You know like the kind that go on a window or bathroom mirror or on the wall or in the shower. They need the atmosphere pushing down on them to work, right?

  • NeptuneOrbit@lemmy.world
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    5 months ago

    Yes. They won’t work because they operate on a difference in air pressure providing a force. No air? No force. Same reason an airplane wing won’t provide lift in the upper atmosphere.

    But, compare to a rocket engine that does NOT need an atmosphere to push against.

    • ricecake@sh.itjust.works
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      5 months ago

      Phrases I did not expect to think this early in the morning: "what’s the rocket engine of suction cups?”

      • Shurimal@kbin.social
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        5 months ago

        Velcro, or maybe Van Der Waals force, or maybe whatever the hell makes gauge blocks stick to each other.

        • ricecake@sh.itjust.works
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          5 months ago

          I like the gauge block notion. A (quick) search says that it’s a combination of surface tension from the oils they’re coated in, suction (gone for us), and the super flat surfaces slightly exchanging electrons and bonding in close proximity.

          I’m a fan of the surface tension angle as the “rocket of suction cups”, since it’s got that “non-binding force” element, where welding or glue feels different, and Velcro feels like a tangle.
          It’s “pull-y” where suction is “push-y”.

          Now the question is would surface tension grab something in a vacuum the way it does outside of one. I know you’d have water sublimate off, so it’s questionable to me.

    • Buddahriffic@lemmy.world
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      5 months ago

      Just a technicality, but the Casimir effect would still provide some adhesive force. It would be greatly reduced vs a suction cup in an atmosphere, but it wouldn’t be 0 force.

      Though in microgravity, it might be enough to stick something to a surface, as long as it’s not getting bumped or jostled. And don’t expect it to stay in place if you need to do a maneuvering burn.

      Edit: fixed word

      • NeptuneOrbit@lemmy.world
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        5 months ago

        Yes the Casimir Effect.

        Any good answer to a high school science question begs for a graduate level rebuttal.

        • Buddahriffic@lemmy.world
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          5 months ago

          Ah thanks for the spelling, swipe typing had Kashmir already so I thought that was right. Corrected above.

          And yeah, even in high school I was lucky to have a physics teacher that liked delving deeper into the topics than what’s normally done at that level because my mind seems to naturally seek out those edge cases where rules as given break down. Still hoping we find one of those cases for the laws of thermodynamics lol.

    • Hol@feddit.uk
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      5 months ago

      Right. So just strap a Saturn V to my space suction cup and I’m golden?