It's funny that world-leading physicists were arguing about these questions in the 40s (even if briefly), because I feel like nowadays, everyone who has played Civilization would've intuitively known Whittaker's argument to be flawed (at least those of us that like to savescum). A photon with hidden variables is essentially like playing a game of Civilization with the "preserve random seed" option enabled: if you reload a save and then take the same action (e.g. order unit X to attack unit Y) 100 times, you'll get 100 times the same result (e.g. unit X wins) — just like a deterministic photon would always take the same path. But if you load that same save and then take a different action (e.g. first order unit A to attack unit B, and then order unit X to attack unit Y) you may get a different outcome (e.g. unit X might die), because the PRNG from that same random seed is fed operations in a different order. The result can still be absolutely deterministic, but nevertheless dependent on external inputs. Same for the photon that could start acting differently in a way that is still tied to its hidden variable state when the environment it is confronted with changes (as if each quantum particle was seeded with its own little PRNG).
Of course Bell later proved by experiment that quantum state cannot be explained as simply as a local hidden variable, no matter how it looks like. But these guys didn't know that yet.
luc4 1 hours ago [-]
To give some nuance on the quote "Experimental evidence + logical deduction can never prove that either the deterministic or the indeterministic view is impossible": We can indeed rule out a local hidden variable model [1].
So if the deterministic view is true, then it has to be a holistic theory. The hidden variables must be global, i.e. "accessible" throughout the universe. They cannot be attached to a particle as in Whittaker's model or Schrödinger's modification.
The CHSH or Bell inequalities are based on quite dubious assumptions that seem a poor match for how real hidden variables should behave and the current quantum mechanics is still full of inconsistencies.
Much of the classic quantum mechanics, e.g. based on the Schrödinger or Dirac equations, is compatible with local hidden variables and I have not seen yet a precise account of which are the more recent axioms/assumptions that introduce an incompatibility with local hidden variables.
Thus I do not believe that the non-existence of local hidden variables has been proven beyond any reasonable doubt.
birdland 40 minutes ago [-]
There is another out, Bell assumes markovianity(The sum across conditional probabilities requires divisibility), the discrepancy disappears if the particle trajectories while unmeasured are non-markovian/indivisible. See the work of Jacob Barandes. This view allows for determinism just fine and does not require ftl communication or global constraints.
artnap 20 hours ago [-]
Schrödinger's fix to Whittaker's photon argument was to let the hidden variable take any value between zero and one, instead of just two. It's funny that such a small change was enough to rebuild the quantum probabilities.
adrian_b 1 hours ago [-]
It is not surprising that Schrödinger did this, what is surprising that a competent physicist, as Whittaker should have been, could ever write such an obviously weak "proof".
If there are hidden variables, it is pretty obvious that they cannot be binary variables, but their nature must be that of spins, i.e. rotation movements, where the probability of interaction depends on the instantaneous values of the rotation angles of the interacting particles (which correspond to the phases of the "wave" functions describing the system).
hackandthink 56 minutes ago [-]
Robert W. Spekkens (and I guess Matt Leifer) tried to model quantum uncertainty classically.
(my gut feeling was: it works till it does not work)
"In defense of the epistemic view of quantum states: a toy theory"
In a sense, "Indeterminism" implied by probabilities at the quantum level can be said to give rise to "Free Will" as the strict chain of cause and effect is broken at the fundamental level. Since there are multiple possible outcomes from the same starting conditions, "Consciousness" may be the causal agent (Observer?) which selects one of the possible outcomes i.e. "choice due to free will". Think of it as Physics leaving all options open for an event (within bounds) and Consciousness selecting one among the set. Since the probabilities must add up to one, at the aggregate macro level it is predictable and deterministic while being unpredictable and indeterministic at the quantum micro level.
yonisto 2 hours ago [-]
I was hoping it established that the cat is ginger
rramadass 1 days ago [-]
Great article on an interesting topic.
The article mentions the great Physicist, Prof. S.N.Bose's take in a lecture delivered to the Indian Science Congress in 1944. It is titled "The Classical Determinism and The Quantum Theory".
The corresponding pdf can be found at Prof.S.N.Bose archive under Section 6 "Documents" titled "Presidential address at the Indian Science Congress, Delhi,1944 [Current Science, Vol XIII, No. 1]" - https://www.bose.res.in/Prof.S.N.Bose-Archive/
Prof. S.N.Bose is the Physics great after whom "Bosons", "Bose-Einstein Statistics", "Bose-Einstein Condensate" and even "Higgs Boson" are named - https://en.wikipedia.org/wiki/Satyendra_Nath_Bose
srean 24 hours ago [-]
I find SN Bose's derivation of quantized distribution of energy levels so much more elegant than Plank's which reads more like a desperate hack to force a predetermined answer.
wolfi1 54 minutes ago [-]
Planck admitted it himself that it was a hack he just postulated that there had to be quants. It was Einstein when he explained 1905 the photoelectric effect that quanta were accepted as "real"
rramadass 42 minutes ago [-]
Prof. Partha Ghose in his paper The Story of Bose, Photon Spin and Indistinguishability does a nice walkthrough of Bose's derivation - https://news.ycombinator.com/item?id=50195940
Wikipedia has a telling quote from the Physicist, Prof. Partha Ghose;
Bose's work stood at the transition between the 'old quantum theory' of Planck, Bohr and Einstein and the new quantum mechanics of Schrödinger, Heisenberg, Born, Dirac and others.
I have always felt that Prof.S.N.Bose never got full credit and acclaim for his achievements maybe because there were so many other greats at that time though Einstein recognized his originality.
readthenotes1 3 hours ago [-]
A good example of a monster whose professional life benefits the world.
Worth the cost? I'd say not, but I'm generally an optimist.
abbadadda 3 hours ago [-]
Why was Schrödinger a monster in his personal life?
dabiged 3 hours ago [-]
The guy was a paedophile and justified it because he was so intelligent he deserved to sleep with children.
adrian_b 31 minutes ago [-]
Any human may have contradictory and uncorrelated aspects of personality, but nonetheless I find too difficult to believe such accusations.
Besides physics texts, Schrödinger has also written some more philosophical texts, which are very good and which show much more common sense than for many other physicists, past or present. The qualities of those texts seem quite incompatible with a deviant personality, like that of a paedophile.
In the absence of any concrete evidence, with all accusations based just on vague hearsay, I believe that it is much more likely that an accuser who has never done anything worthwhile is wrong, either non-intentionally or intentionally, than that the accused person, with a lifetime of great achievements, is guilty.
Moreover, even if the accusations of relations with young girls had been true, calling him a "paedophile" would not have been necessarily correct. What is classified as a paedophile in modern USA was not necessarily classified as such in other countries one century ago. In the past most European countries had much lower ages of consent than today, typically as low as 14 years.
"The guy was a paedophile and justified it" is a false sentence, because he certainly never admitted such a thing. The accusations were made post-mortem, based on hearsay, when he was no longer able to defend himself.
wolfi1 58 minutes ago [-]
it was never proven in a court of law, nor have there been accusations of any kind in this regard in his lifetime. it seems that Moore couldn't read Schrödinger's shorthand and he had to rely on other sources [0] [0]https://science.orf.at/stories/3237287/
danbruc 2 hours ago [-]
I had never heard that and just had a look at the Wikipedia article and those claims seem to be primarily based on one biography. Other research based on his journals disputes the image portrayed in the Moore biography.
Y_Y 36 minutes ago [-]
It "common knowledge" that that's why he ended up in Dublin
adrian_b 11 minutes ago [-]
Such strong accusations cannot be done based on "common knowledge".
They must be based on identified witness testimonies, to have any kind of validity.
justauserid 2 hours ago [-]
I just want to know what happened to the cat, eventually. Like for real – beyond the (academic) (un)certainties.
moehm 2 hours ago [-]
70 years later they looked it up and the cat is definitely dead.
wolfi1 2 hours ago [-]
Didn't you read Dirk Gently's Holistic Detective Agency?
ziiinq 2 hours ago [-]
[dead]
Rendered at 10:17:43 GMT+0000 (Coordinated Universal Time) with Vercel.
Of course Bell later proved by experiment that quantum state cannot be explained as simply as a local hidden variable, no matter how it looks like. But these guys didn't know that yet.
So if the deterministic view is true, then it has to be a holistic theory. The hidden variables must be global, i.e. "accessible" throughout the universe. They cannot be attached to a particle as in Whittaker's model or Schrödinger's modification.
[1] https://en.wikipedia.org/wiki/CHSH_inequality
Much of the classic quantum mechanics, e.g. based on the Schrödinger or Dirac equations, is compatible with local hidden variables and I have not seen yet a precise account of which are the more recent axioms/assumptions that introduce an incompatibility with local hidden variables.
Thus I do not believe that the non-existence of local hidden variables has been proven beyond any reasonable doubt.
If there are hidden variables, it is pretty obvious that they cannot be binary variables, but their nature must be that of spins, i.e. rotation movements, where the probability of interaction depends on the instantaneous values of the rotation angles of the interacting particles (which correspond to the phases of the "wave" functions describing the system).
(my gut feeling was: it works till it does not work)
"In defense of the epistemic view of quantum states: a toy theory"
https://arxiv.org/abs/quant-ph/0401052
In a sense, "Indeterminism" implied by probabilities at the quantum level can be said to give rise to "Free Will" as the strict chain of cause and effect is broken at the fundamental level. Since there are multiple possible outcomes from the same starting conditions, "Consciousness" may be the causal agent (Observer?) which selects one of the possible outcomes i.e. "choice due to free will". Think of it as Physics leaving all options open for an event (within bounds) and Consciousness selecting one among the set. Since the probabilities must add up to one, at the aggregate macro level it is predictable and deterministic while being unpredictable and indeterministic at the quantum micro level.
The article mentions the great Physicist, Prof. S.N.Bose's take in a lecture delivered to the Indian Science Congress in 1944. It is titled "The Classical Determinism and The Quantum Theory".
The corresponding pdf can be found at Prof.S.N.Bose archive under Section 6 "Documents" titled "Presidential address at the Indian Science Congress, Delhi,1944 [Current Science, Vol XIII, No. 1]" - https://www.bose.res.in/Prof.S.N.Bose-Archive/
Prof. S.N.Bose is the Physics great after whom "Bosons", "Bose-Einstein Statistics", "Bose-Einstein Condensate" and even "Higgs Boson" are named - https://en.wikipedia.org/wiki/Satyendra_Nath_Bose
Bose's work stood at the transition between the 'old quantum theory' of Planck, Bohr and Einstein and the new quantum mechanics of Schrödinger, Heisenberg, Born, Dirac and others.
I have always felt that Prof.S.N.Bose never got full credit and acclaim for his achievements maybe because there were so many other greats at that time though Einstein recognized his originality.
Worth the cost? I'd say not, but I'm generally an optimist.
Besides physics texts, Schrödinger has also written some more philosophical texts, which are very good and which show much more common sense than for many other physicists, past or present. The qualities of those texts seem quite incompatible with a deviant personality, like that of a paedophile.
In the absence of any concrete evidence, with all accusations based just on vague hearsay, I believe that it is much more likely that an accuser who has never done anything worthwhile is wrong, either non-intentionally or intentionally, than that the accused person, with a lifetime of great achievements, is guilty.
Moreover, even if the accusations of relations with young girls had been true, calling him a "paedophile" would not have been necessarily correct. What is classified as a paedophile in modern USA was not necessarily classified as such in other countries one century ago. In the past most European countries had much lower ages of consent than today, typically as low as 14 years.
"The guy was a paedophile and justified it" is a false sentence, because he certainly never admitted such a thing. The accusations were made post-mortem, based on hearsay, when he was no longer able to defend himself.
They must be based on identified witness testimonies, to have any kind of validity.