back to article Boffins spot weirder quantum capers as neutrons take the high road, spin takes the low

Imagine this: when Australian cricketer Shane Warne bowled “the ball of the century”, a delivery that drifted one way, then hit the pitch and spun the other, the reason batter Mike Gatting was bamboozled was because the spin took a different path from the ball. That's the phenomenon boffins claim they've observed in experiments …

  1. John G Imrie

    Ow!

    My brain has climbed out of my ears and is refusing to re enter my head unless I promise to stop reading this kind of stuff.

  2. Mark 85

    Too early for beer....

    my head hurts and there's no aspirin. Can we just shoot the cat for stomping on the carpet and spinning about? But not Schroedinger's. I think the box is soundproof.

    1. Anonymous Coward
      Anonymous Coward

      "Can we just shoot the cat "

      No.

      1. Martin Budden Silver badge
        Coat

        "Can we just shoot the cat"

        Maybe, we won't know until we've tried.

  3. Mike Bell

    What's a neutron?

    What is a neutron other than the composite of its properties?

    Isn't it more likely that some properties of a neutron go one way, and one or more properties go another, and the totality of the system is what we think of as a neutron? Rather than saying a quantum goes one way and a property of the quantum goes another?

    1. Anonymous Coward
      Joke

      Re: What's a neutron?

      Possibly more strange than that. It may be locality is out the window. It may be something temporal that's afoot.

      Or it may just be statistics...

  4. frank ly

    quantum oddness in the world

    " ... confronted with a double slit, even a single photon will exhibit wave-like behaviour ..."

    It used to be that we were amazed when light, known to be an EM wave propogating through space, behaved as if it were a stream of particles, which we called photons under certain circumstances and observations. Now, .......

  5. Neil B

    As usual, real-world quantum behaviour is weirder than anything we could make up...

  6. Anonymous Coward
    Anonymous Coward

    Oh, yeah?

    "If you looked at individual neutrons, the waveform collapses"

    Prove it. Here's a clue: you can't because it's mystical mumbo-jumbo.

    1. Christoph
      Boffin

      Re: Oh, yeah?

      Here is the proof. The fact that you are reading this.

      Current technology, especially electronics, depends critically on quantum mechanics being correct.

      Not just hand-wavingly 'about right', but exactly and precisely correct to many places of decimals.

      If the weird and non-intuitive properties of quantum mechanics were merely 'mystical mumbo-jumbo' then my computer would not work to read your message and write this reply. Your computer would not work to read my reply. The web server would not work. The Internet that connects them all would not work.

      Quantum mechanics is by far the most accurate description of how the Universe works that we have ever produced. Nothing else even comes close.

      Yes, it's weird. Yes, it's non-intuitive. Yes, nobody can really understand it. But the Universe doesn't care whether we understand it or not. It just goes on working that way.

      1. Anonymous Coward
        Anonymous Coward

        Re: Oh, yeah?

        @Christoph: everything you said in your post is wrong. There is no need to believe in waveforms collapsing when you observe them to explain any of that and in fact the superstition that observation collapses the waveform can be discarded without disrupting QM in any way. Bohr was a mystic and deliberately put his weird interpretation on the mathematics because it suited his world view with the complementarity bullshit.

        If you sit down and think about the Copenhagen interpretation it becomes clear that it depends on the existence of souls. Yes, souls! Some special thing that separates observer from observed; a special property that makes the cat's observation less valid than the experimenter who opens the box and looks. It's silly, it's nonsense, and it is totally unnecessary to make QM work just fine.

        If deBroglie or Bohm had presented their interpretations first we would never have heard about Copenhagen as the response would have been "well, that doesn't tell us anything different and it introduces this MASSIVE problem of why the waveform collapses; what's the point of this interpretation?"

        Separating observed and observer is mystical mumbo-jumbo, as I said.

        1. Mike Bell

          Re: Oh, yeah?

          @Robert

          Not really. A physical screen behind a couple of slits in Young's experiment count as an 'observer'. That screen doesn't require a soul in order to do its job. It is merely required to interact with the quantum world in such a way as to produce an outcome.

          1. Anonymous Coward
            Anonymous Coward

            Re: Oh, yeah?

            "That screen doesn't require a soul in order to do its job. It is merely required to interact with the quantum world in such a way as to produce an outcome."

            The collapsing waveform interpretation doesn't recognize that as an outcome. Or, rather, it is incapable of defining what is and is not an outcome. Certainly the specific example you gave is not something that would cause a collapse as it's nothing more than some quantum interactions - possible interactions and no different from asking which atom a specific electron is in.

            Again, I'm not arguing with QM or the results, just this nonsense that things don't exist until they're measured but the measurements somehow do exist. It's an infinite regression (turtles all the way down) and, as has been shown more than once since the 1920's, totally unneeded.

        2. Michael Wojcik Silver badge

          Re: Oh, yeah?

          Separating observed and observer is mystical mumbo-jumbo, as I said.

          And configuration space isn't?

          Bohm raises as many problems as he solves, and most of the problems he solves are philosophical ones (like the re-inclusion of the middle that so horrifies logicians). I think it's useful to study Bohm's interpretation, as an intellectual exercise - a QM paideia - but I don't see what pragmatic (in the popular or philosophical sense) advantage it offers.

      2. phuzz Silver badge

        Re: Oh, yeah?

        Quantum Physics isn't non-intuitive. Or rather, once you've learnt enough about it then it seems intuitively obvious that (eg) light can behave in particle-like ways, and wave-like ways depending on the circumstances.

        I'll admit that when you're first exposed to it it sounds odd, but you can use it to make testable predictions.

  7. hammarbtyp

    Great attempt at explaining the unexplainable

    Nice write up.

    For a brief second I almost understood it, then my brain underwent quantum wave function collapse and ended up in a lower energy state of denial and ignorance.

    On the plus side if some theories are correct there will be another universe where I fully understand the concepts and my brain is not hurting.

    1. Denarius
      Thumb Up

      Re: Great attempt at explaining the unexplainable

      indeed, good effort. Perhaps the various fields that make up the neutron via its quarks and the forces acting on them have the wave forms "smear out" and travel separately when a "decision" as to which way to go ? It is a weird place at those sizes. That attributes and object can travel separately suggests a field force carrier at work somehow, but that is speculation. Most interesting boffinry.

      Now back to improving my lousy limerick literacy

    2. HMB

      Re: Great attempt at explaining the unexplainable

      I can't say it better than the great man Douglas Adams:

      “There is a theory which states that if ever anyone discovers exactly what the Universe is for and why it is here, it will instantly disappear and be replaced by something even more bizarre and inexplicable.

      There is another theory which states that this has already happened.”

      1. Swarthy

        Re: Great attempt at explaining the unexplainable

        More than Once.

    3. Michael Wojcik Silver badge

      Re: Great attempt at explaining the unexplainable

      For a brief second I almost understood it

      I thought the material about Denkmeyr et al's paper and the Aharanov-Tolaksen experiment was pretty clear, but that cricket stuff was incomprehensible. Even with liberal application of Wikipedia.

  8. Inventor of the Marmite Laser Silver badge

    THREE states a cat could be in

    Alive, Dead, and Bloody Furious.” ― Terry Pratchett, Lords and Ladies

  9. Irony Deficient

    quantum physics has been as edin love with cats as Facebook

    Richard, what does “edin” mean?

  10. Frogmelon

    Wouldn't the ability to hive off and hide certain properties of a particle under a proverbial quantum carpet (at least for a short time) be great for developing anti-gravity, FTL travel, ignoring inertia to prevent pilot squish during extreme changes in vector etc.?

    Reality would have to catch up eventually (hopefully with a dose of amnesia) as you recombined the force with the particle, but by then it would be too late and your hypothetical interstellar spaceship would already be at Alpha Centauri...

    1. Anonymous Coward
      Anonymous Coward

      Sadly not. As it all still keeps to the rules of the universe. They are observed as no FTL travel/information propagation. That gravity (relativity) effects all things (though we have yet to look at things that small with gravity, as it's so week).

      Reality does not "catch up". The larger rules of the universe, hang on these smaller ones, so they are the same thing, they give the same results.

  11. Anonymous Coward
    Anonymous Coward

    I'd like to put it out there that I'm not a quantum physicist, but...

    It seems to me that when physicists come out with such convoluted and brain mangling explanations for stuff that they clearly have no intuitive explanation for, I have to wonder if they are really heading down the wrong path here.

    Remember the contorted explanations that the "earth at the centre of the universe and everything spins around us" troop had to bend themselves around to explain what they observed? The theories got stranger and unconvincing as time went on, until someone came along with something so much simpler that the complexity just sloughed off. I guess this is at least what the string theorists are trying to discover here: something more fundamentally true that makes everything that bit simpler and consistent.

    When doing physics at school, the wave/particle duality explanation never really convinced me as a viable hypothesis. Some vital piece is clearly missing from our understanding here.

    1. ian 22
      Black Helicopters

      @skelband

      You have been taken in by the Heliocentric Conspiracy! You can clearly see the sun rise in the East and set in the West. It is intuitively obvious the Sun moves and we are still! All else (moon landings, satellites, et al) is dross and falsehood.

      Mines the one with the tinfoil hat in the glove box.

      1. channel extended
        Devil

        Re: @skelband

        That's strange? That's where I keep my spare, in you're glove box. Are you spying on me!!?

    2. Anonymous Coward
      Anonymous Coward

      The duality bit is correct, but as you said the explanations sometimes fall short. Though that may not be the fault of science. The mathematical explanations fit well, perfectly even. It's just hard to articulate such explanations in general speech.

      Either because they use concepts we don't often meet in the macro world (like Born probabilities in QM).

      Likewise, the particle/wave explanation fits because light acts as both. It's either a thing that is both, and we have no word for that, or a system able to switch between them, which likewise we have no word for. Once we realise reality does not "have" to do anything, except what it does do, then it becomes easier to grasp.

      1. Anonymous Coward
        Anonymous Coward

        >Likewise, the particle/wave explanation fits because light acts as both.

        My suspicion is that the "wave" and "particle" concepts are inaccurate and insufficient to describe what is actually going on. In essence they are analogies, and neither is a very good fit and certainly in my case cause confusion rather than clarification.

        1. Scroticus Canis

          >Likewise, the particle/wave explanation fits because light acts as both @skelband

          Light is electro-magnetic in nature and both fields are needed to create a photon, as the electric field rises the magnetic field collapses and vice versa, the field are at right-angles to each other. This produces a 3D wave effect as the respective fields change from positive to negative polarity thus regenerating each other (like they are playing leapfrog with each other) and propagating through the medium. So each individual photon while being made from waves looks like a 3D particle. That's why it seems to behave as both.

  12. Anonymous Coward
    Anonymous Coward

    Hmph!

    Yet more dribble abouit an extremely difficult-to-detect particle. What's next? Slit experiments on the Higgs boson? Oh, wait, we gotta find a better way to produce the Higgs, before we can do any serious work with it. I gotcha! More money. Slippery particles, older whiskey, younger women, and more MONEY! What a racket.

    1. SDoradus

      Re: Hmph!

      Rather than simply downvote you like all the others, I have to ask: what makes you think the neutron is an "extremely difficult-to-detect particle"? It might have no net charge, but it certainly has a magnetic dipole moment. Which is why the experiment can be done at all, of course.

      1. Michael Wojcik Silver badge

        Re: Hmph!

        Rather than simply downvote you like all the others, I have to ask: what makes you think the neutron is an "extremely difficult-to-detect particle"?

        I guessed he was trolling, but Poe's Law is certainly in effect in a forum like this one.

  13. grumpy feline
    Alien

    Robert's not wrong.

    Wave collapsing is an attempt to reintroduce classical thinking. Sorry. It should go away along with the ether and non-relative speed of light.

    Mr Long might have been more diplomatic of course.

    For those who doubt, check out the delayed choice quantum eraser. Or more directly, Wigner's friend. Both tend, in my opinion, to make the global "wave collapse" idea a bit hard to sustain.

    In quantum world it's waves all the way to the bottom. "Particles" are a secondary effect, as is all locality and separation and indeed time (as Mr Bohm and friends tended to bang on about a lot).

    The hardware is wav-y and field-y and continuous.

    The software is particle-y, localized and discontinuous, but that is a secondary effect which breaks down more and more as you look closer and closer.

    For some people that is just too weird. I guess you pick your poison.

    1. willi0000000

      Re: Robert's not wrong.

      the observer requirement for collapsing the waveform (whatever that all means) seems a bit egotistical to me . . . i find it hard to believe that the universe only operates properly when being watched . . . like that slacker at the next desk.

      if we ever meet an advanced intelligence they are going to laugh whatever is their equivalent of asses off when we tell them that little bit.

      1. Michael Wojcik Silver badge

        Re: Robert's not wrong.

        the observer requirement for collapsing the waveform (whatever that all means) seems a bit egotistical to me

        Then you misunderstand what "observation" means in this context.

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