Physicists Disagree Wildly on What Quantum Mechanics Says About Reality (nature.com)
- Reference: 0178524002
- News link: https://science.slashdot.org/story/25/07/31/146255/physicists-disagree-wildly-on-what-quantum-mechanics-says-about-reality
- Source link: https://www.nature.com/articles/d41586-025-02342-y
Another 15% support the many-worlds interpretation. Researchers split evenly on whether a boundary exists between quantum and classical worlds -- 45% said yes, 45% said no. When asked about the wavefunction's nature, 47% called it a mathematical tool while 36% considered it a representation of physical reality. Only 24% of respondents expressed confidence their chosen interpretation was correct, with others viewing their preference as merely adequate or useful in certain circumstances.
The survey contacted over 15,000 researchers whose recent papers involved quantum mechanics, plus attendees of a centenary meeting on Heligoland island. Despite quantum mechanics enabling technologies from computer chips to medical imaging, physicists remain divided on the physical reality underlying the mathematics.
[1] https://www.nature.com/articles/d41586-025-02342-y
Quantum mechanics: a mathematical description (Score:5, Insightful)
Quantum mechanics is a mathematical description of reality.
The tricky confusion comes in trying to answer the question "what does it mean?" The answer seems to be, it means that if you follow the equations using the correct approach, it will give you answers that are correct.
David Mermin tagged the approach to the question actually used by physicists the "shut up and calculate" approach.
Q: What does it mean?
A: Shut up and calculate.
Re:Quantum mechanics: a mathematical description (Score:5, Interesting)
I think the fundamental mistake that is made, and it is a very natural one, is that humans can actually understand reality. There simply was no survival value in having an intuitive grasp of quantum mechanics so it just did not arise in nature. The senses we have evolved to have work only in a very narrow band in the scale of the universe, and so our neural nets never see quantum effect or cosmic effects.
But we do very well in the world in which we actually live, and that leads to the feeling that we can actually understand anything.
Re: Quantum mechanics: a mathematical description (Score:2)
i think it's good to question whether reality is even understandable in the QM regime, but i think you weaken your point by appealing to survival value. there's loads of things which had no survival value back when we were hunter-gatherers but which we're pretty good at. driving cars, for example. understanding electromagnetics. playing piano.
Re: (Score:2)
You can develop an intuition for quantum mechanics if you play with it enough. In the same way you develop an intuition for gravity, although maybe not always intentionally. In the same way you develop intuition about anything you develop intuition about.
Our senses are well suited to observing quantum mechanical effects, especially those involving light. We can see light without needing special instruments. (I say although I do wear spectacles.) There is a lot of fun to be had with polarised glasses an
Human understanding of reality is limited (Score:3)
I'll push back on this a bit.
No, our senses don't see quantum effects, unless you mean "everything we see in nature is ultimately built on quantum mechanics, so everything is a quantum effect," which makes the statement true but trivial. We see light, but we don't see the quantum nature of light: we don't experience single photons. Polarization is completely a classical effect. Polarization in quantum mechanics works on the single-photon scale differently from polarization in classical mechanics; the two a
Re: Quantum mechanics: a mathematical description (Score:2)
A lot experiments show that the fundamental nature of quantum mechanics is true - and for now, no upper limit for the size of the system following the rules of quantum mechanics have been found. If we then extrapolate and say the fundamental mathematics hold on all scales, we end with a "many world" interpretation, which for me just means that the quantum state of our conscious minds get entangled with the quantum state of say the atom in the SchÃdinger's cat experiment, when we observe the cat.
Re: (Score:3)
> A lot experiments show that the fundamental nature of quantum mechanics is true - and for now, no upper limit for the size of the system following the rules of quantum mechanics have been found.
Well, yes and no. While I'm personally sure that quantum mechanics works at all scales, do note that the largest system that has been exactly solved in quantum mechanics is the hydrogen atom: two components. The quantum state of the helium atom, even in the ground state, has never been solved, although we can do finite-element approximation. This tends to get left out in your physics courses. The mind-boggling complexity of the quantum state of a cat is way beyond our comprehension (not even getting to the
Unsurprising (Score:5, Insightful)
While a lot of complaints are made, and justifiably, that some more modern Theories and hypotheses aren't testable, there are a lot of aspects of Quantum Physics from the turn of the twentieth century that are likewise untestable. Youtube channel Kurzgesagt just posted a video on the Many Worlds interpretation that frankly left me annoyed, because it itself demonstrated confirmation bias while claiming that it was proof of the Theory. Normally I really like their videos, but this one left me doubting that they had done as much research on the topic as they claim to do.
The problem is that they can do a whole bunch of very useful mathematics that can lead to results, but that doesn't mean that the intermediate steps in the math are as ultimately true as the final result appears to be. Remember, at one point humanity thought Newton was right, but subsequent math from Einstein demonstrated a better mathematical model to match observations. The mathematics in some aspects of Quantum Physics might well match observations well, but that doesn't necessarily mean that there aren't better mathematical explanations for what we see that that humanity hasn't managed to devise.
When aspects of Quantum Physics can be experimentally demonstrated, like quantum tunneling, then it's fairly safe to conclude that those aspects are largely settled, but for things like Many World, the concept of the collapse of the wave function, even the definition of the term "observer", it becomes harder to take some claims especially seriously.
Re: (Score:2)
"Remember, at one point humanity thought Newton was right, but subsequent math from Einstein demonstrated a better mathematical model to match observations."
Newton WAS right, Einstein didn't invalidate Newton. All theories have limitations, some more limiting than others.
Re:Unsurprising (Score:5, Interesting)
The [1]orbit of Mercury [wikipedia.org] would disagree that Newton was, strictly speaking, right.
Isaac Newton was one of the smartest human beings to ever live, but even he acknowledged, "if I have seen further, it is by standing on the shoulders of giants."
He knew how he got where he did scientifically and he knew that others would come after him that would improve upon the knowledge that he himself had improved upon. There's no shame in having created the best, most rational explanation for something, and explanation that stood for hundreds of years as best, before an even better explanation could be devised.
[1] https://en.wikipedia.org/wiki/Tests_of_general_relativity#Perihelion_precession_of_Mercury
Re:Unsurprising (Score:4, Interesting)
The thing is, our observations agree with quantum mechanics to as many decimal places as we can measure, and we can measure to a lot of decimal places now. So there's a lot of evidence that the wave function describes the behavior of reality. And since reality really seems to behave this way, we're left to ask interesting philosophical questions, like whether there really is no free will, or if reality is non-local. These are fascinating and important questions.
Re: (Score:2)
I won't dispute that.
The trouble is, there are still folks who think that, "the observer" means consciousness . The term "observer" itself is a problem. The double-slit experiment demonstrates that quantum effects are more than just interaction because arguably the slit assembly as a filter is an interaction, but the "observer" seems to be a slightly more involved interaction.
Of course, the word, "Theory" was also a bit of a poor choice because those who wish to dismiss science will use, "it's just a theor
Theoretical field mired in theories. (Score:2)
This is a shocking revelation.
I hope these survey results make their way to Hollywood. I can't wait for their highly accurate interpretation of these disagreements. Maybe they can get Paul Rudd to explain it to us?
9% of respondent playing silly buggers (Score:2)
[QUOTE]
Does a measurement require an observer?
9% Yes and they must be conscious.
[/QUOTE]
mathematical tool or representation of reality? (Score:2)
"When asked about the wavefunction's nature, 47% called it a mathematical tool while 36% considered it a representation of physical reality"
It's hard to take this seriously. It is either both or neither and anyone surveyed would understand that. Either this is gross malpractice or the survey itself is too poorly constructed to be useful.
better headline: physicists are unsure what QM say (Score:2)
with only 24% reporting high confidence that their interpretation is correct i wouldn't describe them as "disagreeing wildly".
Multi-universe for me (Score:2)
And I'm hoping this one will pop into a better one soon.
Re: (Score:1)
Sorry, this universe is stuck with Microsoft. Maybe your fork-clone is enjoying the Linux Universe, but you can't cross the boundary to share that joy.
Learn from politicians (Score:2)
The smarter ones gave Schrodinger answers that can't be proven false because nobody can test Reality Path B in this universe.
Well, test the interpretations. (Score:2)
I would contend that it should be possible to find an implication of each interpretation that only exists in that interpretation. If, for example, Many Worlds is true, then it necessitates that any sort of information cannot be destroyed and vice versa, when considering the system as a whole. If Many Worlds is false, then superposition information is lost when superposition collapses, you cannot recover from the collapsed wave a complete set of all superposition states that existed. I'm sure that someone wi
I both agree and disagree (Score:5, Funny)
Asking me which will affirm one.
Re: (Score:1)
Your cat is shaking in a corner, hoping you never answer.