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general1465yesterday at 10:48 PM6 repliesview on HN

Well the issue is that a lot of people believe that space is cold. If you will ask Google/Gemini what is a temperature of space, it will tell you:

The average temperature of deep space is approximately -270.45°C or 2.73 Kelvin), which is just above absolute zero. This baseline temperature is set by the Cosmic Microwave Background (CMB) radiatio...

Which is absolute nonsense, because vacuum has no temperature.


Replies

jfengelyesterday at 11:38 PM

Vacuum does have a temperature; it has a blackbody temperature.

https://en.wikipedia.org/wiki/Black-body_radiation

It has nothing to do with the movements of atoms, but just with the spectrum of photons moving through it. It means that eventually, any object left in space will reach that temperature. But it will not necessarily do it quickly, which is what you need if you're trying to cool something that is emitting heat.

drowsspayesterday at 11:57 PM

That's not how it works. Two bodies are in thermal equilibrium if there's no heat transfer between them: that's the zeroth law of thermodynamics. If you're colder than 2.73K in deep space, you will absorb the heat from the Cosmic Microwave Background. If you're hotter, you will irradiate heat away. So it does have a temperature.

aqme28yesterday at 11:20 PM

Well it isn't a perfect vacuum and it does have a temperature. But temperature is only a part of the story, just like how you go hypothermic a lot faster in 50 degree water than in 50 degree air.

ZeroGravitasyesterday at 11:11 PM

I saw a news personality say that space is cold and that solves a big problem with datacenters as justification for why it made sense.

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emkoemkoyesterday at 11:22 PM

but if you did use thermometer in space it would eventual read 2.73 kelvin right? so whats the issue? and also for a space based server it would have to deal with the energy coming from the sun

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guluarteyesterday at 11:33 PM

I'm not a scientist but i am also sure it will be fucking hard to dissipate heat in a vacuum