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this post was submitted on 02 Jul 2026
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My new supervisor, the day I met him, was talking about how space data centers are a great idea ("because it's so cold up there!") and will be amazing when they're online. That's the moment I realized he was breathtakingly stupid. He may not believe in thermodynamics, but thermodynamics believes in him.
I guess I shouldn't have expected much given that he has a degree in finance and has worked in consulting for 10 years.
AI as a cultural phenomenon has been truly exceptional at revealing the extent to which the privileged are just literally mouth breathing thumb sucking mental invalids.
We should be laughing in their faces, when they say shit this stupid. We should be pointing out that they must have failed highschool physics, mocking them, to their faces, with a little bit of accidental spittle to drive it home.
We literally have to shame these fucking morons or they will destroy human civilization.
I love it when they bring up the dangers of AGI. Dude, what about the dangers right now? Cognitive offloading, psychosis, environmental damage, financial bubble, mass layoffs (I know it's mostly a pretense for that one)...
Yeah, maybe at some point it'll be capable to destroy us, but right now it looks like we're going to do that before it'll get there.
How does thermodynamics make this a bad idea? Is it because the heat generated can't escape?
Yeah. The only way to cool things in space is to radiate it away with fins, or the more destructive approach of jettisoning material.
How do the fins help if there's no hot material being jettisoned? Are we assuming there is some atmosphere that will absorb the heat through (I'm guessing) convection?
Radiation is the part you are missing. The three ways of dissipating heat are: conduction, convection, and radiation which is what the "fins" do.
Doesn't it work out to something like a full kilometer of the things in order for it to work? The idea is pure madness.
Oh lord yes. Its why its stupid.
Depends on density. I think Scott Manley's analysis is probably correct. SpaceX knows how to deal with a few thousand watts of heat per satellite from starlink.
Then the question is whether a few kilowatts is enough compute per node to be worth the trouble.
No. In the vacuum of space there is no convection. The only maintenance free(ish) method of discharging waste heat is to radiate it as infrared, which is not terribly effective compared to terrestrial heat management systems where we have the benefit of a big old atmosphere to dump heat into.
Radiative cooling into space is seriously weaksauce. The amount of heat an object can dissipate in such a manner is described by the Stefan-Boltzmann Law. It would take nearly a square meter (0.84 m^2^ according to my admittedly possibly shaky math) of perfectly ideal thermally conductive black body radiator material to dissipate the 640 watts of waste heat from just one datacenter style GPU at 70° C.
A square meter of heatsink. For one GPU.
Your radiator heat sink can't be shaped like a terrestrial one, either, with stacked fins providing a high surface area in a small volume. That's because a black body radiator is not only an ideal emitter of heat into a vacuum, such as it is, but also an ideal receiver. Your heat sinks will have to be wide and flat so they don't radiate most of their heat right back into other parts of themselves, and this also precludes putting your equipment near other pieces of equipment so they don't radiate their heat into each other.
A single server rack in an AI data center will consume and thus have to dissipate something like 80 killowatts, i.e. 80,000 watts, which even if you had access to some type of physics-experiment-land totally ideal radiator material with an emissivity of exactly 1 would require a 102 square meter radiator just to dissipate that same 70° C. And no part of it could be baking in the sun, nor be influenced thermally by any adjacent servers. In reality it'd have to be even larger, because such a perfectly ideal material does not exist.
TL;DR: Getting rid of heat in space is extremely difficult and in fact is one of the biggest challenges of spacecraft design. Thus putting massive heat generating computers in space is a self-evidently moronic idea as cooling them would be effectively impossible.
Thanks for the thorough answer. I guess I'll just scrap this orbital data centre I was building.
One day we will figure out how to capture and store waste heat more effectively.
No idea when tho
And do what with it? You can't use heat to do work without there being temperature differential in the system. Maintaining that differential requires keeping your cold side cold, which means it still must dissipate its heat. In space you would have exactly the same problem doing that as just radiating that heat in the first place. Once your system reaches equilibrium between its hot and cold sides, no work could be done with that heat energy. It's just a radiator with extra steps.
If capturing heat energy to do something with it did not require sinking the waste heat from that selfsame process someplace, every satellite in orbit would already be covered in Peltiers or similar.
What if i just want to warm my hands or boil water
You can warm your hands until you reach thermal equilibrium, and/or use the boiling water to cool your system by allowing the water vapor to escape into space!
*Rocket fuel and other launch costs not included.
Just wanna boil pasta duh
The short version is - if you've ever heard of infrared cameras that can see heat, that's because everything glows based on heat. When things are very hot the glow is visible, but even cool things emit light outside of the visible spectrum. And emitting light takes energy, which means blackbody radiation (as this is called) takes energy (heat) away.
Jesus Christ, how do you think the Sun works? How are people this clustering ignorant!!??
That and the fact that space is not just extremely cold but also extremely hot, depending on what's between the subject and the sun.