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Ask Slashdot: After We're Gone, the Last Electrical Device Still Working?

Posted by Soulskill on from the all-the-robots-that-killed-us dept.

Leomania writes: After watching a post-apocalyptic Sci-Fi short on YouTube (there are quite a few) and then having our robot vacuum take off and start working the room, I just wondered what would be the last electric/electronic device still functioning if humans were suddenly gone. I don't mean sitting there with no power but would work if the power came back on; rather, something continuously powered, doing the task it was designed for. Are we talking a few years, decades, or far longer?

7 of 403 comments (clear)

  1. satellites by Anonymous Coward · · Score: 5, Insightful

    Probably satellites would last the longest, with maybe Pioneer or Voyager probes for however the RT batteries last.

    1. Re:satellites by AmiMoJo · · Score: 5, Funny

      A Nokia 3310 will outlast them all.

      --
      const int one = 65536; (Silvermoon, Texture.cs)
      SJW, n: "Someone I don't like, and by the way I'm a fuckwit" - AC
    2. Re:satellites by Strider- · · Score: 5, Informative

      Either my understanding of orbital mechanics is completely wrong or that is completely incorrect. Geostationary satellites need very regular station keeping otherwise they either fall to Earth or are ejected out into solar orbit. If ejected it could remain operational for a while but if it fell back to earth the results would be obvious.

      Your understanding of orbital mechanics is totally wrong. Geostationary satellites do need frequent stationkeeping maneuvers, but that is because the satellite is required to remain in a 30km box. If these maneuvers cease, as would happen with the sudden disappearance of humans, they will start to drift off their stations, eventually collecting in a couple of regions, one over the Indian ocean and the other over the Pacific. (This is due to the earth's slightly uneven gravity). Because of the vastness of space, the probability of them actually running into each other is fairly low.

      A geostationary satellite would need almost the same amount of energy to come down as it takes to put it up there, and probably twice as much to escape the earth's gravity well. At the end of life of these satellites, they use the remaining fuel to boost them another 200km or so in altitude, then vent all remaining fuel (so they won't explode if there's a fuel leak), and then blow the electronics to make sure they don't interfere with anything else. They will remain in that graveyard orbit forever.

      --
      ...si hoc legere nimium eruditionis habes...
  2. XKCD answered this by slart42 · · Score: 5, Interesting

    A very similar question was in an XKCD "What If?", but only in the printed book version (which has a bunch of extra chapters compared to the blog): "What would be the last artificial light source to glow when all humans were gone".

    IIRC, the conclusion was that it would be status LEDs on space probes or radiation glow from buried nuclear waste.

  3. Probably the Oxford Electric Bell by Chrisq · · Score: 5, Informative

    The Oxford Electric Bell has been running since 1840 and will probably carry on for a long time yet

  4. a data collection device in antarctica by lkcl · · Score: 5, Interesting

    andrew trigdell told me an amazing story back in 1999 about how he helped install Linux 0.99 on a solar-powered data collection computer in antarctica. Linux 0.99 was known to be highly stable, hence why it was chosen. it has a 56k modem which is enough to get the data back, and to check (very slowly) that it's still operational. so i think anything that's designed for long-term with those kinds of harsh remote and inaccessible conditions in mind, powered off of sustainable independent power, would be a good candidate for a device that would still be functioning even decades later.

  5. Re:That would be useless wiring weight by AikonMGB · · Score: 5, Interesting

    We don't design LEDs into our own boards, and we explicitly remove them from COTS boards that we use. Generally speaking the diffusers on LEDs outgas, meaning a) they are depositing materials on your spacecraft surfaces (bad) and b) could result in a shorting risk (also bad). There may be space-grade LEDs that big-space (think Hubble, JWST, Voyagers, etc.) use but I would be surprised. There's simply no need.

    "Is it plugged in? Is it turned on? Is it on frequency?" solves about 99% of basic device connection issues. An LED will make one very short portion of that slightly shorter, and then only when testing on the bench, since you can't see it as soon as you box it up. As soon as you can talk to a device, you are able to run a long form functional test on it, exercising every part of the design and ensuring everything is working correctly. If it passes, you're good. If it fails, you pull the unit.

    For ground support equipment, yeah sure, throw an LED on every rail and switch output.