Sort of similar to the Great Filter theory, but applied to time travel technology.

  • SmoothOperator@lemmy.world
    link
    fedilink
    arrow-up
    3
    arrow-down
    1
    ·
    edit-2
    7 months ago

    Quantum mechanics does not allow for FTL transmission. Disallowing information flow is the same as disallowing transmission.

    • cynar@lemmy.world
      link
      fedilink
      English
      arrow-up
      4
      ·
      7 months ago

      It seems to allow it, in a sense. The errors are also left on the transmission end. By transmitting them normally, the 2 signals can be combined to recreate the data. Something is shared, at some point.

      It’s definitely a “we’re not sure what’s actually going on” type situation though. Either both ends are drawing on some (otherwise) hidden data layer, or FTL transmission is allowed, so long as no information flows (information as defined by quantum mechanics). It just turns out that weird entanglement based systems are the only ones (we’ve found so far) able to send infomationless transmissions.

      Both solutions would give deeper insights into reality, and its underpinnings. Unfortunately, we’ve not actually teased out which is happening.

      My gut feeling is that the speed of light is a side effect of a fixed/stable causality across all rest frames. Hidden information seems to be a lot more cumbersome.

      • SmoothOperator@lemmy.world
        link
        fedilink
        arrow-up
        3
        arrow-down
        2
        ·
        7 months ago

        I’m not sure what you mean. If something is “shared”, but this something contains no information, how can we know that it was shared? In what sense does this something even exist?

        The perfect correlation of entangled particles is well established, and very cool, but perfect correlation does not require sharing of “something”. The perfect correlation is baked into the system from the start, from local interactions only.

          • SmoothOperator@lemmy.world
            link
            fedilink
            arrow-up
            1
            ·
            edit-2
            7 months ago

            Indeed. I’m not completely sure what point you are trying to make, but my point is not a hidden variable point. The states can be in a perfectly correlated superposition without any hidden variables, and still not “share anything” upon collapse into an eigenstate.

            I will concede that it looks a lot like one particle somehow tells the other “hey, I just collapsed into the |1> state, so now you need to as well”, but at a closer look this seems to happen on its own without any such message being shared. In particular, while the collapse of one state causes the collapse of the other, there is no physical way to distinguish between a state that was collapsed due to entanglement, and one that wasn’t. At least not until you send a sub-FTL signal to explain what happened.

            So if physically, the state of particle 1 before and after particle 2 was measured is indistinguishable, how can we say that “something” was shared from particle 2 to particle 1?