Recent comments in /f/explainlikeimfive
Dalemaunder t1_jabmer4 wrote
Reply to comment by Revenge_of_the_User in ELI5: Why is it that when fertilizers make their way into waterways, all the oxygen disappears, killing the fish? by Psychological-Dog994
Damn, nature. You scary.
jleenyy t1_jabmbtf wrote
Reply to ELI5 - What are calls/puts in stock trading, and how are returns calculated when they are executed? by burman07
A call option is a bet that a stock will go above the "strike price" by a certain date, called the expiry date. A put option is a bet that a stock will go below the "strike price" by the expiry date.
If the expiry date arrives and the stock hasn't done this, the option expires worthless and you won't get anything back. If the stock has done this, then your option is worth something, based on a bunch of calculations (Greeks) which I won't go into because it's way too advanced.
However, you are free to sell the options before the expiry date, and the value of the options at the time you want to sell is calculated based on the Greeks (Black Scholes Model).
There are plenty of resources available on YouTube and Investopedia.
5kyl3r t1_jabmafi wrote
Reply to ELI5: What is a "naturally aspirated" engine? Is it always desirable? Are there "artificially aspirated" engines ? by Gaboik
wall of text, be warned lol:
ICE engines (internal combustion engine, or ELI5: inside explosions engine). they mix air and gasoline to make explosions. explosions are just gas expanding REALLY quickly. like when you pop a balloon. (air is a gas too). we use the expanding gas to create motion that moves our cars. engineers will probably comment that it's actually burning the air and gasoline, but this is ELI5, so i'll stick with explosions, as they're cooler and i think easier to picture how this works as explosions than "burning"
you have to mix a very specific amount of air and gasoline together to make the strongest explosion. if i remember correctly, for every 1 shotglass of gasoline, you need to mix 14 shotglasses of air. that makes the perfect mixture that will give you the most power while keeping the engine safe. if you have too much air, it might make a little more power, but it will get really hot and the engine will eventually die. if you have too much fuel, it will make less power and make lots of smoke and will gunk up your engine and eventually cause problems. that's why this 14:1 mixture is important
if you've ever used one of those swimming pool water cannons, (or a medical syringe), you pull back on the piston, and that pulls water into it. in the case of the engine, the piston moves downwards and when it does, it pulls fresh air in. so you add enough fuel to make the perfect 14:1 mixture of air:gasoline, and you get an explosion. (the spark plug makes a spark the lights the gasoline and air mixture that creates the explosion) but that's the maximum power you can make, because gasoline has a specific amount of energy in it. to make more power, you need a bigger explosion. to get a bigger explosion, you need more gasoline. but remember the air and gasoline mixture thing? if you add twice as much gasoline, the engine will still only be able to pull in the same amount of air, so you'll be at 7:1 air to gasoline. that's way outside the 14:1 you're trying to get and it will not work. this is basically a naturally aspirated engine. aspiration is just a fancy word for breathing. it naturally breathes in fresh air when the pistons are moving downwards.
but with forced induction, or forced breathing, you can get more power. you might already be guessing how that works. we use either a turbocharger OR supercharger to force more air into the engine than it can naturally pull in. (that's where the naturally aspirated name comes from) the more air we force into the engine, the more fuel we can mix in to make more power. (bigger explosions). the important thing is that the perfect mixture of air and gasoline is kept. the engine's computer measures the air coming into the engine so it knows exactly how much fuel to squirt in to get the perfect 14:1 mixture.
how do they work? simply put, they're air compressors. like the one you air up your car or bicycle tires with. or party balloons. or inflatable mattress or basketball. there are many types of compressors of course, but that should maybe make your brain make some connections to things like tires and balloons. those have air forced into them too, and for that, we need a compressor. superchargers are spun by the engine with a belt. the engine spins, a pulley turns a belt, and the belt is connected to another pulley on the supercharger, which spins the supercharger, and that forces air into the engine. the faster the engine spins, the faster the supercharger spins, and the more air is forced into the engine. that lets your car's computer add more fuel to keep the mixture at 14:1, but since you're adding more gasoline, you're going to make more power
a turbocharger is a compressor, but it also has a second turbine. one is for exhaust, and one is for the clean fresh air that it's compressing. instead of the engine spinning it like the supercharger with a physical connection (a belt), turbos use exhaust gases coming out of the engine to spin the turbine. it's like if you blow on a pinwheel, they spin. same here. but that exhaust turbine has its own housing (case/compartment/section/house, whatever you wanna call it, the exhaust turbine and compressor turbine have their own separated compartments). the other turbine is the compressor, and that does what the supercharger does. the exhaust turbine and the compressor turbine are connected with a shaft, but the case is separated so the exhaust gas stays on the exhaust side and the clean air stays on the clean side, and they can't mix, but the motion from the exhaust turbine spins the compressor from that shaft that goes between the exhaust/compressor sides. since it's not directly connected to your engine with a belt, there's a delay. when you start to accelerate, there isn't much exhaust gas coming out, so it takes a second for the turbo to "spool up". you're basically just waiting for it to start spinning fast enough to compress air to force into your engine. that's the turbo lag. a supercharger spins the supercharger directly from the engine with a belt, so it's instant. just like a naturally aspirated engine. both those engines make the maximum potential power for any RPM immediately when you push the gas pedal. turbo engines do not. not until they're making enough boost pressure from the turbo. bigger turbos can make a lot more maximum boost (boost is just slang for pressure) but bigger turbos have more turbo lag. smaller turbos spool up much faster (so less lag), but they'll have a lower maximum boost pressure possible, which limits max power. most modern turbos in normal passenger cars like a honda accord 2.0 turbo, will have a fairly small turbo. they use it for efficiency, so they don't need a huge turbo. those cars are designed to get good gas mileage. turbos help with this because you can use a smaller lighter engine but still get enough power thanks to the turbo. if you've driven a modern car, even a passenger car like an accord that has a turbo, you'll notice they have more power taking off from stoplights. that's because once the turbo is spooled up, the engine can make good power even a lower rpm's. the supercharger and naturally aspirated engines usually make more power in higher rpm's. (superchargers can be the exception, it depends on the size of the pulley, you can adjust how much boost pressure your supercharger gives you by adjusting the size of the pulleys, just like shift gears on a bicycle that has the ability to shift gears.)
oh, and maybe you're curious, so i can add nitrous to this explanation. nitrous itself isn't adding energy to the explosions. that's why the fast and furious nitrous explosion was just silly. the part of the air that is actually important is oxygen. that's the important part of the air that we need to make the explosions with the gasoline. nitrous is an oxidizer. you've possibly heard that word used when people are talking about rockets. as you might have noticed from the name, oxidizer looks similar to the word oxygen. that's because they're related! oxidizers add oxygen to reactions. instead of needing a supercharger or turbo to force more air into the engine, you can use an oxidizer like nitrous to add the oxygen we need. that lets you add more fuel without needing to force more air into the engine, since the oxygen is the part of the air we need, and the nitrious is giving us that. so for most (safer) nitrous kits, they know how much more oxygen your engine will get, so they usually add extra fuel to keep the mixture of gasoline to oxygen perfect. (it's not 14:1, since that's for air and gasoline, and here with nitrous, we're talking about only oxygen instead of extra air, so the ratio will be different, but you can google "oxygen to gasoline stoichiometry" if you're curious about it)
that's probably TL;DR, but if you're interested in this stuff, maybe not. this is ELI5, so i greatly simplified a lot of this stuff, but it should be enough to make you understand the basics of these things, which will hopefully spark more curious questions so you can go learn even more. cheers
qwerter96 t1_jabm7lu wrote
Reply to comment by burman07 in ELI5 - What are calls/puts in stock trading, and how are returns calculated when they are executed? by burman07
The greeks is the short answer: https://www.investopedia.com/trading/using-the-greeks-to-understand-options/ if you have a more concrete question happy to delve deeper
MakesMyHeadHurt t1_jabltlg wrote
Reply to comment by Gaboik in ELI5: What is a "naturally aspirated" engine? Is it always desirable? Are there "artificially aspirated" engines ? by Gaboik
It's because the turbo forces air in at a higher pressure. The extra pressure puts extra strain on various parts and seals.
Edit: Also it's more parts, so that means more parts that could fail.
burman07 OP t1_jablohl wrote
Reply to comment by TheBeatdigger in ELI5 - What are calls/puts in stock trading, and how are returns calculated when they are executed? by burman07
Gotcha, what factors decide the ROI percentages?
Ojisan1 t1_jabll0e wrote
Reply to comment by iaintlyon in ELI5: What's at the edge of the universe? by roohooreddit
That’s where it gets complicated. We don’t know because we can only observe 13.7 billion light years in every direction. So what we see is a sphere with us at the center. But there are some other things that suggest that the universe is a hypersphere or a hypertoroid.
It’s not possible for us to picture these objects except by approximation, or with math, or with analogies. But a short explanation: A sphere is a circle extended into an additional dimension. You can visualize that. A hypersphere is a sphere extended into an additional dimension. Can’t visualize it, but that’s what it means.
A torus is a donut shape, so a hypertoroid is a donut extended into an additional dimension.
There are videos about hypercubes, and hyperspheres, which attempt to help picture what it’s like, but because our minds operate in 3 dimensions, it’s not capable of truly comprehending these 4 dimensional objects.
Thugmeet t1_jabl5sq wrote
Reply to comment by SirCarboy in ELI5: What is a "naturally aspirated" engine? Is it always desirable? Are there "artificially aspirated" engines ? by Gaboik
With new turbo technology that delay has become a lot shorter.
TheBeatdigger t1_jabl4p2 wrote
Reply to ELI5 - What are calls/puts in stock trading, and how are returns calculated when they are executed? by burman07
Plenty of YouTube vids about it. You’re basically betting on whether a stock (the underlying) will go up (call) or down (put) by a certain date (expiration date).
Successful_Box_1007 t1_jabl4ew wrote
Reply to comment by TheSkiGeek in Eli5: How did people know how long a year was in olden times? by Slokkkk
I see. Thanks!
jet-setting t1_jabl0z5 wrote
Reply to comment by fiatfighter in Eli5: How did people know how long a year was in olden times? by Slokkkk
Put stick in ground. Look at shadow.
TheSkiGeek t1_jabkzg4 wrote
Reply to comment by annomandaris in Eli5: How did people know how long a year was in olden times? by Slokkkk
Hard to tell when it’s exactly noon.
More reliable to mark where on the horizon the sun sets/rises each day. When the movement of that point stops and reverses, that’s either the winter or summer solstice.
p_m_a_t_t t1_jabkoi0 wrote
Reply to comment by Successful_Box_1007 in Eli5: How did people know how long a year was in olden times? by Slokkkk
Just because a tool is 'rudimentary' doesn't mean it doesn't work!
TheSkiGeek t1_jabknby wrote
Reply to comment by Successful_Box_1007 in Eli5: How did people know how long a year was in olden times? by Slokkkk
Yeah, but you only need to get close. It’s okay if you’re off by a day or two if all you’re using it for is to decide when to plant and harvest crops.
If you’re staying in one place for a while you can set up more permanent solutions. Structures like Stonehenge have notches and openings that line up with the sun position in different seasons, so you can tell exactly which day is the solstice or equinox (or whatever days are important to you).
Taibok t1_jabk81k wrote
Reply to comment by [deleted] in ELI5: Why is it that when fertilizers make their way into waterways, all the oxygen disappears, killing the fish? by Psychological-Dog994
Photosynthesis requires oxygen?
iaintlyon t1_jabk6ga wrote
Reply to comment by Ojisan1 in ELI5: What's at the edge of the universe? by roohooreddit
Hm. So is there a hypothetical shape of the universe?
Successful_Box_1007 t1_jabk5wa wrote
Reply to comment by PlanetLandon in Eli5: How did people know how long a year was in olden times? by Slokkkk
True but isn’ the variation super small all things being equal (including time of day you measure)? With their rudimentary tools it must have been tough.
FunnyHighway9575 t1_jabk3vr wrote
Reply to ELI5 How do banks work? by RussianPremier
They loan your money to other people and charge interest to get the loan. So if you keep your money in a savings account, the bank gives you 0.01% interest but can turn around and give your money to many other people and charge let's say 5% interest or more to the ones receiving it.
They also charge fees like maintenance fees, annual fees, membership fees, etc
DoomGoober t1_jabjtzs wrote
Reply to comment by Caucasiafro in ELI5: If the tongue can only taste five basic flavors (sweet, sour, bitter, salty, umami), why isn't it possible to create any flavor by mixing those five together in precise combinations? by bokbokboi
Add to this that the brain changes the "flavor" of food based on what it thinks the food is.
There have been experiments showing people report different flavors of food/drink based on the color of the bowl/cup the food is served in.
Obvious the color of the container doesn't actually change the food flavor but the brain takes it into account.
Aefyns t1_jabjtz0 wrote
Reply to ELI5 How do banks work? by RussianPremier
You deposit money.
They loan your money out.
The interest is their profit.
The government insures banks via FDIC. Lots of regulations on how to do all this but essentially this is the gist.
TL;DR Banks loan out your money to other people. Other people pay the bank to use your money.
[deleted] t1_jabjj3n wrote
Reply to ELI5 How do banks work? by RussianPremier
[removed]
Barneyk t1_jabjez6 wrote
Reply to comment by Spiritual_Jaguar4685 in ELI5: Why is it that when fertilizers make their way into waterways, all the oxygen disappears, killing the fish? by Psychological-Dog994
>so the missing piece for you is the algae, they eat the food, they grow like crazy, they breathe up all the water-oxygen, everything else dies..
This is worded so badly.
Algae are plants that produce oxygen, they don't breathe it up.
oudeicrat t1_jabjdmv wrote
in addition to all the great comments here about the solar latitude I'd add that it doesn't take that much technology and knowledge to count each day/night cycle and realise the seasons and the star constellations (especially the zodiac) come back and repeat after you counted roughly 365
TheLuminary t1_jabj0t4 wrote
Reply to comment by johnnymacmax in ELI5: how does rendering a video game resolution above your monitor resolution make the picture more crisp? by ItsSnowingOutside
The game does.... But it uses these techniques to do it. That's why you have lots of antialiasing options, including super sampling.
Rendering higher resolution for your display, but turning anti aliasing off. Is just kind of manually doing what is built in
zmz2 t1_jabmgo2 wrote
Reply to comment by FunnyHighway9575 in ELI5 How do banks work? by RussianPremier
My checking account gives me 4% so your numbers are out of date. I pay no maintenance fees, annual fees, or membership fees. Maybe you just have a shitty bank