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Science

Objective Reality May Not Exist At All, Quantum Physicists Say (popularmechanics.com) 157

Long-time Slashdot reader waspleg shares a thought-provoking article from Popular Mechanics: Does reality exist, or does it take shape when an observer measures it? Akin to the age-old conundrum of whether a tree makes a sound if it falls in a forest with no one around to hear it, the above question remains one of the most tantalizing in the field of quantum mechanics, the branch of science dealing with the behavior of subatomic particles on the microscopic level.... Now, scientists from the Federal University of ABC (UFABC) in the São Paulo metropolitan area in Brazil are adding fuel to the suggestion that reality might be "in the eye of the observer."

In their new research, published in the journal Communications Physics in April, the scientists in Brazil attempted to verify the "complementarity principle" the famous Danish physicist Niels Bohr proposed in 1928. It states that objects come with certain pairs of complementary properties, which are impossible to observe or measure at the same time, like energy and duration, or position and momentum. For example, no matter how you set up an experiment involving a pair of electrons, there's no way you can study the position of both quantities at the same time: the test will illustrate the position of the first electron, but obscure the position of the second particle (the complementary particle) at the same time....

"We used nuclear magnetic resonance techniques similar to those used in medical imaging," Roberto M. Serra, a quantum information science and technology researcher at UFABC, who led the experiment, tells Popular Mechanics. Particles like protons, neutrons, and electrons all have a nuclear spin, which is a magnetic property analogous to the orientation of a needle in a compass. "We manipulated these nuclear spins of different atoms in a molecule employing a type of electromagnetic radiation. In this setup, we created a new interference device for a proton nuclear spin to investigate its wave and particle reality in the quantum realm," Serra explains. "This new arrangement produced exactly the same observed statistics as previous quantum delayed-choice experiments," Pedro Ruas Dieguez, now a postdoctoral research fellow at the International Centre for Theory of Quantum Technologies (ICTQT) in Poland, who was part of the study, tells Popular Mechanics. "However, in the new configuration, we were able to connect the result of the experiment with the way waves and particles behave in a way that verifies Bohr's complementarity principle," Dieguez continues.

The main takeaway from the April 2022 study is that physical reality in the quantum world is made of mutually exclusive entities that, nonetheless, do not contradict but complete each other.

Stephen Holler, an associate professor of physics at Fordham University, tells Popular Mechanics that the study underscores a famous observation by Richard Feynman: "If you think you understand quantum mechanics, you don't understand quantum mechanics."
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Objective Reality May Not Exist At All, Quantum Physicists Say

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  • Does that mean I really do?

  • False (Score:5, Informative)

    by fermion ( 181285 ) on Sunday July 03, 2022 @03:22AM (#62669260) Homepage Journal
    Classical mechanics assumes the things can go fast, things can be separated in arbitrarily small bit, measurement can be made arbitrarily precise and one can makes measurements with disturbing the thing you measure. Oh, and everything is a particle that is sometimes a wave

    What makes QM difficult is that so many consider classical mechanics the gold standard, instead of understanding the assumptions are false.

    In QM there are minimums determined by planks constant. It is not relevant to measure or take into account things smaller than this. For example, virtual particles are pooping in and out all around us. They would break conservation but the donâ(TM)t last long enough for the universe to notice.

    There are certain limits on what can be known. This can also be described in terms of thermodynamics. It takes a certain amount of energy to measure and store a value. To know something arbitrarily precisely, it would take an arbitrarily large amount of energy. So as things are finite, so it what can. be measured. With complimentary values, the measurement of one reducing the ability to measure the other.

    • There are certain limits on what can be known. This can also be described in terms of thermodynamics. It takes a certain amount of energy to measure and store a value.

      No, in the limit it takes no energy to store a value. What takes energy is resetting a value for the next measurement (if you have finite storage/read capacity). An arbitrarily large Maxwell's Demon brain uses no energy; a finite-sized one must generate entropy upon resetting its "neurons".

    • by gtall ( 79522 )

      Planck, the man's name was Planck. Planks generally do little more than act like boards, at least I've never observed them in any constants of nature.

      • I was more amused by

        virtual particles are pooping in and out all around us.

        So are we floating around in incalculable amounts of virtual excretive?

    • What makes QM difficult is that so many consider classical mechanics the gold standard, instead of understanding the assumptions are false.

      I posit that classical mechanics is a behavior that emerges as a result of quantum mechanics. This assumption allows quantum mechanics to follow it's own set of rules that do not conform to classical mechanics but ultimately producing the higher level behavior of classical mechanics.

      It's kinda like the difference because C and Assembly. C can't do all the weird stuff that you can do in Assembly but Assembly is what is used to implement the behavior of C. Ergo, the universe is a C compiler. QED ;)

    • by jd ( 1658 )

      The laws of thermodynamics are always statistical, and in QM the conservation laws are also. Quantum foam is several orders of magnitude larger than Planck lengths and Planck time, but the averages all work out correctly.

    • by kackle ( 910159 )

      For example, virtual particles are pooping in and out all around us.

      Is that why life stinks sometimes?

    • Wait. A German spouting no nonsense logic without really caring about feelings or popular opinion? I’m shocked. Shocked I say.
    • by bill_mcgonigle ( 4333 ) * on Sunday July 03, 2022 @09:48AM (#62669714) Homepage Journal

      I used to listen to her until I realized she makes a living by "debunking" any speculation by demonstrating that there's no definitive proof for it.

      The whole enterprise is based on the kind logical fallacy that would ensure that science never progresses.

      What's the documented process by which one conceives radical new hypotheses, Sabine? Our very existence depends on a long train of insights and ideas that came as dreams (benzene), literal daytime visions (Tesla's AC motor), acid trips (Internet), "bolts of lightning", muses and miracles.

      Not everything about science is neat nor tidy. Beating curiosity and wonder out of students is the Orthodoxy's aspie conception of sophistication.

      • by haruchai ( 17472 )

        Not everything about science is neat nor tidy.

        I think she would agree with you given her video about "beauty" in physics.
        A relatively low number of insights from borderline crazy people doesn't make the huge number of bonkers ideas worth considering.
        Curiosity & wonder are fantastic motivators but you still have to do the hard, boring, dirty work. Without that you can't progress beyond a collection of nifty ideas, most of which are wrong.

  • by Sique ( 173459 ) on Sunday July 03, 2022 @04:48AM (#62669302) Homepage
    The problem is the word Reality, which comes from the Latin 'realitas', derived from 'res', thing. Realitas is "the sum of all things". And to figure out reality, you first have to figure out what a thing is, where you run into the old problem of "the thing by itself".

    Other languages don't have that problem. In German, for instance, the word for reality is Wirklichkeit, which comes from "wirken", to have an effect. To the German speaker, reality thus is "the sum of all effects", and this is exactly how Quantum mechanics describes reality.

  • by evanh ( 627108 ) on Sunday July 03, 2022 @04:52AM (#62669310)

    Observation is irrelevant. Shit happens just fine without having observed it.

    We bloody well aren't in control! Nor should we expect to be.

    • If a particle decays and nobody observes it, is it really gone?

      And, more important, does anyone give a fuck?

  • Screw facts, what matters is how I feel is right.

    • by gweihir ( 88907 )

      Well, that is certainly how most people operate. It is not completely wrong though, because you cannot put a "fact" in your mind. You always will attribute it with stuff and build a model around it and give it a context. The real question is how you do this and how well it works for predictions. Most people screw that one more and more the more long-term the predictions become. Most people also employ feedback loops to warp new information to fit into their existing models instead of adjusting the models wh

      • I can. But then again, I'm not exactly what could be considered a normal human being.

        Yes, I have it in writing.

        I try to live my life rooted in this reality. To the utmost consequence. I admit, it's not what most people would probably want. Reality sucks. It's certainly far more pleasant to live in a fantasy world where you're always right and also the center of the universe.

        • by gweihir ( 88907 )

          I can.

          No, sorry, you cannot. There are several interface layers in between. After that, it is just an indirect reference, maybe with some indirect references as "explanation". The limit here is a fundamental information processing limit. Even text describing a "fact" is not a fact anymore. It is just text which requires interpretation.

          • Ah, another one who knows my mind better than I do. Great.

            • by gweihir ( 88907 )

              Ah, another one who knows my mind better than I do. Great.

              Nope. But I do know a bit about information processing and knowledge representation. All experience humans have of physical reality is very, very indirect. And that directly means you cannot put any fact about physical reality in your mind. That is simply not possible. All you can do is put a _description_ of a fact in there and those _always_ need interpretation and hence are not absolutes and not facts ion themselves. You can put logical/mathematical facts in your mind (I can too), but these do not apply

              • I'm fairly sure the experience of the fall of the iron curtain was a different for you than for me. I give you that. But the fact that it did is not up for discussion. It just is.

  • by Zobeid ( 314469 ) on Sunday July 03, 2022 @06:44AM (#62669418)

    This post makes me cringe so much. I'm sure there's actually some interesting science if you did deep enough, but. . .

    I really hate the word "observer" here. It makes it sound like a mind, a consciousness, is involved. In the quantum physics context, an observer is basically anything that interacts and is influenced by the particle. A block of wood can be an observer. An atom can be an observer. More broadly, the whole universe is an observer, with lines of cause-and-effect that tie everything together. But articles like this always spin it the exact opposite way, trying to imply that reality is some kind of collective fever dream dependent on human mental states.

    And even the old "tree falling in the forest" thing irks me, partly because it has absolutely no connection with quantum mechanics, but also because it was dumb to begin with. So let me spell it out. . . It's a purely semantic conundrum based on your definition of "sound". If sound is vibrations in the air, then a tree falling in the woods makes a sound, end of story. Some people, however, define "sound" as the perception of those vibrations by some kind of being, human or animal. Which seems weird to me, but okay. . . If that's your definition, then if there is nobody to perceive the vibrations, then I guess you would consider there to be no sound. But that doesn't reveal any sort of deep meaning about reality, nor does it reveal anything whatsoever about quantum phenomena.

    • by ODBOL ( 197239 )

      Mod up, but I've forgotten how to do that.

      Thanks for reminding us of the bogosity of the notion of conscious observer in physics.

      The Relational quantum mechanics [wikipedia.org] interpretation seems to be addressing this point sensibly, but I may not have understood it properly.

  • by paradigm82 ( 959074 ) on Sunday July 03, 2022 @07:28AM (#62669468)
    Seems doubtful how this could change anything. As I read it, they carried out an experiment that gave results that were consistent with the physical theory of quantum mechanics. Since all interpretations of quantum mechanics are by definition consistent with this theory, this experiment cannot shed more light on the interpretational/philosophical questions (objective reality, measurement problem etc.) claimed. Only if the experiment had actually shown a deviation from quantum mechanics, say, if it showed a threshold where quantum effects disappear (and this not due to normal decoherence which all interpretations agree on) could this experiment help us enhance the theory and it could eliminate some (or all) suggested interpretations.
  • by jd ( 1658 ) <(moc.oohay) (ta) (kapimi)> on Sunday July 03, 2022 @08:07AM (#62669520) Homepage Journal

    1. There's no objective reality

    2. As you approach the limit, the universe is objective but in a purely mathematical sense and not in a physical sense, the physical universe emerges from the mathematical objective reality

    3. As you approach the limit, the universe is objective but in a different space - such as a stringy 11-dimensional space, where the physical universe is a 4D spacetime slice through this high-order universe

    4. The laws are approximate and oversimplified, with more accurate laws in a granular 4D spacetime producing something that can be called an objective reality

    There is currently no way to distinguish cases 1,2 and 4. (3) can be distinguished iff the upgrade to the LHC will be enough to show up sufficient versions of supersymmetry to effectively rule this in or out, or a larger collider is built that can do so. (You cannot rule out all versions of supersymmetry, but the probability of them existing drops sharply as you increase complexity. At some reasonable point, you can draw a line and say that in the absence of any additional information, there's nothing beyond that we can meaningfully look for*.)

    *Using the cosmos itself as an accelerator is fine, we can create targets and see what spawns as a result of collisions. This is far higher energy that we could build on Earth, we just won't know what the energy was. But if supersymmetric particles arose, you'd at least know that there existed an energy where they did so.

  • I don't know this waveform nonsense could just be the universe simulations way of saving CPU Cycles by trying to not do work that nobody can observe.

    If we keep sending out more detailed observations devices then effectively we will just be slowing down our own simulations frame rate because there is more work to do per tick now.

  • i.e. seriously change reality because of these effects. Otherwise they will tend to remain unevidenced speculations that keep vast amounts of money flowing to the LHC and its ilk.

    OTOH given that parapsychology has long since observed effects that achieve levels of significance far above those required for publishing in the fields of medicine and biology, perhaps the parapsychologists need to be taken more seriously.

    Am I joking? I don't know...

    • > parapsychologists

      You can't do that with the high-school version of the Scientific Method.

      Something that has a high-water mark of 25% reproducibility with a 40% accuracy among the best subjects cannot be handled by those who insist "it must be consistently reproducible across the experimental arm".

      Most people calling themselves scientists don't understand statistical results. Most of them don't even do the stats for their own studies.

      That doesn't stop them from openly mocking you for the equivalent of t

    • by cstacy ( 534252 )

      OTOH given that parapsychology has long since observed effects that achieve levels of significance far above those required for publishing in the fields of medicine and biology, perhaps the parapsychologists need to be taken more seriously.

      Am I joking? I don't know...

      Please see "Cold Fusion".

    • Tree in a forest (Score:4, Insightful)

      by kackle ( 910159 ) on Sunday July 03, 2022 @11:11AM (#62669920)

      Am I joking? I don't know...

      Your joke isn't funny until someone thinks it is. ;)

  • ⦠my taxes are still due.
  • Independently observable and reproducible experiments at a distance calls bullshit.

  • ...we don't have to RTFA?

  • So let's just redistribute it according to hardship reasons!

  • ... assholes out of existence? Time to clean house!

"It's like deja vu all over again." -- Yogi Berra

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