• LordCrom@lemmy.world
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    4 days ago

    Well, technically the earths magnetic field is a force field deflecting solar wind…otherwise we would be toast.

    • monotremata@lemmy.ca
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      4 days ago

      Yeah, I think this is the best answer. It also technically means that the Aurora Borealis is just the solar wind bouncing off our deflector shield, which is a pretty badass way to talk about that.

      The other example that’s arguable at this point is the magnetic confinement systems inside fusion reactors, which use powerful magnetic fields to constrain the hot plasma, to keep it away from the walls of the reactor. It’s basically the same principle, but in that case it’s actually a human-made field. It still only affects ions, though, which is pretty different from most sci-fi force fields.

      • Hamartiogonic
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        4 days ago

        Our current “forcefields” are super picky. They refuse to work with anything other than that one thing they were specifically designed for and the list of options is very short.

        If you want to deflect things with a magnetic or electric charge, we already have the right kind of “forcefield” for that. However, it’s not exactly the kind of shell you put around a space ship to keep it protected, so even in this limited sense we still have a long way to go. The magnetic field of the Earth directs some of the incoming particles to the poles, which isn’t really ideal if your goal is to deflect all incoming fire.

        If you want to protect the ship/planet from physical projectiles, we have no forcefields at all. That sort of stuff is just pure sci-fi at the moment.

  • MNByChoice@midwest.social
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    4 days ago

    Sci-fi only.

    As I write this, I am realizing there are different force fields in different Sci-Fi. So hard to argue without pinning down what we are talking about.

    I don’t think we even have a useful theory on how they could work.

    Charlatans claim progress periodically.

    Magnets are as likely to accelerate something as repel. Lots of things are no magnetic, or are made magnetic by a magnetic field, and then attracted.

    A plasma shield is going to be hot and burn shit, not stop it. Maybe we can do that. Going to suck power like mad though. I doubt we can do it and not burn the generator.

    • catloaf@lemm.ee
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      4 days ago

      Well, there’s also gravity. We’re still trying to figure that one out. Maybe there’s a way to emit gravity to produce a forcefield effect.

  • LostXOR@fedia.io
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    4 days ago

    Closest I can think to one is a plasma window. They can apparently separate atmospheric pressure from a vacuum with just plasma, but are restricted to being quite small with current technology.

  • Fondots@lemmy.world
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    4 days ago

    There’s a story floating around the internet, I can’t comment on its truthfulness, that 3M accidentally created one in one of their factories back in the 80s.

    Allegedly the plant made adhesive tape, and as such had enormous rolls of plastic that were being spooled or unspooled by machines at very high speed, and at one point the right conditions existed for static electricity to build up in such a way that it created a sort of invisible wall that people were unable to pass through.

  • april@lemmy.world
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    3 days ago

    Electromagnetism is very flexible and theoretically you could put a lot of energy in a small place with it and there’s things like a strong enough magnetic field levitating a live frog.

    That said it doesn’t seem very practical and it might not even be close to safe to walk around something with that much power like in the sci fi shows.

  • spittingimage@lemmy.world
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    3 days ago

    I watched a youtube video on that very question a couple of months back. The gist of it was that it’s possible to replicate several aspects of the forcefield concept, at great expense and limited utility, but the full package is impractical and will be for the foreseeable future.

  • Deconceptualist@lemm.ee
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    4 days ago

    I mean arguably all of physics is based on fields. And fields determine the trajectory of particles, which is more colloquially what we call a “force” acting upon those particles.

    So in the most literal sense, practically everything we can describe in the universe is a ‘force field’. Not a satisfying answer, I know.

    But you probably mean in the sci-fi sense of a thin geometrically constrained field that strongly affects particles within its limited boundaries but not those outside of it. That I’m less sure of. There are certainly the quantum mechanics 101 hypothetical problems where you assume a particle in a box with infinite energy barrier at the edges. But reality doesn’t play nice with infinity so whether such a thing can exist is much more murky. You can certainly have high (but not infinite!) energy there. But then you run into the whole issue of quantum tunneling which means a certain fraction still goes through. [AFAIK there’s no avoiding that.]

    • AwkwardLookMonkeyPuppet@lemmy.world
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      4 days ago

      I’m pretty sure a fraction still goes through Stat Trek shields too. If not, then why do sparks shoot out of the terminals and things catch fire when shields are still holding?

      • bunchberry@lemmy.world
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        3 days ago

        I always assumed that was because the shield was failing and so to maintain it they have to divert excess power to it, which fries their systems. Or, another interpretation is that impacting the shields causes a power feedback which drives excess power to it unintentionally, and again leads it to frying/sparking.