this post was submitted on 10 Feb 2026
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Don't be mean. I promise to do my best to judge that fairly.
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I'm not a scientist, but I'm pretty sure temperature is the energy given to the molecules in the air by the radiation from the sun. Since there is no air in space to excite, it's just really cold until it's not.
The photons would directly excite the molecules in your body.
Which is why space suits are white. If they were darker, you‘d get cooked on a space walk. In a vacuum, the sunlight can heat you up but it’s much harder to radiate heat away.
Physics sure is exciting!
so hot right now
There's convective and radiative heat, while the first one needs some medium to transmit energy (air...), the second one simply beams it onto you
3 mechanisms for heat transfer: conduction (heat moves from one bit of matter to another when they are touching), convection (in a fluid, hot matter move about), and radiation (pure heat, only form that goes through a vacuum, this is just like lower frequency light that we can't see).
Thanks, I thought conduction was under convection, so to say
You just clarified the part where I said, "It doesn't really work like that though." I appreciate you, honey buns.
Temperature is how much movement there is at the molecular or atomic level(depending on how you are measuring.
There is a lower limit, but no upper limit on how much heat can be measured.
This is the basis of the Kelvin scale and starts at absolute zero or the temperature at which all movement (energy) stops
Air is a medium. Flowing air is a decent heat exchanger, still air is bad at it
Okay, thank you. I’m not a very smart man, and had always wondered how planets can be heated by the sun but not space itself. It never occurred to me it’s because of the vacuum of space that keeps it cold.
Gotta have stuff to be heated. Nothing can't be heated. But the energy that heats stuff can still pass through the space where the nothing is.