• Voroxpete@sh.itjust.works
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    4 hours ago

    You need to think about how an infrared laser works. You’re taking electricity, converting it into light and then focusing the light.

    So you’d need to take the heat from your GPUs, inefficiently convert it into electricity (a lot of it would remain as heat), then inefficiently convert electricity into light (much of the electricity would turn back into heat in this process) and then focus the light away from the space data centre.

    Now, we already have a process for moving heat away from things as infrared light, without going through all those steps (which would just reduce the efficiency of the process). It’s called a radiator, and it’s how we cool things in space. That’s literally where the name comes from; they radiate heat away as infrared light. That’s why hot things glow in thermal cameras.

    It is incredibly inefficient. Radiation (ie, infrared light) is, by far, the worst way of cooling things. But in space its the only option you have, because there’s no convection or conduction across vacuum.

    A top end GPU puts out about 1,000 watts of waste heat. The entire International Space Station has enough cooling for 14 of those, if it was doing nothing else whatsoever. An average server rack contains 72. The ISS cost $100 billion dollars. So at a minimum you’re looking at around $500 billion to put one single server rack in space. And that’s before accounting for the heat from the sun, which we can’t avoid because we need solar power to run this thing. So probably closer to a trillion. In other words, twice the already ludicrous price tag of Sam Altman’s “Stargate” project. For a single server rack.

    • elephantium@lemmy.world
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      2 hours ago

      But in space its the only option you have

      Hmm, this has me thinking about the stealth ships in The Expanse. The engineering needed to make it work makes me want to cry, but in principle you could run a Peltier cooler with a swappable heat sink.

      To be clear, I don’t think this is a viable option, but it’s interesting to think about.

      • Voroxpete@sh.itjust.works
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        1 hour ago

        Basically the way you would make a stealth spaceship would be by focusing as much as possible on energy efficiency. At every juncture you would try to use as little power as possible, and use every bit of it as efficiently as possible, so that you’re not remitting waste. That waste, in the form of heat, radio waves, etc, is what gets you spotted.

        You could also run heatsinks temporarily for enhanced stealth as you suggest, then open up radiators to cool them - or eject them - once it’s safe to do so.

        (For the Elite: Dangerous players, yes, that game got it right.)