[HN Gopher] When Bohr got it wrong: the impact of a little-known...
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When Bohr got it wrong: the impact of a little-known paper on
quantum theory
Author : sohkamyung
Score : 46 points
Date : 2025-02-03 12:19 UTC (10 hours ago)
(HTM) web link (physicsworld.com)
(TXT) w3m dump (physicsworld.com)
| gsf_emergency wrote:
| BKS virtual field -> pilot wave?
|
| https://en.wikipedia.org/wiki/De_Broglie%E2%80%93Bohm_theory
| naasking wrote:
| > "Its radically new approach paved the way for a greater
| understanding, that methods and concepts of classical physics
| could not be carried over in a future quantum mechanics."
|
| This is incorrect. The Hamiltonian in both statistical and
| quantum mechanics has the same basic structure. Quantization is
| the only real difference, but the other methods and concepts are
| structurally the same.
|
| > It was also a crucial factor in Heisenberg's argument that the
| probabilistic character of his matrix mechanics (and also of
| Schrodinger's 1926 version of quantum mechanics, called wave
| mechanics) couldn't be explained away as a statistical expression
| of our ignorance about the details, as it is in classical
| statistical mechanics.
|
| Too bad that's an incorrect inference. Bohmian mechanics proves
| that this inference is incorrect, and it's not the only
| possibility either.
| bowsamic wrote:
| Quantisation is a pretty big difference: it turns the
| observables into completely different mathematical objects.
| Also the Hamiltonian itself only has the same form as in
| classical physics if at most quadratic in the canonical
| variables
| whatshisface wrote:
| The parent commenter was talking about Von Neumann mechanics.
| fao_ wrote:
| I'm sorry but I think I'm going to believe the man who wrote
| the article, who is an editor of Nature and has a Physics
| PhD[1], over someone who has made it their life's work to argue
| against established scientists on a website for Venture
| Capitalists :)
|
| [1]: https://en.wikipedia.org/wiki/Philip_Ball
| whatshisface wrote:
| Would you believe two? :-) Bohmian mechanics describes a
| classical pseudo random number generator that
| deterministically decides the outcome of quantum
| measurements, using instant communication between
| measurements so that conditional probability works. The
| modern rejection of classical uncertainty as an
| interpretation of quantum uncertainty stems from Bell's
| theorem, which shows that any model that achieves a similar
| philosophical goal as Bohmian mechanics has a similarly
| dissatisfactory reliance on instant communication. People of
| Heisenberg's generation had the right intuitions and were
| guessing in the right directions but they did not know Bell's
| theorem, or even that it was a worthwhile question.
| leephillips wrote:
| This is an interesting article due to the historical connections
| it makes. I mention the paper in question on p. 120 of my book
| about Noether's Theorem (https://lee-phillips.org/noether) and
| quote Heisenberg on why violation of energy conservation, and
| therefore the paper, was unacceptable (something that the article
| doesn't really discuss--after all, other conservation laws were
| abandoned or modified as needed): it's because Noether's Theorem
| shows that energy conservation is equivalent to invariance with
| regard to time translation, something that no one would be
| willing to give up. This means that energy must be conserved in
| every interaction, not just statistically.
| ForOldHack wrote:
| Michelson-Morley got it wrong too, but getting things wrong, when
| you know its wrong, its an advancement.
| oneshtein wrote:
| LIGO is better version of Michelson-Morley experiment.
| goryramsy wrote:
| I'd never heard of that... do you have an article about it so I
| can read up?
| ioblomov wrote:
| The experiment disproved the existence of an ether by
| measuring that the speed of light was constant regardless of
| direction...
|
| https://en.wikipedia.org/wiki/Michelson%E2%80%93Morley_exper.
| ..
|
| (And special relativity soon showed that if the speed of
| light is constant, then time itself must be variable.)
| kazinator wrote:
| The experiment disproved the existence of stationary
| aether; it didn't disprove the existence of an aether
| dragged by the Earth.
|
| Relativity is radical. If we interpret it through the
| concept and language aether, it says that when two
| observers traveling at different velocities briefly meet at
| the same time and place, they will each observe an aether
| that appears to be dragged with them. That is a
| contradiction: how can the aether be simultaneously dragged
| in multiple directions at the same spot? So there cannot be
| an aether. But there must be something else, all the new
| cruft contained in Relativity, like dilation of time and
| space.
| baxtr wrote:
| _> But there must be something else, all the new cruft
| contained in Relativity, like dilation of time and
| space._
|
| Why must there be something else?
| kazinator wrote:
| To explain why everyone's interferometer measures the
| same light speed regardless of its orientation, or their
| relative motion past the same point.
| baxtr wrote:
| Ah ok got it.
|
| Thought you were talking about something else entirely.
| Didn't realize you meant the specialties of space-time in
| "special relativity".
| ithkuil wrote:
| I believe GP refers to the fact that they set out to measure
| the speed of the earth relative to the aether only to
| discover there was no such thing.
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