Need to let loose a primal scream without collecting footnotes first? Have a sneer percolating in your system but not enough time/energy to make a whole post about it? Go forth and be mid: Welcome to the Stubsack, your first port of call for learning fresh Awful youā€™ll near-instantly regret.

Any awful.systems sub may be subsneered in this subthread, techtakes or no.

If your sneer seems higher quality than you thought, feel free to cutā€™nā€™paste it into its own post ā€” thereā€™s no quota for posting and the bar really isnā€™t that high.

The post Xitter web has spawned soo many ā€œesotericā€ right wing freaks, but thereā€™s no appropriate sneer-space for them. Iā€™m talking redscare-ish, reality challenged ā€œculture criticsā€ who write about everything but understand nothing. Iā€™m talking about reply-guys who make the same 6 tweets about the same 3 subjects. Theyā€™re inescapable at this point, yet I donā€™t see them mocked (as much as they should be)

Like, there was one dude a while back who insisted that women couldnā€™t be surgeons because they didnā€™t believe in the moon or in stars? I think each and every one of these guys is uniquely fucked up and if I canā€™t escape them, I would love to sneer at them.

(Semi-obligatory thanks to @dgerard for starting this)

  • corbin@awful.systems
    link
    fedilink
    English
    arrow-up
    3
    Ā·
    2 months ago

    Iā€™m saying that we shouldnā€™t radiate if it would be expensive. Itā€™s not easy to force the heat out to the radiators; normally radiation only works because the radiator is more conductive than the rest of the system, and so it tends to pull heat from other components.

    We can set up massive convection currents in datacenters on Earth, using air as a fluid. I live in Oregon, where we have a high desert region which enables the following pattern: pull in cold dry air, add water to cool it further and make it more conductive, let it fall into cold rows and rise out of hot rows, condition again to recover water and energy, and exhaust back out to the desert. Apple and Meta have these in Prineville and Google has a campus in The Dalles. If you do the same thing in space, then you end up with a section of looped pipe that has fairly hot convective fluid inside. What to do with it?

    Iā€™m merely suggesting that we can reuse that concentrated heat, at reduced efficiency (not breaking thermodynamics), rather than spending extra effort pumping it outside. NASA mentions fluid loops in this catalogue of cooling options for cubesats and I can explain exactly what I mean with Figure 7.13. Note the blue-green transition from ā€œheatā€ to ā€œheat exchangerā€; thatā€™s a differential, and at the sorts of power requirements that a datacenter has, it may well be a significant amount of usable entropy.

    • skillissuer
      link
      fedilink
      English
      arrow-up
      4
      Ā·
      edit-2
      2 months ago

      okay so you want to put bottoming cycle thermal powerplant on waste heat? am i getting that right?

      so now some of that heat is downgraded to lower temperature waste heat, which means you need bigger radiator. you get some extra power, but itā€™d be a miracle if itā€™s anything over 20%. also you need to carry big heat engine up there, and all the time you still have to disperse the same power because it gets put back into the same server racks. this is all conditional on how cold can you keep condenser, but itā€™s pointless for a different reason

      youā€™re not limited by input power (that much), youā€™re more limited by launch mass and for kilogram more solar panels will get you more power than heat engine + extra radiators. also this introduces lots of moving parts because itā€™d be stirling engine or something like that. also all that expensive silicon runs hot because otherwise you get dogshit efficiency, and thatā€™s probably not extra optimal for reliability. also you can probably get away with moving heat around with heat pipes, no moving parts involved

      also you lost me there:

      pull in cold dry air, add water to cool it further

      okay this works because water evaporates, cooling down air. this is what every cooling tower does

      make it more conductive

      no it doesnā€™t (but it doesnā€™t actually matter)

      condition again to recover water and energy

      and here you lost me. i donā€™t think you can recover water from there at all, and i donā€™t understand where temperature difference comes from. even if thereā€™s any, itā€™d be tiny and amount of energy recoverable would be purely ornamental. if i get it right, itā€™s just hot wet air being dumped outside, unless somehow server room runs at temperatures below ambient

      normally radiation only works because the radiator is more conductive than the rest of the system, and so it tends to pull heat from other components.

      also iā€™m pretty sure thatā€™s not how it works at all, where did you get it from

      • self@awful.systems
        link
        fedilink
        English
        arrow-up
        5
        Ā·
        2 months ago

        and Iā€™m over here like ā€œwhat if we just included a peltier elementā€¦ but biggerā€ and then the satellite comes out covered in noctua fans and RGB light strips