In Hilbert space, all things are quantumly possible

(quantamagazine.org)

60 points | by unprovable 4 hours ago

8 comments

  • djsjajah 2 hours ago
    Not all things are possible, only potentially possible ones. If you take all the numbers between zero and one, you will find an endless supply of distinct numbers but none of them are 3.
    • tcdent 2 hours ago
      Aren't you really just talking about the level of abstraction being applied? If there are infinite possibilities between zero and one, then it's just our way of relating to it that imposes the perception of a limitation.
      • djsjajah 33 minutes ago
        No. You might be reading into it a little bit too much. My point was that finding three needs to be possible for you to find it. If you are looking on the interval 0-1, it is not possible. As other comments have kinda of suggested, you could map every integer to a real and find "three" but if you are going to do that, why not just look on an interval that actually contains the number?
      • packetlost 2 hours ago
        Maybe you can theoretically encode arbitrary (but not infinite) information, but there are still discrete underlying states.
        • fc417fc802 1 hour ago
          > encode arbitrary (but not infinite) information

          What leads you to claim that you can't encode infinite information given an infinite set to work with?

      • mathisfun123 2 hours ago
        Terrence Howard is that you?
    • lolakutty 1 hour ago
      And can't one do all of mathematics without 3...(just map all the numbers > 1 to points inside the interval 0-1)?
  • rootedbox 31 minutes ago
    Just a reminder.. Hilbert space is just a tool/abstraction/map... and the map is not the territory..
    • dr_dshiv 20 minutes ago
      Yes! But at some level, doesn’t it kind of get blurred?

      That is, we are trying to come up with rules describing the underlying rules, right? The world isn’t made of stuff, it’s made of rules, right? Or math? Just not the same notation, at least.

      Help! I feel like I’m falling off a metaphysical cliff!

    • japanuspus 17 minutes ago
      No. The Hilbert space is the territory. Our perceived classical world is the map.
  • dbvdh 28 minutes ago
    It’s not ‘all’ things that are possible, just things that are allowed within the laws of physics :)

    Subtle difference, but energy conservation for example has to be adhered to.

  • rozgo 3 hours ago
    "I would like to make a confession which may seem immoral: I do not believe absolutely in Hilbert space anymore." - John von Neumann
    • kdavis 1 hour ago
      Surprising that he could have that intuition in 1935, before the Unruh effect was known of, before AQFT was invented, and really before most of QFT was formulated.

      But then again, he was John von Neumann.

  • ocschwar 3 hours ago
    "What is a Hilbert space?"

    -- David Hilbert.

    • cgio 2 hours ago
      The nice additional reading is that you could even know what a Hilbert space is, but not what is a Hilbert space.
  • inshard 1 hour ago
    Superdeterminism... quantum noise and the which way paths are all correlated.
  • thrill 3 hours ago
    [flagged]
    • katzgrau 3 hours ago
      Or, there is no time. Awareness traverses the grand graph of possibility.

      Disclaimer: total armchair philosophy.

    • SantalBlush 3 hours ago
      Given infinite time, is it possible to randomly draw a rational (instead of an irrational) from the interval [0, 1]? And if so, is it possible infinite times?
      • rablackburn 2 hours ago
        Finally, a well-formed question to which the answer "42 (times)" is a possible solution.
      • LPisGood 2 hours ago
        Certainly! Probability 0 does not mean impossible.
        • voxl 2 hours ago
          In this case it does. Describe any effective measure to pick a random sample from the interval and you will have cheated into choosing from the computable reals instead (of which there is a countable amount)
          • fc417fc802 1 hour ago
            I don't think that's correct. You're describing a limitation of our physical computing devices (or perhaps physical reality itself) as opposed to a theoretical flaw. At least as far as I can tell.
          • LPisGood 30 minutes ago
            Measure 0 is different than empty.
      • adrianN 2 hours ago
        "Randomly" drawing anything from [0,1] is already quite difficult.
        • taneq 1 hour ago
          You could draw a line, or a Cantor dust. ;)
  • georgestones 1 hour ago
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