• @Brainsploosh@lemmy.world
    link
    fedilink
    English
    69 days ago

    Honest question: what happens afterwards? When we’ve stopped observing, does it reassemble into it’s superpositive form? Are we depleting quantum states somehow?

    • @kayzeekayzee@lemmy.blahaj.zone
      link
      fedilink
      English
      3
      edit-2
      8 days ago

      Sorta! According to the Heisenberg Uncertainty Principle, there’s an upper limit to how much we can “know” about the given state of a quantum system. This isn’t an issue with our measurements, but a fundamental property of the universe itself. By measuring one aspect of a quantum system (for example, the momentum of a particle), we become less certain about other aspects of the system, even if we had already measured them before (such as the position of the same particle).

      Though (as far as we know), we aren’t going to run out of quantum states or anything like that.

      • @Brainsploosh@lemmy.world
        link
        fedilink
        English
        38 days ago

        Thank you for your answer!

        Maybe I’m too dense, but what happens with other quantum states that aren’t position/velocity based? I’m thinking things like when we collapse spin, e.g. in entangled particles.

        I’ve heard that entangled particles are “one use”, I’d assume they can be restored and possibly re-entangled, but how?

        • @kayzeekayzee@lemmy.blahaj.zone
          link
          fedilink
          English
          4
          edit-2
          8 days ago

          Good question! You are certainly not dense!

          The position-momentum uncertainty relationship is just a specific case of a more general relationship. There are other uncertainty relationships, such as between time and energy or between two (separate/orthogonal) components of angular velocity. The relationships basically state that whenever you measure one of the two values, you are required to add uncertainty to the other.

          Unfortunately, this is kinda where my knowledge on the subject starts to hit its limits. As for spin, it has a lot of effects on the energy of the system it’s involved with, so I believe the energy-time or angular momentum exclusion principles would apply there.

          You might also be thinking “why not have two entagled cloned particles, and measure the momentum of one and the position on the other?”. While you can duplicate particles, there are reasons why that doesn’t work that I don’t really remember tbh. I’m sure PBS Spacetime on Youtube has an episode on it somewhere though if you’re interested