For preserving the least toxic and most culturally relevant Tumblr heritage posts.
Here are some OCR tools to assist you in transcribing posts:
FOSS Android Recs per u/m_f@discuss.online: 1 , 2
Don't be mean. I promise to do my best to judge that fairly.
I've heard that basically everywhere you go in space you will die by overheating because your body can't radiate away the heat it generates. It's weird to think that you can die from literally being cooked alive in a vacuum with a temperature of 0 degrees (readers choice of units).
Temperature is one of the least intuitive things when really getting into the nitty gritty of it. One of my favorite things to prompt people with is to ask them what makes something twice as hot as something else?
Physics is wild, man.
Rather than reader's choice of units, it has to be Kelvin... 0F or 0C is warm in absolute terms.
AcKsHuLlY it could also be in rankine
I'm being pedantic as fuuuuuck because I've never actually seen it used in real life. For those that don't know, it's similar to Kelvin in that 0 is actually absolute zero, but the degree step sizes are the same as fahrenheit
Rankine is used in chemical engineering calcs because a lot of US chemical plants are built in US Customary units and it's a lot easier to calculate in Rankine and keep everything in that system than try to convert back and forth between K and F.
Thanks for the interesting info! I figured it was used somewhere, just hadn't seen it.
And reminded me of the unit I saw once that I hate the most. Kilofeet... Not kidding. Apparently used in telecommunications as a unit of length for spools of cable, probably for similar reasons of easier math but couldn't fully switch from the US standard.
Sure but all three are colder than body temp
Temperature is the average speed of atoms, in space, what atoms?
Space isn't cold. It just isn't any temperature
Right, so getting to that whole "temperature is a measure of average speed of atoms," what's the average speed of atoms in 100 degrees Celsius boiling water vs 100 degree celsius steam? Or for that matter any solid at any given temperature compared to any gas of the same temperature? See what I mean when I said not intuitive?
Also, even in a vacuum a thermometer will eventually settle on a temperature it'll just take longer to equalise.
Atoms move in a solid, they just vibrate, in a liquid and glass they fly around. Somewhat bonded to each other in a liquid. But the speed is the same for any given temperature.
In vacuum I think a thermometer will just go to absolute zero/boil off.
Earth's atmospheric temperature is not what this person is talking about. The temperature outside your door depends on the sun, sure, but it's due to Earth's atmosphere. Go 60 miles towards "up" and the temperature of space is not the 68 degrees it is on the ground.
I think OP is questioning the temperature of the vacuum of space near the Sun. It doesn't really work like that though.
You don't think a function of the temperature from the sun to the earth forms a continuous line? You think it's piecewise? It's continuous! Yeah it probably bottoms out to effectively zero pretty quick, but there's some distance from the sun that would be the right temperature. Sure, the other rays from the sun might not make it livable. Sure, it might be so narrow there's no way to effectively keep yourself in orbit there without getting sucked closer and burning up. Sure, it's a dumb thought experiment, but there's no way there isn't some point where it's comfortable.
Empty space is not like our atmosphere. Similar to sound not going through space, empty space is not a medium that can be heated. You can't heat nothing. Heat is excited atoms. You can't excite nothing.
The atmosphere does just "stop" either though. It also forms a gradient. There's not a magic barrier where the atmosphere is and isn't. It just gets gradually thinner and thinner. So in the same way there's a Goldilocks spot in the atmosphere where it's a comfortable temperature without being too cold, there must be another one near the sun.
Besides, heat radiation travels through a vacuum. If it didn't then the Earth wouldn't get heat from the sun at all.
It travels through the vacuum, but it doesn't heat the vacuum, there's nothing there to heat. The "Goldilocks spot in the atmosphere" is on the ground, that's why we live here.
When you're close enough to the sun it heats you enough, because at some point you're so close you'll burn up, and at some point you'll freeze, so there must be a point between them that's comfortable. (And yes that might involve spinning so you don't cook on one side and freeze on the other.)
I'm sorry, but there's so much wrong with what you said that I can't even begin to correct you.
The thing about temperature is that it's not instant. Radiation from the sun heats stuff up, and that heat is absorbed by whatever the radiation hits according to its reflectivity and shape, and then lost from conduction, convection, and radiation. The characteristics of what's being heated by the sun and the environment it's in are what determine how hot it gets.
Exactly, so there must be some environment between us and the sun that's comfortable.
To expand on the "doesn't work like that" part: In the vacuum of space there is no air to exchange warmth with your body, or your space suit. You might be comfy on the side of your body facing the sun (if you're at that distance where it provides the right amount of radiative heat) but the side facing away from the sun will get no heat, and therefore be cold. I imagine that would feel very weird... if you could feel it on your skin, without a space suit, without being ripped apart by the vacuum, of course.
Does anyone know whether this "uneven distribution of heat energy" is a problem for space suits or if that little bit of air inside is enough to distribute it?
But imagine the side facing the sun is comfortable. Then it keeps warming up. And it keeps warming up. And you try to cool down, but it doesn't cool, it just stays the same temperature or keeps warming up.
the uneven heating would likely feel like being next to a fireplace
What if we spin around like a spit roast so the heat gets evenly distributed?
How fast should we spin as well?
I wonder what it would do in relation to vertigo. I mean there's no gravity to affect the vestibular system, but there are strong visual cues.
Ah crap, I'm going to go down a "what happens when an astronaut spins" rabbit hole today, ain't I? I had shit to do, oh well
There are glacier fed lakes when i live. You can float in incredibly cold water and if you have just the right equilibrium you can half float in freezing cold water while half getting a nice sun bath. And it IS very weird.
One spot I camped at for many years had nice sandy area that was about 200 meters out into the lake before a drop off. As it was only about a meter deep it used to warm up the top foot or so of the water when it was fairly still and you could stick your arm down into the water and actually feel the temperature drop like there was a line underneath the water.
Was great place to camp before it got overwhelmed by mosquitos
A lot of nice places in the world that are a joy to be in until the mosquitoes show up. Do we have to have mosquitoes? Can't the world manage without them?
NASA EVA suits have liquid (water) cooling systems to avoid cooking the astronaut while outside the ISS.
I don't know how they actually work though. The only way to shed the heat is to radiate it away or to sink it into warming something else up.
Found this on Wikipedia:
In an independent space suit, the heat is ultimately transferred to a thin sheet of ice (formed by a separate feed water source). Due to the extremely low pressure in space, the heated ice sublimates directly to water vapor, which is then vented away from the suit.
The ice sublimator consists of sintered nickel plates with microscopic pores which are sized to permit the water to freeze in the plate without damaging it. When heat needs to be removed, the ice in the pores melts and the water passes through them to form a thin sheet which sublimates. When there is no need for heat to be removed, this water refreezes, sealing the plate. The rate of sublimation of the ice is directly proportional to the amount of heat needing to be removed, so the system is self-regulating and needs no moving parts. During EVA on the Moon, this system had an outlet gas temperature of 44 °F (7 °C),[1] As an example, during the Apollo 12 commander's first EVA (of 3 hrs, 44 minutes), 4.75 lb (2.15 kg) of feedwater were sublimated, and this dissipated 894.4 BTU/h (262.1 W).[2] The pores eventually get clogged through contamination and the plates need to be replaced.[3]
Though I think that's specifically for removing the astronaut's body heat.
What a great system. I wonder how the development of that worked. Did they theorize the necessity of a system like that or were the first space walkers quite unconfortable?
This uneven heat distribution confuses the brain and is perceived as pain. Veritasium (or maybe vsauce) did a video on it. Putting frozen and warm hotdog against the skin.
Why can some objects exist in space without getting ripped apart like a human would. Is that what actually happens to a human anyways?
Ever seen a picture of a blobfish in it's deep ocean habitat vs when it is at the surface? It's body is adapted to the extreme pressure of the deep sea, and when that pressure is no longer there, the forces keeping it's shape are no longer present and thus every bit of it expands. That's what would happen to us in the vacuum of space albeit on a lesser scale. Also, we're like 70% water which boils in a vacuum.
As I understand it, this in fact will not happen. Our circulatory system is a closed loop and strong enough to not expand into vacuum. The water inside our body is kept close to usual pressure by our skin, blood vessels etc.
The main immediate danger in space without a spacesuit would be holding your breath. Your lungs are not built to withstand a whole atmosphere of pressure from the inside, and will get damaged if you hold your breath.
Of course if you don't, you'll have another problem.
Thanks for the clarification. I knew the whole lungs problem and that was really what I had in mind but just kind of assumed there'd be similar dangers to other bodily functions but I see that's not the case.
I do believe the water would still be an issue for your eyes and maybe even mouth but good to know you wouldn't immediately have blood literally boiling in your veins.
Space has no temperature. Space is a vacuum. Temperature needs things to jiggle.
The average temperature of the universe today is approximately 2.73 K (−270.42 °C; −454.76 °F), based on measurements of cosmic microwave background radiation.
https://en.wikipedia.org/wiki/Absolute_zero
Cited from https://www.abc.net.au/science/articles/2003/09/25/947116.htm
That's purely academic. IRL what actually matters is “how big and reflective is the thing you're in”.
You'd get real hot real fast in a matte black space suit.
Wonder how they calculated the "average" temperature. Was it weighted by mass or by volume?
Doesn't matter, it's just the eventual temperature of a black body kept in deep space
Only mass-weighting really makes sense here imo
Wouldn't that be just star and not star?
But a thing in space is not a vacuum and is subject to heating via solar radiation