Recent comments in /f/explainlikeimfive
ThepunfishersGun t1_jabiieu wrote
Reply to comment by TheRichTurner in ELI5: Why is it that when fertilizers make their way into waterways, all the oxygen disappears, killing the fish? by Psychological-Dog994
Henry's Law (I believe, been awhile since college/grad school) partial pressure of dissolved gas in liquid is proportional to partial pressure of undissolved gas. IIRC, it goes: p1/a1 = p2/a2 where one side of the equation describes gas dissolved at a given atmospheric pressure and the other side describes gas dissolved at a changed atmospheric pressure.
yono1986 t1_jabidg1 wrote
Reply to ELI5: Only the top layer of water freezes in a lake because this layer insulates the rest of the water but the water in a trough in a freezer freezes all the way through. Why? by gud_doggo
Depth and quantity of water. Relative to a trough or bucket, a lake is huge. If it's cold enough to freeze a lake down 18 inches, a 12-in tall bucket will freeze solid, while the 20 ft deep lake will not.
PlanetLandon t1_jabiddd wrote
Reply to comment by Successful_Box_1007 in Eli5: How did people know how long a year was in olden times? by Slokkkk
It doesn’t really take anything special. If you have eyes and something to write with you can keep track of where the sun rises every day.
yono1986 t1_jabhzg2 wrote
Boxing is scored by the 10 must system. In a typical round, a judge gives whoever they think won the round 10 points and the loser gets nine. If somebody gets knocked down, then it is generally 10-8 against them. Every once in a while you will have 10-7 rounds, but you have to be truly awful to get that score.
BurnOutBrighter6 t1_jabhxca wrote
Reply to comment by krisalyssa in ELI5: What is Radar Cross Section in stealth fighters? by ChaosRider37
Also my "10 square feet" number was made up, it's just an example of what a "radar cross section" of [x] square feet means. Modern stealth fighters could well have radar cross sections the size of a pidgeon, sub 1 square foot, I'm not sure what "tiny" is these days.
its-a-throw-away_ t1_jabhprs wrote
The short answer: uncertainty.
Depending on the nature if the universe's genesis, it is possible that parts of it exists beyond the light cone which defines the bounds of what we could possibly observe.
Ojisan1 t1_jabhmis wrote
It’s like asking the question what’s at the edge of the earth? The answer is more earth. Just because you can’t see over the horizon doesn’t mean that’s all there is.
Similar with the universe - we can only see as far as light can travel in the amount of time since the universe began, just under 14 billion years. That’s like the horizon. But if you were able to magically teleport to 14 billion light years away from here, you’d still be able to see 14 billion light years in every direction. Similar to how if you teleported to the horizon on earth, you’d still just see the same distance to the horizon in every direction.
It’s more complicated because we are 3 dimensional beings in a 3 dimensional space, versus being 3 dimensional beings looking at the 2 dimensional surface of a sphere. If we were 4 dimensional beings, we could look at the 3D universe from a vantage point that would make it just as obvious that there’s no edge as it’s obvious to you that there’s no edge of a globe. But we aren’t 4 dimensional beings so we have to use analogies to understand without using math.
The way to understand expansion is that everything is getting further away from everything else. No matter where you are, everything else that exists is all moving away from you.
krisalyssa t1_jabh9n8 wrote
Reply to comment by BurnOutBrighter6 in ELI5: What is Radar Cross Section in stealth fighters? by ChaosRider37
I don’t know that I’d call 10 square feet “tiny”, but it is a lot smaller than the spatial cross section of a stealth fighter along any axis.
yono1986 t1_jabh64w wrote
Reply to Eli5: When/How did the world realize that it wasn’t the same time everywhere? by Ice_Ice_Fetus
Before time zones, there was local time. Essentially, whenever the sun at its highest point in the sky is noon. This was particularly difficult for rail travel, because a town that is a few dozen miles away has a slightly different local time, and you can't set a train schedule unless everyone agrees what time is when. Trains also move fast enough that you can notice time zones. Horse and foot travel are too slow for this. The other big thing was the telegraph. With telegraphs, you can now communicate with people who are clearly experiencing a different time.
Mkwdr t1_jabh5kk wrote
With some of these questions you could say we have working assumptions rather than absolute knowledge. To have an edge there would , I think, have to something that wasn't universe but the universe seems like all the space/time there is.
Though we don't know for sure , there is some reason for thinking it might also be infinite in size. There is in edge in the sense of the limit of our ability to observe. The observable universe has for us increased in size as telescopes get better though you could say that its also a sort of illusion since the further we look , the further back in the universe's history we are seeing. We are seeing it as was. We can only see as far as light has had time to travel. The limit is called the cosmic horizon.
And we also have some reason to think its pretty much the same everywhere in general. Though some bits are clumping together the space between is increasing everwhere. At one point in the past it infected very fast , slowed down and is now accelerating again. But as far as we know whereever you were in the universe you would look out and observe something similar to another observer. If the universe continue expanding its possible that we could imagine one day an observer looks out and sees nothing because all the stars would be too far away for light to reach them.
Jamie_1318 t1_jabh4vp 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
The space in the nostral also seems to matter. That 'fresh rain smell' primarily consists of a compound called geosmin. It smells fresh and nice from outside, but injesting it tastes moldy.
https://www.youtube.com/watch?v=_8vHsY_QVHM
Caucasiafro t1_jabh4ei wrote
Reply to comment by valeyard89 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
McDowell's might be able to pull it off.
[deleted] t1_jabh1qn wrote
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apoeticturtle t1_jabgplj wrote
Reply to comment by RubyPorto in Eli5 Help, please my brain hurts. If there is an expanding ring of light from the big bang, what is outside it? by ExtremeQuality1682
There are many things in my life that I do have to decide if I am OK with, but thankfully not this one. I cannot even imagine "nothing" and having less than nothing (that which lies beyond our Universe's edge) is as mind-boggling as it is speculative. All the energy in our Universe may be just a tiny fraction of all the energy everywhere/when. It seems more likely, to me, that our Universe is a tiny part of something bigger. If not, what a waste of energy and time/space.
slimfaydey t1_jabgmbj 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
man, product placement is getting more and more scientific.
valeyard89 t1_jabgllo 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
What about the Big Mick? They don't have sesame seeds.
specialsymbol t1_jabglf3 wrote
They would poke a stick in the ground and trace the shadow at noon. When the shadow reaches a point that was already marked a year has passed.
Bsmit992 t1_jabgkuj wrote
Reply to comment by zeratul98 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
This blows my mind but makes perfect sense.
Bsmit992 t1_jabgi8b wrote
Reply to comment by FarmboyJustice 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
Sometimes it tastes better
nim_opet t1_jabged6 wrote
Reply to comment by Prinzka in ELI5: Why is skin considered an organ? by PapaMamaGoldilocks
“I don’t wear women’s clothes. I bought them. They are my clothes. I wear my clothes!”
Ishidan01 t1_jabg9c0 wrote
Radar works by transmitting and observing the reflections of radio waves. Which are electromagnetic waves not unlike visible light, except in a different frequency, so we can use a visible light metaphor.
Imagine you are in the middle of a vast open field, and it's the middle of the night: there is no ambient light. But you have been equipped with a powerful flashlight, which you can point in any direction you like. You are also equipped with a partner we'll call Sam. Sam will go where you point if you command him to, and he's a very fast runner, but it takes him a few second
There are five enemies out there. Their job is to tag you out, but they lose if Sam tags them first.
Assassin 1 is vastly obese and is wearing a cheap white shirt. You spot him easily and Sam tags him out: he has an immense cross section.
Assassin 2 is just as obese but is wearing all black. Your flashlight does not reflect off him as well, but as he is such a large and slow moving target you have no problem seeing him in time to send Sam after him. His physical cross section is the same but his visual cross section is far less.
Assassin 3 is very athletic- not as fast as Sam, but damn fast. Still didn't pay attention to his wardrobe, though: his white shirt gives him more than enough cross section for you to see him and Sam to run him down before he reaches you.
Assassin 4 is like 3 but wearing all black. You barely spot him in time.
Assassin 5 came prepared. He spent a lot of time, money, and effort to camouflage himself. He can't change his physical cross section, but visually, you can't detect him because none of the light from your flashlight is returning to the detector-your eyes- in a way you recognize as a meaningful object.
sylpher250 t1_jabg542 wrote
Reply to comment by captaincarot in ELI5: What is Radar Cross Section in stealth fighters? by ChaosRider37
"Sir, there's a small bird on the radar!"
"So?"
"It's flying at Mach 1, sir!"
Book_Sea t1_jabg3u5 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
Algae doesn’t breathe up all the water oxygen. They are plants. It is the decomposers who eat all these small creatures who use the oxygen.
[deleted] t1_jabg0fp wrote
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johnnymacmax t1_jabiptz wrote
Reply to comment by TheLuminary in ELI5: how does rendering a video game resolution above your monitor resolution make the picture more crisp? by ItsSnowingOutside
Why doesn’t the game itself say the pixel should be gray instead of black or white? If the game renders in vectors, I’m assuming it can average for a specific resolution.