Many of our rivers and lakes are much better suited to aquatic life than the ‘clean’ rivers and fjords of scandanavia, there are more nutrients in it.
|
2d5cdbea-621d-41bc-96cc-03cdd121638c
|
bsi6hw
|
Why does it seem so challenging now to send a manned crew to the moon, when we were able to accomplish this over 50 years ago?
|
The best analogy I can think of is that it's also challenging to reproduce the Great Pyramid now, even though it was something that was accomplished 4000 years ago.
It's not that we don't know how to do it, it's that our priorities have changed. We're not willing to spend the money it would require, and we're not willing to take as many risks with human lives as we were then.
But we COULD do it.
|
fbb65c15-073b-4622-8707-f8853d367fd5
|
bsib0u
|
Why are pitchforks so dam effective?
|
The pitchfork works best on substances that have relatively long fibers that can interlock to prevent something like a shovel blade from penetrating into the mass. Examples are things like straw, long grass, mulch, etc.
Those long interlocking fibers keep things from falling through when the tines pick up, and the tines being pointy allows them to be inserted and removed with little effort.
|
c9a86324-c051-463b-b294-8986bafbf1da
|
bsit88
|
What’s the difference between OTC pain relievers such as ibuprofen/aspirin/Tylenol/acetaminophen?
|
Acetaminophen and Tylenol are the same. I'll refer to this drug as Paracetamol though, because that's what we call it in the UK.
Ibuprofen and Aspirin are a different class of drugs, they're part of a class called NSAID (Non Steroidal Anti Inflammatory Drugs). They help reduce inflammation, as the class name suggests. Paracetamol doesn't really do that.
To first know how paracetamol helps relieve pain, we first need to look at prostaglandins. These are lipids that are produced in the brain and spinal cord, and they're believed to make nerve endings more sensitive. The current theory of how paracetamol works is by reducing the amount of prostaglandins being produced, therefore making nerve endings less sensitive; giving you the pain relief.
Paracetamol is also really good at reducing fever, as it effects the part of the brain that helps regulate body temperature (the hypothalamus).
|
8b29e0bc-4d52-4980-8b4a-1184055dd2f7
|
bsja5k
|
Why is Teresa May getting all this hate and why does the uk wanna leave the EU so badly?
|
I'll copy and paste some reasons some Brits want to leave the EU below, as to the former question: Britain is split between remainers and leavers, remainers dislike her for trying to leave the EU, leavers for failing. The deal she negotiated was poor, and when it failed to get through parliament she neither called a second referendum (to try to remain) nor left without a deal. Instead she just waited a bit, and then called another parliamentary vote, and another, and another. When the deadline to leave came around, she asked for an extention, and then another... Eventually she was forced to leave, having achieved nothing and satisfied no one.
As to why leave: Firstly it should be noted that the reason the government are trying to leave is because it was voted for, and this not leaving would damage faith in UK democracy and see the governing party destroyed at the next election.
The reason people voted leaave though: "There are a lot of different motivations, and not all supporters of leaving hold all of them. I'll list a few below.
Freedom of Movement: Predominantly a British issue, the EU mandates that every citizen of the EU has the right to live, work, study etc in other countries of the EU. This has caused some issues, in the UK a number of people are unhappy with the level of migration from Eastern Europe to the UK. Thus they want to leave the EU.
Soverignity: One primary EU goal is "ever closer union" - essentially its slow transformation into a federal country like the US. Some people don't feel European, and thus don't want to be part of this federal Europe, and feel leaving is the only way to stop it. For example, they might want "their own government" to decide on regulations - because they do not feel like the EU is "their own".
Democracy: The EU has some issues with democracy. Its executive is not directly elected and a lot of power is held by various unelected officals through its institutions. A lot of power is also organised through countries within Europe, so rather than power being held by its citizens it is held by the German Chancellor or the British PM etc. Some don't feel that the EU is sufficently democractic, and don't think it can be reformed to be democratic, and so want to leave. Arguments on the nature of power are difficult to ELI5, since they are heavily linked to both how the EU is organised, how it actually works (i.e. including backroom deals and so on) and more philosphical arguments about democracy.
The Euro: This does not apply to the UK, except through the paranioa they might be forced to join. However it is a motivator for some continental views. Simply put, the Euro is not very stable. It links together economies that are very different, without strong safeguards. During the 2008 recession this had a devastating effect, causing a massive recession in poorer countries like Greece, and dropping much of the rest of Europe into a recession in 2010. Under the Euro southern Europe has struggled to grow, with a number of countries having not grown much since they joined. Whether this is the Euro's fault, if it can or will be fixed, and so on, are still debated. However for those who think the Euro is a problem, there is no legal way out, so leaving seems the only solution for some.
Trade: Being part of the EU removes a nation's ability to set its own trade policy - it cannot negotiate its own deals or set its own tarrifs or subsidies. Sometimes this results in deals not totally in a nation's favour. For example a country without significant agriculture might see the EU push for protection for farmers, which pushes its food prices up to protect another country's farms. Often disagreements within the EU causes deals to fail as well. Some people think that being outside the EU will allow for more trade deals, and for those deals to be better focused on that nation's interests, and thus want to leave.
Money: The EU collects money and pays it back out (like all governments). Some nations pay more than they directly receive, and thus some of their citizens feel they could save money by leaving.
Please note: These are motivations, not watertight arguments. You may see flaws in them, they may not meet your values at all (e.g. you might not care about immigration). This does not matter - what matters is that people belive them, and that people care about them, and that makes them want to leave the EU. I have probably missed some arguments. I have deliberatly ignored counter arguments since a balanced, nuanced, and in depth perspective would fill books. Also I do not agree with all of them, so would rather clarify than defend them."
|
58b523a8-c2d3-4c77-8cae-5c0564ef16ea
|
bsjm5g
|
why did Theresa May resign?
|
The Britons who want to leave the EU have been told that leaving would give them lower costs, fewer immigrants, and the same sort of government services. To deliver on this promise, anyone will have to get the EU to agree. Alas, the EU has absolutely no reason to want to agree to this. Ms. May spent many months defining an agreement the EU is willing to approve, and has failed 4+ times to get the UK Parliament to agree to it. She is giving up. People are mad at her for failing.
The real problem is that the people who made the promise, the **Leave** people, made a promise that nobody believes can be delivered upon. **Leave** promised that the EU would agree to the UK's proposed terms, and this is simply never going to happen.
Why do I say "never"? There is a special problem, Northern Ireland. NI is on the same island as Ireland, an EU member. In NI is "out" and Ireland is "in", then there must be a controlled border between them. Alas, for many years, when there was such a border, it was a disaster for the island. The Leave people claimed: a) there would be no hard border between NI and Ireland; and b) NI could remain part of the UK. These two things are mutually exclusive, unless the UK somehow forces Ireland to leave the EU also. The Brits forcing the Irish to do things is the root cause of too many Troubles for that to be seriously considered.
TL;DR. The **Leave** people sold a lie to the UK voters, and May is in trouble because she was in charge when they got caught.
|
daf0cd6c-ff9a-4811-8698-ae8c6afddf9f
|
bsjm7n
|
What is the white stuff you see under a cut
|
That would be the third and bottom layer of the skin and it is called the subcutaneous layer. It is made mostly of fat and helps your body stay warm and absorb shocks, like if you bang into something or fall down. The subcutaneous layer also helps hold your skin to all the tissues underneath it. It's composed of fatty tissues.
As a side note I would like to add: if you are harming yourself please seek help from a friend or a therapist, especially if you are cutting deep enough to see this layer. If you don't have a friend to talk to, you can message me. I will listen~ Please stay safe.
|
70bc9fac-0f4f-413f-9896-cfe3aa124451
|
bsjs3k
|
How is a currency value defined? How are projections made? What institutions take place in deciding the Representative Exchange Rate?
|
The price of a currency is just like the price of anything else; it's determined by a market.
The Foreign Exchange Market is where people go to exchange currencies. It's populated by banks or bank-like entities, but those banks are just fulfilling orders from ordinary people and companies who want to, for example, trade COP for USD. The market matches these people up with others looking to make the opposite trade (USD for COP). The relative sizes of these groups determines the exchange rate. (As a side note the "Representative Exchange Rate" is just a summary measure of market activity. Over the course of the day, the market price might go up or down a little, but it's useful to be able to say "the exchange rate yesterday was X" rather than having to recount that whole history minute-by-minute).
In your case, the market started at an equilibrium where 2.8 COP could buy 1 USD. Everyone who wanted to sell COP at that price could find a buyer, and everyone who wanted to buy COP at that price could find a seller. Then, more people who wanted to exchange COP for USD entered the market. If you maintained the old exchange rate, these people wouldn't have anyone to trade with. To get more USD-holders into the market, the new sellers needed to start offering more attractive terms, and so the exchange rate changed to 3.5 COP per USD.
Why did more people COP sellers enter the market (or COP buyers leave the market)? That's probably closer to the question you meant to ask. This could be related to how much of the currency is available - if the Colombian government is printing a lot, there will be more to sell on the market. It could also be related to economic fundamentals. How many people from Colombia are buying US goods? How many people from the US are buying Colombian goods? If some industry that Colombia excels in fails or fades, that's going to reduce the value of the COP in the foreign exchange market. I'm not an expert in Colombian politics or economics, so I don't have any guesses.
|
bd1e9801-11a2-4987-a2b4-5a69dd14b709
|
bsjszm
|
Why do tech manufacturers region lock their devices?
|
It's pretty simple, depending on the region you sell your product the highest price people are ready to pay for your device can differ quite significantly. If you have the same price all over the world you wont sell in some regions. If you have different prices and don't region lock people will just buy from the cheapest region. The "solution" is region lock.
Tl;dr: it's because of money.
|
7b066429-a581-4221-a467-253886f8ace9
|
bsjuh9
|
when the USA currency was on the gold standard how did the government create more currency for circulation. How could they buy more gold? For gold?
|
If your currency is not just backed by gold, but literally is gold, then you take gold from miners or refiners, and give them approximately the same weight in newly minted coins. That is why the San Francisco mint was opened shortly after the gold rush.
If you are on a "warehouse receipt" gold standard (which I don't think that the US was ever on), then it pretty simple. You print new money, and you use that new money to buy gold. You put the gold in your warehouse to back the money you had just printed.
If you are not on that type of standard, it is even easier. You just print money and promise to exchange it for gold, and hope that not too many people ask you to actually make that exchange.
Of course the government is also collecting taxes, tariffs, etc. This would be in gold, or in things that can be exchanged for gold.
|
e93a618e-e37e-42f5-9259-428b4f6b23cb
|
bsjxlo
|
How does a Lava Lamp work?
|
The “lava” heats up and expands slightly decreasing its density. Which it is already close to the rest of the liquids density. When it becomes lower than the other liquid it starts to float which moves it further from the heat source and then becomes more sense and causing it to fall back down.
|
bb5a5da8-0cdb-4d07-8834-f963a91c7ecf
|
bsk10z
|
Why is the frequency of light constant during refraction?
|
The frequency of a photon is a property of the photon, the amount of energy with which it was created.
Refraction preserves this property, or else the process of focusing light would change its color. To understand how, you need to look at how light passes through a "transparent" medium.
In a vacuum, it's easy to be transparent. The photon moves along, unimpeded, because there aren't any atoms to interact with. In water or glass, things are different. A photon interacts with the electrons around an atom. This interaction exchanges energy back and forth between the photon and the electron. It's complicated, but in the end the photon (actually a new photon, but we're ignoring photon serial numbers here) ends up with all the energy it started with. This allows the light to pass through without being absorbed†. Since it leaves with the energy it started with and the frequency depends on the amount of energy inside, the light remains the same color.
† Of course, some is absorbed because water and glass aren't perfectly transparent like vacuum is. However an individual photon is either absorbed or not.
|
3d85e7ea-dbf8-4d44-9c1b-9581bab6335a
|
bsk24v
|
What’s the argument against background checks for gun owners? It feels like a good safety procedure, kind of like getting a license before you can drive, but I have to believe there’s a good reason for people not wanting them.
|
Many people in the US feel that the reason for having civilians be able to own guns is to prevent a tyrannical government from taking control, because the citizens would be armed and able to stage an effective rebellion. So, they feel that government regulations on guns are not only against the spirit of the Second Amendment, but that anything that gives the government a registry of who owns a gun means that they'd be better equipped to stop said theoretical rebellion.
|
b9a64459-ab51-47b4-a6e3-8ae9862fd06d
|
bsk2p8
|
Why does our brain see everything upside-down?
|
It doesn't. It's a misunderstanding of the situation, really.
Because our eyes use a lens to focus incoming light into a clear image, the image that hits our retina is "upside-down", exactly like what happens in a camera or telescope.
The misunderstanding is this idea that our brain takes this crazy upside-down image and works its magic to flip the image correctly.
It doesn't need to. Simply enough, the top part of our retina is just treated as the bottom of the visual field. It's connected to the part of the visual cortex that expects the bottom of the image. It's all handled by the "wiring". No transformation is needed.
It's just like a camera sensor. The top of the image just happens to be physically located on the bottom part of the sensor. There's no reason to make the top of the sensor the top of the image and then require a microprocessor to flip it around. (Although we *can* do that and in fact this is very common with phones because we can hold them in an orientation, and redefining the top or bottom is convenient.)
|
abc4aecc-1296-48a8-9e72-5b945b6eb8f7
|
bsk7gh
|
what is the difference between light coming from a light bulb and light coming from tv/smartphone/computer monitor screen ? How do they shine ?
|
Light bulbs are not at all the same. Some produce light from heat (like incandescents), others from electrically stimulated gas (like florescents) , and others from direct electrical effects (like LEDs).
TVs, smartphones, and computers introduce even more choices, cathode ray tubes blast electrons into emissive materials, but they also use LEDs like light bulbs.
|
7d86b81f-bef7-4909-aaaf-437afe60c917
|
bsk94j
|
how do Shakespeare directors cut as much as half of a script from a production and have it still make sense?
|
Almost any script has a lot of extra stuff in it which is not crucial to the plot. This is not unique to Shakespeare. You could probably convey the plot of most plays and movies in just a few scenes with a few lines of dialog each.
PETER PAN:
SCENE 1. INTERIOR, WENDY'S ROOM
Wendy: I'm bored.
Peter: *enters through window* Hello! I'm Peter Pan, a magical boy who can fly with the help of a fairy. I lost my shadow, can you help?
WENDY: *sews shadow back on, improbably*
PETER: Come with me to Neverland for an adventure!
Wendy: Okay. I am going to bring my brother and sister and whoever the fuck else is in the story, I forget
SCENE 2. EXTERIOR, LOST BOYS CAMP
Peter: Welcome to the Camp of the Lost Boys! We are all orphans who live here in Neverland and never grow old. Our nemesis is Captain Hook, a pirate whose hand I fed to a crocodile.
Wendy: Okay. I'm a teenage girl so in accordance with our Victorian gender roles it is my natural instinct to be your mother.
Lost Boys: Okay.
SCENE 3. EXTERIOR, PIRATE SHIP
Captain Hook: Peter Pan I have absolutely had it up to here with your nonsense and I am going to kill you.
Peter: *throws Hook into mouth of crocodile*
Wendy: I'm over this whole scene too. Please take me home to London or wherever.
Peter: Okay.
SCENE 4. INTERIOR, WENDY'S ROOM
Wendy: I forget if there's a moral or other satisfying resolution to this story, but I guess this is goodbye.
Peter: I must wave goodbye, but don't you cry - I'll be back each Christmas Day! *exits via window*
*roll credits*
|
50fe6607-b665-401b-b04b-44e9c2220fae
|
bskdqq
|
Why does inhaling more smoke over time allow you to inhale smoke without coughing?
|
The smoke eventually burns away the cilia, small hairs in the throat and bronchial tubes, that help your body know when something isn't supposed to be there. Like smoke.
|
7ddb48e9-4186-4ef8-b513-79a3f55a3062
|
bskgh7
|
Since heroin is such a hot topic and is illegal to use in the US. Where does it come from?
|
Based on your comments you are asking where the poppy plants that will eventually be processed into heroin are grown.
If that is correct then Afghanistan is your answer.
[Afghanistan is the world capital of opium; estimates peg its share of the global opium production at between 75 and 85 percent, with an estimate of nearly 500,000 acres (200,000 ha) under cultivation as of 2016.](_URL_1_)
[Also here is an interesting history of Opium that gives more information, note this is coming from the DEA.](_URL_0_)
|
a196d25c-d6f9-40ea-ae4e-7d04848710df
|
bskgk6
|
Help me understand why we can't see stars in pictures taken from space.
|
You can see lots of stars in pictures taken from space, that's all the Hubble Space Telescope does.
You can see stars in pictures taken from the ISS, as long as the Earth isn't in the picture ([my favorite](_URL_0_ )). The Earth is really bright, particularly during the day. Cameras, and eyes for that matter, can't image a really bright thing and a really dim thing at the same exposure. That's why when you look up during the day, you don't see stars. The stars are there, but the sky glow (the blue scattering) is brighter than the stars.
|
4372769f-80a3-459b-9766-ff13217e5870
|
bskk1k
|
How do those cables they string across the road measure your vehicle speed?
|
if I am thinking about the same cables you are thinking about they aren't used to measure speed they're used to count how many cars are going across the road they use it to know how much maintenance or if they need to expand the road to handle more traffic.
|
1fd87621-afb6-42b8-9b80-dc35883b9a3e
|
bskurg
|
So my boyfriend stabbed his thumb pad pretty bad awhile ago and now theres this hard lump around where it was cut. Any explaination of what it could be?
|
It's probably a scar, but a cyst is also a possibility. I got stabbed with a pencil in grade school, and the tip broke off in my arm. In spike of hopes the body would expel it, a cyst formed around it and it had to be cut out, years later.
|
829ab70e-733f-4db0-9084-fd4cbbbd013c
|
bsl0hw
|
if I place both waters into a bucket from where the two oceans meet but don’t mix, why do they mix just fine in the bucket?
|
The idea of "two oceans meet but don't mix" is more or less a myth. Most of the pictures of this you see on the Internet are at rivermouths or headlands, where a sharp contrast between water types is visible ... but it mixes away pretty quickly.
Tom Scott did a video on this recently.
_URL_0_
|
65f9ef71-9b80-4f45-aecc-e0f0f30f3cb9
|
bsl1hc
|
Why is it so irresistible to put your feet up when you sit down?
|
It removes stress from the back and moves you toward a fetal position. Both can be very relaxing.
|
7788f7b8-d308-493a-b4b0-80ac15bd418b
|
bsl2aa
|
Why is it so dangerous to have metal in or around your body when getting an MRI?
|
MRI is Magnetic Resonance Imaging.
That uses giant fucking magnets.
Those attract metal object with great amounts of force.
Metal object inside of you + giant magnet outside of you = bloody metal bits ripped out of you.
Get the picture?
|
99a14564-a2e9-4c63-804e-a6b7d7c66004
|
bslgnq
|
Those urinal cakes: what do they do? What are they made out of? How are they made?
|
They are made from para-dichlorobenzene, a strong-smelling chemical which slowly sublimates into a gas. The purpose of them is to cover up the smell of urine, and it serves as a disinfectant.
|
177fd5f6-d27c-4d9d-8dd8-7dc198ab9cf4
|
bsllam
|
How do clutches work on powerful machinery?
|
They basically scale it up, usually with more friction disks. Instead of just one being sandwiched like in a normal passenger car there can up to a dozen. The more surface area you have the more holding power you get with the same clamping force.
|
8d24ded0-b8e2-4ccf-b56f-e2fe4d8ce9a7
|
bslqw0
|
Why do some batteries use kWh to define the capacity and other batteries use mAh?
|
Single cell batteries are typically rated with mAh since their voltages are always the same. IE: Lithium batteries are almost always 3.7v. A, D and C batteries are always 1.5v (Or 1.2v for rechargeable ones). So watts don't really matter as the voltage will stay the same.
Where as multi-cell batteries like those in hybrids and EV's consist of several batteries wired together, which changes the voltage. These are usually rated with kWh since their voltages will often be different. Most EV's use around 350VDC, and most non-plugin hybrids are around 250VDC.
& #x200B;
PS: There are still multicell batteries such as some 12v and most 9v batteries that use mAh or Ah, but that's a common size of battery. So the voltage is still the same.
|
1cbae478-ccf8-4b85-96ae-ad938ef128ee
|
bslxuc
|
How are commercial chicken eggs so consistently produced?
|
Commercial eggs are sorted by egg and quality into "grades". Different grades and sizes can be purchased at the store.
Lower graded eggs are mainly lower grades because of appearance, so these can be sold to commercial food producers who (rightfully) don't care what the egg looks like.
|
53610fcb-c009-4032-a932-c42b26e3b8e8
|
bslycj
|
what is the core of the Earth made of, how does it stay molten, and what would the impact of it cooling be?
|
As best scientists can currently tell, the core is made up of a nickle-iron alloy. There is a solid inner core and a liquid outer core.
The liquid outer core stays molten simply because it lacks an easy way to cool. The Earth's mantle and crust doesn't provide very effective heat transfer from the core out to space so the outer/liquid core stays hot simply because the heat has nowhere to go.
As far as what would happen if it cooled, well it's actually a question of when. The earth's core is already cooling, and has been for billions of years. When the core finally cools fully, many things will happen, basically none of them good. The earth would lose its magnetic field and tectonic plates will stop moving are among the two biggest, both would essentially make the planet uninhabitable in the long run.
Fortunately we still have several billions years before this occurs.
|
13e3a24d-18af-4015-b11e-82dd20348972
|
bslzj9
|
How does a "draft" of cold air really work?
|
If you have a perfectly sealed room, opening one window means air can only enter exit from that window. The incoming air is resisted by the pressure of the air already there.
With two opposite windows open the incoming air can push the air out the other side.
|
8eedba49-3596-4f8b-adcd-3526ff13f941
|
bsmdx1
|
How Much Electricity Can I Produce With 10000 Liters Of Water? (Hydropower)
|
Depends how far the water falls.
Hydropower converts potential energy to electricity. Potential energy is mass X force of gravity X height. Hydropower is around 90% efficient so we multiply by 90/100.
10,000 litres of water weighs 10,000 kg So for each metre it falls you'll produce 10,000*9.8*.9 joules.
So that's 88.2 kilojoules or 0.0245kwh. If you take it to the top of a 100m hill, you'll get 2.45kwh.
|
3bc160af-9987-46c1-8035-04b398d9e744
|
bsml2x
|
Why the bass is so important to music in general, even though it doesn't sound loud in most songs?
|
Depends on the music you are listening to. Most pop songs will have the bass ride the root notes. Bass players job is to keep time and out line the chord. So that in genres like rock, jazz, blues, etc the other instruments like piano, guitar, horns can solo and improvise. Jazz music is a great example. Bass “walks” the chord progression while keep time with the drummer, keeping the overall feel and rhythm while the improvisation is done.
Check out Miles Davis “So What”
|
15de401e-528b-4b12-bd89-331f31a0b365
|
bsn1gl
|
What determines whether someone is a “match” for organ donation?
|
The organ donor foundation (I don’t remember exactly what it’s called) has criteria that an organ donor needs to meet to qualify to even be a donor.
Additionally, the blood types of the people also need to match, and the donor has to be healthy to be able to give their organ (unless they’re dead, in which case the cause of death would need to be something that wouldn’t transfer to the one receiving the organ).
I’m sure other stuff factors in too, I’m not an actual doctor this is just what I know from doing my own research and being in science classes.
Edit for some minor spelling/formatting errors
|
4904b0e1-dfe8-41d0-8cdc-0acd9ee41751
|
bsnagp
|
How did physicists figure out the structure of an atom at a time when it was impossible to observe them?
|
The first experiment was done by Geiger, Marsden, and Rutherford.
Basically, they shot alpha particles (a helium nucleus, so 2 protons/2neutrons bound together) at pieces of very thin gold foil. The idea is that charged particles like the alpha particle should get deflected based on the electric force with other charged particles.
The particles get deflected in a way that suggested a positive core, and a cloud of electrons. Basically, most of them did nothing, which tells you they "missed", but when they did deflect, it was for a pretty large value.
At the time, the dominant theory was actually a smeared mush, the 'plum pudding' model.
Neutrons came later- they were harder since they don't have a charge. But we knew something was up, because the protons didn't immediately repel each other. At first, people thought there must be electrons in the nucleus to handle things, but it didn't match up with data. It was discovered by Chadwick in 1932, where radiation experiments he did had nuclei that ejected neutrons (which are chargeless, but still have mass etc, so they're detectable).
> when it was impossible to observe them?
In most cases, we don't observe them like you would normally think of them. We use similar techniques to the Rutherford experiment, just a lot more refined, and then reconstruct an image from it.
A lot of small scale physics works roughly on this idea. If you want to study something tiny, you find something roughly the same size and hit them against each other. Then try to back your way out of a reasonable model
|
917d102b-7bc1-40e3-a73f-452499ef6dae
|
bsnahe
|
How does a RBMK reactor explode?
|
Reactors use really hot water that’s maintained at a constant pressure as a coolant.
The pressure prevents the water from boiling at its normal temperature.
If there is change in this balance and the water turns to steam in the “primary coolant loop” the water becomes ineffective as a coolant.
The reactor gets hotter and so does the water. More heat, more steam. This causes a feedback loop and eventually something in the system will break down.
|
cf9b670e-8a62-48a5-ba75-f270ba90b1e7
|
bsnc8g
|
How come it feels so much better to sit with our legs up on a surface than down on the ground?
|
Lifting your legs up helps the veins in them release pressure that is created by gravity pulling the blood down into them.
|
71975ccc-5f5f-4fc0-b431-2002e0f1fc5e
|
bsndny
|
How do they turn black and white shows into color?
|
1. Take a colourfully vibrant picture.
2. Turn it to grayscale
3. note which colour turns to which shade of grey
4. apply it in reverse to an originally grayscale picture
5. profit
|
5919da45-b179-4c1a-8c91-0352f84ec0f5
|
bsnkn2
|
why do people have centrists?
|
Centrist is just another word for having a variety of views regardless of where they fall on the left right spectrum.
The extreme left and right hate centrists because they're both purity cults which demand perfect adherence to their side and anything outside of that is blasphemy.
|
02da86fb-9801-4fb3-a613-c566aaac8ced
|
bsnuw7
|
Unitary Executive Theory
|
It's the idea that the president of the United States has unlimited or nearly unlimited powers to control the executive branch of the federal government. There are different interpretations as to how far this power actually goes. The most extreme interpretation give the president near dictatorial power, especially in times of war or crisis, and that nothing the president does can ever be illegal by virtue of simply being the president.
|
94a47246-e004-40b5-94eb-38575b6e3cfe
|
bsnxd8
|
How did ancient people eat or even have teeth without any efficient way of cleaning them? Did they get toothaches and cavities often?
|
A lot of the world still uses a tree branch to clean their teeth.
_URL_0_
It's a neat experience, but as a Westerner, feels odd. Aside from. Using things like that, the bulk of modern dental problems are directly related to our diet. Heavy in processed starches and added sugars which stick to the teeth and allow a biofilm of harmful bacteria to form.
Traditional diets based on fruits, nuts, meats and whole grains have fewer dental issues. But tooth decay and other stuff was a common problem.
|
7a103a34-8085-4361-a4df-99b0d75cf4d3
|
bso2rf
|
how did saying 'shhhhhhh' become the way to get ppl to be quiet?
|
When I had a new born kid they told us to shhh to calm our child. Was told it is similar to the ambient sound in the womb so babies are comforted by it. So maybe subconsciously some of that calming is in all of us and it makes us be quite.
|
8c74dfcc-24dd-4447-a776-f30f8a6d1c75
|
bsocwx
|
Why is it when Chinese words are spelling with Roman letters they are spelled like that?
|
> It's pronouned Shay-Shay
It’s not. How an English speaker pronounces “shay shay” is completely different from how “Xie xie” is pronounced. Pinyin was designed to write down Chinese, not how Chinese sounds to an English speaker. “X” represents a sound that doesn’t exist in English, likewise for “Sh” and “q”. The vowels in this example are different as well.
|
a5d94ace-4e42-4eab-863b-0065758bdf7f
|
bsofv4
|
Why do documents say "any and all"? What is covered there that isn't covered by just saying "all"?
|
In the old days legal stuff was written in latin. When writing it in english was new they would put the english word but then always say the latin word too. At some point that mutated into skipping the latin and just writing everything with two different english words. So there is dozens of examples of legal terms that are just the same word twice.
"any and all" , "cease and desist" , "terms and conditions", "law and order", "null and void", "will and testament"
Sometimes the words mean slightly different things, and there is a point to it, but a lot of the time it's just "this is how legal words are supposed to sound so it's 'breaking and entering' instead of just 'breaking into'"
|
c750cfd4-d65a-4153-8227-41a603138d05
|
bsofw1
|
what's the scientific reason behind blue balls
|
Wait what? I've lived my entire life thinking "blue balls" was just a euphemism for sexual frustration or a "so close" frustration. It can cause physical pain???
|
b97ada9f-ea77-41a6-a89f-43a8d01288fe
|
bsoi7m
|
The difference between old landline phone calls, cellphone calls, VoIP and calls made through social media sites
|
I'll give it a shot.
Back in the day old landline calls came to your house over dedicated copper wires. These even ran a little bit of current which would ring the phone, which was why hard phones like that could work without electricity - they had a little bit of electricity to them already. Old phones had microphones and speakers which worked with electromagnets to produce analog signals that came over the copper wire.
Cellphones are essentially two way radios that work from local cellular towers. Network speeds like 2G, 3G etc. refer to the frequencies that are used to transmit the signals through the air. Your cell phone connects to a nearby cell tower, and as you move around your signal gets handed off from tower to tower (which explains why calls get dropped.)
VOIP are straight up digital calls over the internet. Your voice gets converted into digital packets and routed over the internet. You can use a VOIP "box" like Vonage which may plug a regular phone into it for at home use. Or you can even use a VOIP app on your phone. This app would place calls using a WiFi network on your phone, or if you were out and about, it could even use your phone's data network. In this case, though, the VOIP app on your phone would encode the audio into digital data before sending it onwards.
I'm not sure what social media sites you're referring to, but most likely those are also simply VOIP calls just with a dedicated client.
|
b8519254-42c1-43f7-9399-80966a6fd025
|
bsojbj
|
Why is bacteria so quickly becoming resistant to antibiotics and yet cooking your food still effectively kills all the bacteria?
|
Imagine you're in the army and you have a tank. The enemy is trying to disable your tank. First they sneak in and cut the fuel line and the tank is disabled. You see this and move the fuel line so that it isn't readily accessible and is protected. This is resistance.
There is another way to disable the tank. You could drop a nuclear bomb on it. This is cooking.
|
fa382938-4885-4a91-8bc9-43ab66d6768c
|
bsokkx
|
Why do the calculator and the phone not share the same number placement/ pattern?
|
Both layouts were a result of a need to increase efficiency/productivity in their respective industries.
The calculator layout was made for bookkeepers and found it increased their speed and efficiency.
The phone layout was made to decrease the amount of wrong numbers that were dialed by people using phones, as that layout appeared to be more easily understood by most people and re-directing calls made to the wrong number caused increased workload on phone operators.
Maybe I take for granted that I grew up with regular phones and texting with T9, but I never considered it would be challenging to switch between the two.
|
d314ff5e-b85f-486a-ac7a-f26e10673b7e
|
bsonm6
|
How are Native Americans so tan, if they migrated to North America from Siberia through the Bering Strait?
|
Cause they weren't caucasians...nor Chinese Han.
If you compare Native American vs Siberian, they're not that far off
|
4bb1b687-52bb-4e38-b333-3e73c67bc819
|
bsoq3c
|
How the hell does 4chan work?
|
4chan is split into boards based on topic. In a board, people can make threads by posting an image and a message. Users post on these threads, usually anonymously, but depending on the board users can either be assigned a random thread-specific identifier, or they can opt to use a "tripcode" which essentially functions as a username. Every time a thread is posted on, it is brought to the front of the board, displacing all other threads backwards. When a board is full (most boards are relatively limited in the number of threads they can have), the farthest-back threads will be pruned, either being deleted entirely or archived, depending on the board, or, if the board doesn't automatically archive, whether anyone else set up a tool to archive it.
|
267b5751-f601-48a8-baeb-fb7edd1b3321
|
bsos65
|
Why don’t tattoos just go away? If it’s just staining your cells and the cells eventually die, wouldn’t it just disappear?
|
The ink goes into a deeper layer of skin than just what's on the surface, so it holds for much longer. Some colors do fade faster than others, and tattoos on certain parts of the body (like on the palm of the hand or inside of a lip) will not last as long as others.
And they can get faded faster through unprotected exposure to the sun or other sources of UV light.
|
c4d235e3-6c33-4c4e-8802-135ae292556a
|
bsoxlt
|
How does exercising improve immune system?
|
No-one really knows. Statistics does confirm that it does improve, but how exactly, there are just theories. The most likely one is stronger heart muscle and better circulation/blood filtration.
Exercising results in better bloodflow, so blood moves white blood cells around body quicker and easier (no clogged arteries etc). They fight most external intruders in your body, like viruses and infection. Sort of like buying paramedics a faster ambulance car and clearing up traffic beforehand.
Exercise is known to improve all parts of your organism, so it becomes more like a well-oiled machine, and each part does its job to fight disease, from metabolism to circulation to breathing to mental state, so benefit is more likely cumulative than result of one particular thing. It's hard to not speculate on this particular question, science is not set in stone yet.
|
0d9e1c0b-319d-47af-a52a-50766bbc55c9
|
bsp2oy
|
How exactly does a planned demolition of a building work? How do they pick where to put the bombs?
|
They've studied structural engineering and demolition for many many years in order to know where the load bearing beams are and how a building is constructed (based on the blueprints), so they know where to place the explosives and in which order to detonate them so that the building collapses in on itself.
|
95d5c4d7-5e2c-4172-af2e-d4e78870dc5a
|
bspf77
|
Why do certain foods such as soup and sausages “blow up” in the microwave?
|
Pressure, essentially. Microwaves cause water molecules to vibrate, which displaces air bubbles. Heat also causes air to expand and rise to the surface. So the tiny bubble that was at the bottom, gets bigger as it heats up and moves towards the surface. Then, the surface tension of the soup in this case, breaks and flies everywhere. With sausages it's pretty much the same thing except the air has a harder time escaping out of the casing so the usually just explode.
Edit: The vibration causes the water molecules to heat up
|
4dc78525-060a-4afa-a0bf-db428495b856
|
bspy8m
|
Why do larger capacity SSDs have better read and write speeds than smaller ones?
|
Higher capacity SSDs are very similiar to lower capacity SSDs (for the same model), but have more flash chips to store data. The controllers in SSDs can access these chips in parallel, at the same time, and so can transfer more *total* data to more chips in the same amount of time, than they could with any chip individually.
|
aa0debad-ecf8-427b-934e-dee6cc3f8453
|
bsq3a4
|
how come when you eat food too fast you get the hiccups?
|
Biologist here!
Fun question!
Basically when you eat or drink too fast it stretches your stomach quickly, that irritates the diaphragm muscle (the one that controls breathing basically) and it starts to spasm, causing hiccups!
|
f633893b-eba0-4809-91d9-e8fbae5901da
|
bsq3gi
|
Torque?
|
So in classical physics, an applied force, F, causes a mass, m, to accelerate at a rate, a. And we express this as F=m*a. This describes the linear motion of a mass with a force applied on it.
With rotational motion, we have a derivative of that equation where a torque, T(tau), causes an object with a moment of inertia, I, to accelerate rotational, a(alpha). So we say T=Ia.
So basically, torque is just the rotational analog of force -- it is the force that causes rotation. And the reason it's important in cars is because the engine or motor will do work on the driveshaft which turns the axles which in turn apply torque to the tires which ultimately get you rolling.
The more power your engine has, the more torque it produces (other factors affect this too not just engine power output), and the faster you will accelerate. Since in a car the rotational acceleration gets translated into linear acceleration because of the fact that we roll on a straight surface.
|
b0b8e376-4380-4e9b-9e0d-af228a5dd17c
|
bsq3hq
|
How are two notes the same on different octaves?
|
The frequency of the lower octave note is one half that of the higher octave note, meaning that half of the peaks and valleys of the sounds waves align.
That's why they sounds alike and are considered the same note.
|
e23687e3-a0b8-4c07-b7e9-74b253ffa88e
|
bsq5ep
|
Why is it that tunnels and bridges don't rip themselves apart if the land is constantly changing and shifting
|
That's what the engineers do, is identify fault lines and make sure the tunnels don't pass through any of those areas.
And no, the Chunnel is through one solid area of rock, and none of it is shifting. Besides, it's 250 feet below the bottom of the channel so there isn't really any way that a collapse or fracture that huge could happen.
|
387105d4-7ca7-4cb1-9665-a589870a449a
|
bsqbv9
|
Are emotions like laughter conscious or unconscious actions?
|
There's not really any universal theory of emotion but rather a few with different explanations for it, some say it's a conscious thing while others say it's subconscious.
James-Lange theory says that a stimulus/event triggers a physiological response (PR, i.e increase in heart beat, sweating, etc) which is then subconsciously interpreted and lastly leads to an emotion.
Cannon-Bard theory says that emotions and PR happen simultaneously due to trigger events with no room for interpretation (this could be considered as happening subconsciously).
Schacter-Singer theory says that a PR occurs due to a trigger event and is consciously appraised/labelled and then leads to the appropriate PR. An emotion is then experienced based on that appraisal.
The Lazarus theory suggests that we appraise/label a stimulus/event and then experience the appropriate emotion and corresponding PR at the same time.
|
d3e654ed-1def-48f3-9d3c-d438f29623a6
|
bsqdmi
|
- Why do baby teeth grow in relatively straight, but adult teeth grow in so crooked, requiring braces?
|
Babies have less teeth than adults which leaves more room for them to grow in correctly. Once adult teeth start to grow in sometimes the additional molars make the front teeth crowd.
|
2ee5c925-095e-4362-8ced-2ec2417c86c4
|
bsqj8t
|
Why do out bodies get random chills for 1 second?
|
Nerves are not exact wires like the electrical connections in a computer are. They are basically tubes with a mix of chemicals, hoping that the electricity gets through. Sometimes there is a glitch in the ratio of this chemistry. This causes a wave of electricity to rush through a part of them all at once. It is in some way like a reset is for computer, it clears the wrong information out, so your nerves there can work again correctly.
When similar thing happens in the wrong area (i.e.: inside the brain, not somewhere around the butt), person can get an epileptic seizure from it.
|
4e144dcd-a078-4d7e-bea3-07d092f08cd3
|
bsqx4f
|
- Why is all lint blueish grey?
|
Dark colors are always gonna be the most prominent of colors, regardless of what you have. Multiple colors at once make darker stuff, and a lot of the fluff that comes off in the dryer are very thin/small bits of color, when combined tend to make grey.
|
a69d1b6e-1d31-4707-8636-ce63e9049aa0
|
bsr62o
|
Why is there no standardization of the dimensions of Baseball fields outside of the infield?
|
I would imagine that it has to do with the space a ball park sits in. Major league stadiums are massive and there are plenty of older ones that are in the middle of major metropolitan areas so space now is at a premium. My best take at it.
|
91ebbf75-0721-4292-9f06-898db7d919d4
|
bsrhdp
|
Why are MLMs still as big as they are even though pyramid schemes are illegal in many countries?
|
The difference between a "pyramid scheme" and an "MLM" is that in a pyramid scheme, *there is no product* - the only thing you're "selling" is entry into the pyramid scheme, which does absolutely nothing at all other than move more money to the top.
In an MLM, the money still moves to the top, but when you pay into it *you get something*. This makes it legal because it's just like buying a product anywhere else (except for a lot more than it's worth and with a much lower chance of being able to resell it, but as far as the law cares, that's *your* problem).
|
99089fb2-33c4-4a6b-8a76-848561293041
|
bsrjkj
|
How did the talks of war with Iran rise so quickly and what are the underlying causes?
|
Watch the movie [Wag the Dog](_URL_0_). The idea is to distract the public from the Mueller report long enough that it's not in the news anymore. A really common tactic used in politics (on both sides) is to divert public attention on a minor crisis towards potentially a seemingly major crisis (albeit a completely invented one).
Don't worry about war with Iran until there's an actual death count -- it's pretty easy to fake at-sea skirmishes ([it's happened before](_URL_1_)) but a lot harder to fake actual soldier deaths.
|
71a47a79-eb8f-4cd2-a4ae-b8b47e496fa5
|
bsrmh4
|
How come the iron in our blood doesn't seep out during an MRI scan?
|
Because they are not simply iron ions dissolved in water, but they are bound to the enzyme [Haemoglobin]( _URL_0_). Basically, they're part of a much larger molecule and shielded by the enzyme.
|
eb1fed59-9caa-4b7f-ad33-c3cfb79cb542
|
bsrpk2
|
What did the KGB do during the Soviet union?
|
I acknowledge they use inhumane methods (and I'm not apologetic for what they did, just stating what the did), but it is basically the "internal security" for the Soviet Union: safeguarding the Soviet Union against perceived or actual threats like political dissidents, nationalists/separatists, and, terrifyingly, anything they suspect to be "anti-Soviet" in nature. They also conducted foreign intelligence services (instead of just national intelligence services like counterintelligence). Think of them as an amalgamation of the FBI, CIA, NSA with none of the oversight or holdback that those US three-letter organizations have now.
& nbsp;
& nbsp;
TLDR: they were a brutal and inhumane organization that served the Soviet Union's interests, not just a mere security service to protect the now-defunct Soviet Union, and that they "protected" the Soviet Union from within and without.
& nbsp;
& nbsp;
PS: Happy cake day :D
|
29891b2f-981b-4e3a-9608-f9b97e9e200a
|
bsrssx
|
why are they called 'wisdom teeth'?
|
I'm not a dentist, or a linguist but it's probably since they only come when you're older, hence wiser?
|
6e880c14-2b5b-4701-ab54-ef1467cd6005
|
bss5dn
|
Why has split screen gaming disappeared?
|
Because Internet. You can just play games online and be able to see the whole screen. Many times you don't need to be huddled around a game console with your buddies playing split screen.
|
8d9743e7-b9fa-47a7-b311-0bd1e75c64a6
|
bsshlf
|
Why do some countries have super deadly animals while others dont?
|
Deadly animals live in all habitats. Before humans were around, there were deadly animals virtually everywhere in the world, save for perhaps a handful of deserted islands.
As humanity grew and spread, and learned how to defend themselves, animals also learned to keep away from human populations. For this reason the countries with large predator populations are generally the ones with large, mostly uninhabited spaces. The countries with high population density and few places more than a few miles from human settlement are generally the ones with no pllarge predators anymore.
One other factor to consider - especially in Europe, as society grew more advanced and more organised, there was in the last few centuries a growing trend of hunting and culling those large predators. That's another major reason why Europe has very few dangerous animals in the wild.
|
327f5c71-4a8d-45bb-8488-92daa7d08d44
|
bst0hd
|
How touch technology works?
|
Conductivity.
There's an electric field across the whole screen. Your fingers are conductive, so when you touch the screen, some of that electricity drains away. The device has sensors all around and so can tell how far across and how far up that screen that happened.
That tells the computer exactly where the touch happened.
|
5702d010-a367-4dd3-985f-cbe67a859ddf
|
bst77c
|
why do certain containers cause the liquid to disastrously pour down the side but others don’t?
|
Everyone here is talking about properties of water cohesion and viscosity, but OP specifically asked about why certain **containers** pour well while others don't.
That has to do with the type of spout, or the way the glass/plastic is shaped at the top of the container. You generally need a very sharp edge, or a very crisp curve at the end of the spout. The material of the spout also matters, and you tend to want surfaces that your liquid doesn't stick to as easily. If it's just a smooth rounded top, especially of glass, water will happily stick to the gentle flow over the curve and drip right down the sides of the glass rather than slide off the edge for a smooth pour. Sharper edges don't allow this, water can't stick to it and it just pours right off the end.
The thing with your typical glass drinking glasses, is they generally have very smooth edges because that feels gentler on our mouths, rather than the more geometrically sharp edges you'd see on something like a plastic milk jug. This is why trying to pour water slowly out of a drinking glass causes the water to disastrously pour down the sides, while pouring the same liquid out of a plastic bottle is successful. The drinking glass has soft rounded edges on the top for a more comfortable feel on your lips, while the bottle has sharper curved edges for pouring.
The only other variable is speed at which you pour, a faster pour gives the fluid more energy and forces it to fly off the edge and not drip. That's why if you really have to pour water of a drinking glass, you have to pour it quickly if you want to avoid a mess.
|
9cc3c6c0-3183-4b5f-8f7d-dc57e7f9ed72
|
bstimu
|
how do air conditioners work?
|
An air conditioner is simply a refrigerator that cools the air in general, instead of the inside of a box.
Refrigrators work by squeezing a gas, which makes it hot, letting it cool down inside pipes that are outside, then allowing it to expand, which makes it cool, and letting the gas warm up again in pipes inside. This pulls heat from inside your home and moves it to the outside.
The way that gasses heat up as they are squashed, or compressed, and cool down as they are released, is just a feature of how gasses work.
|
0e88c3fd-2eb9-42f9-8001-ede80c0158d8
|
bstjpx
|
Why are vietnam veterans praised so much in America?
|
Mainly , and this is my opinion/take on it, because a majority (FC?) of the military was drafted and there were *lots* of protests against the Vietnam war and how we shouldn’t have been there. It was a horribly gruesome war, and the veterans of it deserve the praise because of what they were forced to endure meaninglessly.
|
f9e2d7f6-20ce-414b-b677-d10914cb806c
|
bsty1k
|
What is the point of your anus having so many nerve endings? Why is it so sensitive?
|
Some believe that defecating feels good because our bodies often reward us for necessary functions, such as eating, defecating, urinating and procreating. In other words, we have nerves down there so that it feels good when we poop, so that we enjoy pooping, so that we don't hold the poop in and mess up our bodies.
|
90a03374-9c4e-49ec-9185-72f84f1dde70
|
bstygd
|
What causes wind?
|
Air gets more hot at some places than other. The places where it gets hot, the air rises(since hot air is lighter than cold air).
Air from surrounding areas flow in to fill the place where the hot air has risen, causing wind.
Why does air get hotter at some places?
Due to difference in latitude, land type, vegetation, altitude, etc.
|
8726c4a8-111e-4e9d-b42f-ec7689008e23
|
bsuer2
|
what do anti-histamines do to the body that reduces allergies?
|
It's in the name: they are *anti* (against) *histamine* (a signal your body uses to activate your immune system).
Whenever you're injured or your body senses an attack, the cells around the affected area release histamine. The histamine tells that part of the body to do things like dilate the blood vessels to cause inflammation and, if near the face, to produce more mucus and tears. These are normally good responses, because they help your body fight off harmful pathogens. Allergies happen when histamine is released in response to harmless stimuli like pollen, and the histamine response is overly aggressive.
Anti-histamines block that response in a number of ways. Mostly they fit into the receptors that the histamine normally fits in. When the histamine gets into the receptor, it activates the other chemical signals that cause the symptoms. The anti-histamine gets into that receptor without activating it, blocking the histamine from being able to turn it on. Sometimes the anti-histamine *do* turn on the receptor, but in the opposite way so it tries to turn *down* the immune response. So the stimulus still happens, the pollen is still in your nose and some of your immune cells are freaking out about it, but their signals never get the chance to activate all the rest of your immune response.
Different drugs affect different histamine receptors (there are several) and some just block the receptor (receptor agonists) or turn it the opposite direction of histamine (inverse agonists). As a side-effect, histamine is a neurotransmitter that gets used for a number of things, including sleep-wake regulation. Histamines normally wake you up. So an inverse agonist anti-histamine, which does the opposite to the receptors that histamine would do, makes you tired.
|
17d641d8-9e11-414e-808d-018be66863cf
|
bsuu0p
|
What makes up the part of food that's neither carbs, protein, fibre, nor fats?
|
Water. Most living things are mostly water. Lettuce is 96% water. meat is like 75% water. Even dry fruit like like 20% water. Most stuff you eat is wet enough you can squeeze it and make juice come out.
|
73bb62cf-cf26-4ad1-811d-d0bb5422ad81
|
bsv6dh
|
how does each study model work and why are some better than others? Aka Cohort, meta analyse, epidemiological, etc
|
Asking why one is better than another is like asking why a ruler is better than a measuring cup. Each study model gathers a specific kind of information at the expense of other kinds. A meta-analysis is going to give you a bird's eye view of your subject by looking only at the clean statistical data gathered by others, but you won't easily see what variables impact the findings. A case study will give you a very detailed look at your subject in one scenario, and you'll get great information on potential variables that impact your findings, but you'll also need to weed out variables specific to the case. A cohort study helps you with the weeding out, but it's more expensive in time and resources, so you usually need to justify the design with a case study first.
|
5cacda0b-31e9-4d51-8d8b-9f90e7d92045
|
bsvjdt
|
Why is it common to pronounce some latin names like Caesar and Cicero with a soft C instead of a hard K (the traditional latin pronunciation), but not names like Cornelius and Caius?
|
I mean, in Classical Latin, it really is pronounced "Kae-sar" and "Kae-sero," but English speakers are terrible about not butchering names.
Plus, it's how Ecclesiastical Latin pronounces some of them, because it's more related to Italian.
|
57b28733-cb38-4a40-9492-57ae13170fdd
|
bsvjrp
|
Why do people lease cars? It seems like such a waste of money to me.
|
For some people, like sales people who travel a lot, need a new car every 2 or 3 years and can take a business deduction, it can make sense.
For anyone else, it's the appeal of the nice car for a lower monthly payment. It's not the frugal choice, but people can be taken in by the hype, or they just really place a lot of value on driving a nicer car than they can afford to buy outright.
|
1c287b3b-dae2-4ba0-83c1-4a28818fb818
|
bsvpz8
|
Why does overcooking chicken breast make it rubbery, while overcooking other parts like the thighs make it tender?
|
Breasts and thighs cook at different rates. If you cook them the same amount of time, you are likely overcooking the breast and perfectly cooking the thighs.
Also, tenderness is a combo of the structure of the meat and moisture level. Chicken breast has almost no fat or connective tissue. When you cook it, you are getting rid of water and killing microbes. Too much water gone makes the meat dry and chewy.
Personally, I don't like chicken breast. I always go for thighs.
|
8c576d6d-a025-45cf-84c1-508d81a44348
|
bsvrli
|
How does sunburn/tanning happen and how does the SPF number in sunscreen affect that?
|
UV light from the sun is able to alter nucleotides (the letters) in your DNA, meaning the code is altered (mutated) and no longer means the same thing = miscoded proteins. Therefore UV light can be called mutagenic, aka bad. Our bodies have developed mechanisms to protect our cells and the DNA inside from UV-induced mutations by producing a molecule called melanin. Melanin absorbs UV light (and also some visible light) which makes our skin look darker - a tan. More UV exposure triggers more melanin production, hence more tanning.
& #x200B;
BUT that doesn't mean exposure to as much UV as possible is good. Melanin production is ramped up in response to DNA damage, it doesn't magically know the damaging UV is there beforehand, so we limit our UV exposure with sunscreen!
Sunscreen works by absorbing UV light, basically artificial melanin. The SPF number corresponds to the amount of UV that is absorbed. The lower the number, the less UV is absorbed, which is better for darker skin types and those who have been in the sun for a long period of time (few days/weeks). Higher SPF is crucial for those with very light skin (shoutout to all you gingers in the place) and if you haven't been in the sun for a while, to let your melanin production catch up.
& #x200B;
hope this helped!
|
66cc6b1e-46c3-48c8-ae57-619943002967
|
bsvvil
|
what actually happens when a molecule activates a receptor vs when an inhibitor molecule just blocks it?
|
Think of the molecule as a key and the receptor as a lock. The "real" key will always be able to open the lock as intended. However, there are some keys that coincidentally have a similar shape to the "real" key, but not similar enough to open the lock. So when you try to open the lock with the similar key, instead of opening the lock, it gets jammed and it gets stuck. The lock is still locked while the key is stuck, which is a metaphor for how the inhibitor just gets stuck in the receptor without causing a biological effect.
|
3582785f-22d9-4df2-bc66-0da57253142a
|
bsvxs6
|
Why is radiation so dangerous and how does it cause so much harm?
|
Radiation itself, as a whole, is not dangerous... Certain types of radiation like ionizing radiation can be dangerous by changing your DNA. All radiation (ionizing and non-ionizing) can be dangerous if they are intense enough to cause burns by imparting enough energy to heat things up. However for the most part radiation is not dangerous.
Radiation, or rather electromagnetic radiation are simply just electromagnetic waves like microwaves, radio waves, infrared waves, visible light, etc. However some of these wavelengths (dubbed xrays and gamma rays and some frequencies of ultraviolet waves) have the potential to ionize (rip electrons off) of the sugar molecules that make the "rungs" of your DNA (as DNA is kind of visualized as a double-helix ladder).
When the "rung" is ionized it can break apart and form malform bonds with other broken rungs and becomes a jumble of random DNA bonds. So when the mechanisms that fix DNA approach this they will see this jumble and work to fix it, it's this fixing of the jumble that can cause mutations in the DNA by changing the order which the DNA was in which can cause malformed proteins that can disrupt normal cell cycles and cause cancer.
The second way that radiation can be used to cause harm is through heat transfer. It takes a lot depending on what wavelength (the shorter the wavelength the more energy it imparts as the more energy it has). This will explain why exposure to too much radiation can cause burns and effectively how microwaves (which are non-ionizing) can safely cook food.
Now we can't talk about radiation without talking about alpha and beta particles. Alpha particles are really heavy and positive particles released during radioactive decay of unstable nuclei (atoms... For instance uranium will release alpha particles when it decays). An alpha particle has 2 protons and 2 neutrons, in other words it's an ionized helium atom. This is dangerous because it has the potential to rip electrons off of other atoms to take them for itself, however they don't travel very far in air (a few centimeters) due to a number of reasons and unless you are really close and breathing them in they post very little risk. The biggest risk of alpha particles is if you ingest something or breath in the dust of something like radioactive iodine which will release alpha particles into your body which it can then ionize particles in your body and cause chaos. After alpha decay (when an atome ejects the positive helium nuclei) the original atom will restructure itself which releases a large amount of energy (relatively speaking) in the form of a gamma radiation.
Beta particles on the other hand are a little different. First I will explain the decay, beta decay is when a neutron spontaneously turns into a proton and an electron, charge and mass are conserved. The proton remains within the atom, the electron gets shot out of the atom with extremely high amounts of energy. This electron has the capability of ripping electrons off of other atoms (ionizing) by giving energy from itself to the other atom. I had read somewhere that a lot of beta particles are capable of ionizing up to 3 other electrons (alpha particles can do 1-2 ionization before they are neutralized) and can travel a lot further through air. Beta particles are also capable of penetration skin to some degree. After an atom goes through beta decay it will restructure itself releasing energy in the form of gamma radiation.
There are other types of decay like neutron emission and even more rarely proton emission but I think you get the general idea. An atom changes its internal structure by either ejecting something or having something change and then the atom restructures itself to become as stable as possible (the whole reason for radioactive decay is because the atom is unstable) and energy is released.
[radioactive decay](_URL_1_)
[how UV causes cancer, by Veritasium](_URL_0_)
|
653ee0a9-886d-4a7b-b1b9-c07c7e50332a
|
bsvy8d
|
What are the benefits of leasing a car over buying one?
|
None. Buy a used car... It will save you so much money. Also buying used doesn't mean your buying junk. You can buy used cars from a dealership or private party with less than 10,000 miles easily, and save thousands of dollars.
|
75afd3e6-5de8-43bb-957f-8bf79ab5d439
|
bsvzaw
|
Why do people micromanage their investments if S & P500 beats most managed funds in the long term?
|
Actual hedge fund portfolio manager (although I work with debt, not stocks): Its important to understand what you're thinking about here.
First, there's nothing special about the SP500 - its just a list of stocks that are assembled by Standard & Poors. The rationale is this list comprises the 'biggest and best' of the US, but the people at S & P are picking that list. And the weighting can be fairly arbitrary and its a known flaw that it *heavily* favors certain market caps, sectors and industries. Lastly, (and this is more advanced) but the dollar-risk weighting isn't that great for the SP500; when you just buy the SPY ETF (the fund that tracks the SP500), you aren't getting great compensation for the risk you are taking. This is the single biggest metric for professional investors.
So the take away is this: *The SP500 is largely just an unremarkable list of stocks that pays an average return.*
Second, professional investors have *vastly* different metrics than the people on r/wallstreetbets. My bonus is determined not by outright performance, but my 'return per unit of risk'. This is a *huge* simplification, but let's just say that 'risk' is volatility. If I just buy the SPY, I get 100% of the return, but I also bear 100% of the risk. That sucks. My goal is to capture about 80% of the SPY return, but only take about 30%-40% of the risk by using hyper-complicated hedging strategies.
It makes me cringe to no end when I read an article about 'hedge funds continue to lag the major indexes' b/c it means the author has no clue about the topic at hand. A great year for me is called an '80/40' where I captured 80% of the return, but only saw 40% of the risk. But think about it - *I'll never beat the index b/c that's not my goal!!!* If I captured 100% of the index return, my Chief Risk Officer is going to 'dial me down', which means that he's going to force me to pull back trades - this is a *HUGE* 'no no' at my level.
So the second take away is this: *Professional investors are not trying to beat the SP500 either!!* We are trying to beat the index on a 'return per unit risk' basis which is very different.
|
6ac10659-bae0-4d19-8b7c-2fb75bb4e142
|
bsw527
|
What is NBA Cap Room ad how does it affect signing players and contracts?
|
Professional sports are an entertainment thing. So if one team that had the most money could just hire everyone good and win forever with no issues the game would be dumb to watch pretty quick. So there is rules about the total amount a team can spend on players.
Cap room is the amount they didn't spend. Like if there was a limit of 100 million and they only spent 98 million they'd have 2 million in cap room. There is a lot of rules about it because people try to pull tomfoolery to subvert it. And they want to make sure the sport doesn't just become too much a thing where the richest team wins every game and the poorest team loses every game forever and ever and every good player just ends up with whoever pays the most.
|
b160a048-c867-43c8-9fcd-59547fb7c31d
|
bsw6gt
|
How does electrocution in water work?
|
Let's understand principles first.
1. The maximum current flow will occur along the path of least resistance.
That is it.
Now consider your first scenario.
In bathtub, when live wire(the one that is at high alternating voltage) touches the water, it will find the path of least resistance. This could be a path in water to say the drain pipe which is solid metal and is connected to your plumbing system which is usually at ground potential. Now this could provide a path of least resistance and you will not be harmed. However, say you or your limbs provide a path of least resistance, the current flow through your body will kill you because this amount of current actually generates a lot of heat which reduces your body's resistance and allows more current to flow to cook you 'ripe'. The case in swimming pool and bath tub is same except that the chances of current flowing to ground are high due to multiple holes dug in it(for electrical and plumbing outlets). The video in the following link will help you understand.
_URL_1_
How does it kill?
Well the current basically wreaks havoc on your nervous system. Consider that you pass such high current through a wire that is not designed to tolerate such high current. This causes burns too since your body heats up. Also, major risk of electrocution is fibrillation. Consider, your heart like a drum beating at a constant rate and some powerful elephant grabs the drummer by its trunk and bangs him on the drum black and blue with its own random rhythm. Surely, your heart is not working as it should and this loss of rhythm is called fibrillation. This is what kills people in majority of scenarios due to electrocution.
Now let's see how our friends in the ocean are doing.
When the lightning strikes ocean, the huge current flowing through atmosphere to the ocean which then discharges via path of least resistance. Now for current to harm fishes it actually has to travel below the surface where fishes usually are.
Also majority of the current flows along the surface of water. ( I will try to get back to you with
ELI5 version of this).
Hence the current harms only certain fish within the area.
The following link discusses the probability of harm.
_URL_0_
|
6de890f9-534e-40ab-a174-6afa9bcaa25d
|
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