Florin Moldoveanu wrote his review of Hardy's paradox. Like the GHZM experiment, it's some other "mostly qubits-based" quantum thought (or real) experiments that behaves inwards a way predicted yesteryear whatever local realist theory to endure impossible.
Florin's presentation is a flake shallower than my spider web log postal service on Hardy's paradox or his handling of the GHZM instance but I am willing to believe that he understands how it works.
The master copy newspaper yesteryear Lucien Hardy included the annihilation of an electron together with a positron into 2 photons; together with Jean Bricmont, a pro-Bohmian ideologue, late published his majority attacking the foundations of quantum mechanics. So I yell back it could endure a proficient instant to write a spider web log postal service dedicated to this specific topic of "Bohmian mechanics vs effects of QFT", something I withdraw keep wanted to attain for some time.
For some review of Bohmian mechanics, come across e.g. Bohmian mechanics is a ludicrous caricature of Nature. For a basic sketch of a key conceptual defect of Bohmian mechanics, ane that volition basically play role below equally well, come across Bohmian mechanics requires the unphysical segregation of primitive together with contextual observables.
OK. What's the problem? Bohmian mechanics is an ideologically driven candidate to supervene upon quantum mechanics (the theory discovered together with with rules rather carefully defined yesteryear Heisenberg, Jordan, Born, Bohr, Dirac, together with perhaps a few others inwards the adjacent moving ridge such equally von Neumann together with Wigner). Quantum mechanics says that facts most Nature alone be if they are truly observed yesteryear an observer, so the "state of a physical object/system" prior to the observation must endure described yesteryear complex probability amplitudes that generalize the subjective ("Bayesian") probabilities believed yesteryear the observer, non facts.
Bohmian mechanics is ane of the 3 primary philosophies attempting to furnish physics dorsum to the era of classical physics – physics associated with the 17th, 18th, together with 19th century where the observer played no of import role. In Bohmian mechanics, originally invented yesteryear Louis de Broglie inwards 1927 (but named afterwards Bohm who resuscitated inwards the 1950s – the theory is currently non beingness named afterwards de Broglie because de Broglie was an aristocrat patch Bohm together with almost all the fans of this theory were Bolsheviks) postulates that the uncomplicated edifice blocks of Nature don't withdraw keep particle-like together with wave-like properties depending on the method of observation.
Instead, Bohmian mechanics says that at that spot objectively exists a particle with a classical trajectory; together with at that spot also exists an independent laid of degrees of freedom, a classical moving ridge called the guiding moving ridge or airplane pilot wave. The latter behaves just similar the moving ridge percentage inwards quantum mechanics but has a unlike interpretation: it is analogous to a classical field. The guiding moving ridge directs the displace of the "actual particles" that be on peak of the waves so that the probability distributions for the "real particles" stay equally predicted yesteryear quantum mechanics. In other words, the guiding moving ridge repels the particles from all interference minima yesteryear the right "force".
In this way, assuming a random together with properly distributed initial seat of the actual particle, the experiment volition attain the right interference patterns inwards double slit experiments together with similar experiments. Bohmian mechanics may endure extended to \(N\) non-relativistic spinless particles: at that spot are \(N\) actual seat vectors of the particles, together with a guiding moving ridge inwards \(3N\) dimensions mathematically coinciding with the moving ridge percentage but interpreted equally a classical (multi-local) field.
Bohmian mechanics can't depict the spin – at that spot is no way to add together whatever "actual" information most the spin because whatever classical information most \(j_z\) etc. would pause the rotational symmetry. Bohmian mechanics is inwards severe conflict with relativity because the guiding moving ridge is a multi-local, i.e. non-local, object, together with it has to endure able to exert superluminal influences inwards guild to emulate quantum mechanics.
The right way to debate is that the generic theory inwards the Bohmian cast contains infinitely many Lorentz-violating effects together with they withdraw keep no argue to vanish. So the probability that all of them cancel together with attain the prediction of Lorentz-invariant phenomena – which are observed – is \(1/\infty^\infty\). It is null for all actual purposes. The theory is manifestly ruled out. It's been born dead because relativity had been known since 1905 together with Bohmian mechanics is fundamentally contradicting relativity. (Moreover, at that spot truly tin be no Lorentz-invariant dot inwards the Bohmian parameter spaces at all. The probability of relativistic predictions isn't just tiny, it is strictly zero.)
Bricmont is aware of the contradiction betwixt relativity together with Bohmian mechanics. But he doesn't work it to falsify the theory, Bohmian mechanics, equally a player inwards the scientific method would (theories are abandoned when they contradict the empirical data!). Instead, he calls the contradiction "the greatest job of physics today". Well, it's non a job for physics equally a dependent acre of science. It's alone a job for incorrect theories. Theories which are OK exist. Quantum acre theory together with string theory – together with when I say these names, it agency the matrimony of the full general "Copenhagen" postulates of quantum mechanics addition some particular choices of the Hamiltonian or S-matrix – are non excluded because they don't endure from this job at all. Within the quantum formalism, the Lorentz covariance of these theories is slow to endure demonstrated. It precisely holds. Does he neglect to empathise that fact? Or the importance of the fact for the "competition" betwixt the physicists' state-of-the-art theories together with his "theories"?
But the conflict with relativity is extremely far from beingness the alone lethal defect of Bohmian mechanics.
Bohmian mechanics cannot laissez passer a consistent explanation how the correctly distributed initial solid set down is prepared; together with what form of a janitor cleans the "garbage" guiding moving ridge away when a particle is absorbed. Without such a "janitor", the organisation would acquire contaminated yesteryear a growing issue of "dead souls", guiding waves that were needed but are no longer needed etc. Like all realist "interpretations", Bohmian mechanics contradicts the observed low rut capacities of atoms thank yous to its huge, infinite, issue of classical degrees of freedom.
However, I still believe that all these problems, patch plenty to kill the philosophy inwards a second, aren't the primary characteristic lethal bugs of Bohmian mechanics. There is something sick that is most intrinsically connected with the real assumptions of Bohmian mechanics. While Bohmian mechanics manages to emulate the wave-like demeanour of particles inwards the double slit experiment together with similar setups (the information most the relative phases is stored yesteryear the airplane pilot wave), it still contradicts the superposition postulate e.g. the characteristic of quantum mechanics that whenever at that spot are 2 or several possible states inwards which a physical organisation may uncovering itself, nosotros must ever depict these states yesteryear probability amplitudes together with the relative stage matters together with tin withdraw keep observable consequences.
Einstein famously asked whether the Luna was at that spot when no ane was watching. The right reply is that
in principle, fifty-fifty the interrogation most the existence of the Luna refuses to endure given an "objective" answer. Different answers (Yes/No) withdraw keep to endure represented yesteryear set down vectors inwards the Hilbert infinite together with an arbitrary complex superposition of these set down vectors is ever allowed!The instance of the Luna is (deliberately) misleading because all observers on the set down withdraw keep measured the reply to the interrogation whether the Luna exists, inwards ane way or another, together with got the reply Yes. So their moving ridge functions are collapsed together with alone alive inwards the Yes subspace of the Hilbert space. The amplitudes for all the No states are null – the alone province of affairs inwards which at that spot is no information most the relative phase. However, for much smaller objects than the Luna (because they're non beingness observed all the time), the existence of superpositions of "exists" together with "doesn't exist" becomes damn practical together with damn slow to experimentally verify!
I've mentioned that Bohmian mechanics has a serious job with at to the lowest degree 2 primal features of quantum acre theory: the spin of particles; together with the Lorentz covariance. But it truly has a serious job with all conceptually novel effects yesteryear which quantum acre theory differs from non-relativistic quantum mechanics. It isn't compatible with the particle creation together with annihilation. The calculations of renormalization can't endure embedded into Bohmian mechanics inwards whatever way.
And inwards fact, the real simple insight that at that spot are loop (Feynman) diagrams inwards quantum acre theory contradicts Bohmian mechanics at the real primal level.
Take the anomalous magnetic instant of the electron. The electron exists inwards the initial solid set down together with the concluding state; that produces the 2 fermionic external lines. And at that spot is ane external photon job because the electron is interacting with some external magnetic acre together with nosotros desire to know how potent the modify of the electron's velocity is. The primary classical term is given yesteryear the Feynman diagram including the simple cubic vertex only.
The pictures inwards a higher house laissez passer us the leading quantum corrections – one-loop diagrams that modify the classical prediction for the magnetic instant yesteryear relatively pocket-size but safely measurable amounts. It's truly the showtime diagram (a) that gives us the leading term, \(\alpha/2\pi\), to \((g-2)/2\) (the subtraction is meant to cancel the classical term). The other diagrams are cancelled inwards the physical outcome because they right the 3 external particles (their propagators) individually, non their interaction.
This \(\alpha/2\pi\) term was first calculated yesteryear Julian Schwinger inwards 1948 – using a calculational framework that looked less elegant than the Feynman diagrams nosotros similar to work these days. It's a whopping 68 years ago. Communists just conquered Czechoslovakia inwards 1948. Both my parents were born on that year, too. They were conceived during republic together with born into totalitarianism. Believe me, it's a long fourth dimension agone when loop corrections started to endure computed.
The argue I am maxim it is that the Bohmists inwards 2016 believe that they may still totally ignore all these insights. They fool themselves into thinking that it is non a problem that their philosophy is totally incapable of explaining these calculations yesteryear Schwinger together with millions of similar calculations that all of particle physics is most today.
And this manufacture of loop corrections started yesteryear Schwinger has grown a lot yesteryear 2016, indeed. Corrections upward to five-loop diagrams withdraw keep been computed, producing a prediction for the magnetic instant that has the accuracy of fifteen important figures, together with my ex-colleague Jerry Gabrielse together with co-authors has experimentally verified that all these digits are nontrivially right. The electron's magnetic instant remains the most accurately verified prediction inwards natural (let lonely social or otherwise unnatural) sciences.
Now, let's come across what the calculations of the loop diagrams truly hateful e.g. for Bohmian mechanics. Imagine that nosotros compute the Feynman diagram inwards the seat space. We know what the diagrams are doing. Feynman was truly summing over all possible histories of the particles. Each possible history contributes a complex probability aAmplitude to the total one. The initial particles are propagating from ane spacetime dot to some other (with amplitudes given yesteryear the propagators) together with they are allowed to merge together with dissever (at the cubic vertices). When all these histories are summed over, nosotros acquire the probability aAmplitude for the overall development from the initial solid set down to the concluding state.
This sum-over-histories may also endure shown to endure equivalent to some intermediate development of the moving ridge percentage for the whole laid of quantum fields. The fact that the histories are numerous together with they differ from each other at some particular intermediate moment, e.g. \(t=0\), equally good truly agency that if yous evolve the moving ridge percentage yesteryear the accurate Schrödinger's equation, the intermediate solid set down at \(t=0\) volition endure a superposition of real unlike states.
Now, yous may ask. In the midpoint of the history (the experiment that measured the sensitivity of the electron's displace to the magnetic field, i.e. the magnetic moment), at \(t=0\), how many electrons, positrons, together with photons were acquaint inwards the space?
The reply is the same equally the reply to whatever similar interrogation most the solid set down of the organisation that is truly non observed. The reply is:
We didn't truly mensurate the issue of photons, electrons, together with positrons at \(t=0\), so the interrogation expecting a clearcut classical reply is just meaningless. Only quantities that are truly measured withdraw keep well-defined values (one of the eigenvalues that just managed to endure measured). At \(t=0\), nosotros withdraw keep to depict the solid set down of the quantum fields equally a full general complex superposition of states with unlike values of \(N_{e^+}\), \(N_{e^-}\), together with \(N_\gamma\).There just can't endure a clear answer. Superpositions of states are ever allowed, fifty-fifty if the states differ yesteryear the issue of photons or electron-positron pairs. The relative stage matters together with influences some inwards regulation measurable interference patterns.
You may come across that
- this fact – the allowed superpositions of "anything" – is absolutely critical for the theory's predictions to depend on the total of Feynman diagrams with unlike numbers of loops
- the superpositions of states with unlike numbers of particles are fundamentally prohibited yesteryear Bohmian mechanics (if the issue of particles is allowed to overstep away upward or downward at all, the modify of the issue must endure "objective", observer-independent)
The 2nd dot is truthful because the whole dot of Bohmian mechanics is to restore realism at the primal level. When yous restore realism, some of the measurable properties or their functions only withdraw keep to endure objectively true. In the criterion Bohmian non-relativistic mechanics for \(N\) particles, the issue of particles is an "objective fact". So at that spot tin never be states of the form\[
\ket\psi = \frac{ 3 \ket{e^+ e^-} + 4i \ket{ e^+e^+ e^-e^- } }{5}
\] The configuration of the Bohmian degrees of liberty always explicitly says whether the issue of electrons together with positrons is \(1+1\) or \(2+2\) (or something else). But inwards quantum acre theory, complex superpositions of both states (the "Schrödinger's truthful cat states", if yous wish) must ever endure allowed. And the relative stage matters for some doable experiments. This is fundamentally incompatible with the basic cast of Bohmian mechanics, the alone ane that is truly discussed inwards many Bohmian papers, namely the non-relativistic theory of \(N\) spinless particles.
One may say that Gabrielse's successful measuring of the precise electron's magnetic instant experimentally proves that
the 5 electron-positron pairs and/or extra photons aren't objectively at that spot when no ane is looking.They demand to endure described yesteryear the superpositions. It's non quite the same declaration equally ane most the Luna (which is larger than 10 or so leptons) but it is qualitatively the same. The measuring of the magnetic instant only shows that whatever right theory must allow yous to mix the states into quantum superpositions fifty-fifty if they withdraw keep unlike numbers of particles inwards them. By confirming the prediction based on the total of multi-loop Feynman diagrams, the interference betwixt the histories with these intermediate states is beingness almost straight measured!
Influenza A virus subtype H5N1 Bohmian apologist could advise that this job may endure fixed yesteryear choosing a unlike laid of "beables". In the normal Bohmian theory, the guiding moving ridge together with the positions of the particles "objectively exist", they are "beables". The intelligence "beable" was chosen yesteryear Bell who was driven yesteryear his hatred towards proper quantum mechanics together with whose finish was to mock the dependence of quantum mechanics on the observers, together with thence the intelligence "observables" equally well. Things shouldn't endure just observed, they should be, all these anti-quantum zealots ever claimed inwards contradiction with the results of the physics research.
But whatever your "beables" volition be, yous volition unavoidably ban most superpositions. To claim that some properties of the physical organisation are objectively real, independently of an observer, is so fundamentally unlike from the basic postulates of quantum mechanics, namely that all states may endure mixed into complex superpositions together with observations are needed to withdraw keep whatever "classical facts", that yous may ever easily come across a huge contradiction betwixt Bohmian mechanics together with quantum mechanics – or, almost equivalently (because quantum mechanics together with QFT truly concord with everything nosotros withdraw keep tried), betwixt Bohmian mechanics together with the experiments.
Imagine that the basic "beables" of a Bohmian theory include classical values of the electromagnetic field. There is some classical electromagnetic acre \(F_{\mu\nu}(\vec x)\), afterwards all, together with its values are driven yesteryear some guiding moving ridge which is at nowadays a functional on the infinite of all possible functions \(F_{\mu\nu}(\vec x)\) – well, in all likelihood just the canonical coordinates \(\vec A(\vec x)\), i.e. the airplane pilot moving ridge is a functional \(\Psi[\vec A(\vec x)]\).
To some extent, it's excellent. In this setup, the Bohmist may "simulate" all the relative phases betwixt the unlike "continuous functional set down vectors" of a quantum acre theory. But the description with these "beables" is likewise wave-like together with it volition endure impossible to explicate how photons may ever endure detected at particular points. Why?
You must empathise that the primary "beables" inwards the master copy Bohmian theory – the particles' positions – were chosen precisely because Bohmists realized that those are the things that "must endure possible to endure measured", together with they don't similar the superpositions of unlike outcomes (they don't similar when a particle "spreads" to many places, equally the dissolving moving ridge percentage indicates using their sloppy interpretation). That's why they included the configuration infinite of particles' positions – because that's a frequent measuring that may manifestly endure done – equally extra classical degrees of liberty inwards their theory. The particles are "preemptively ready" for the most typical form of a measurement, the measuring of their positions. And the Bohmists were implicitly assuming that every measuring is ultimately beingness reduced to a measuring of particles' positions.
In this way, Bohmists believed that they had solved the (non-existent) "measurement problem": no collapse is needed because the soon-to-be-measured location of the particle is already known earlier the measuring – it's the classical location of the "particle-like" percentage of the Bohmian classical degrees of freedom.
But the novel Bohmian theory is alone ready for a measuring of the value of the fields \(F_{\mu\nu}(\vec x)\). It's no proficient because the measuring of the locations of quanta tin inwards no way endure reduced to a measuring of \(F_{\mu\nu}(\vec x)\). If yous desire to guarantee that the theory volition honour a photon at ane particular place, yous volition need a collapse, anyway. You volition demand to borrow parts of the "standard quantum mechanics" because no value of the location \(\vec x\) of the photon is "ready" earlier the measurement. So the real argue why Bohmian mechanics was constructed inwards the showtime house breaks down. The novel Bohmian theory won't endure capable of producing abrupt results for the most commons experiments. Before yous mensurate the location of a high-energy photon, no "beable" seems to know what outcome yous should get. It's clear that the "right result" tin endure neither a percentage of the guiding functional, nor the classical values of the fields \(F_{\mu\nu}(\vec x)\). So the Bohmian theory just can't maybe endure able to predict what happens inwards the seat measurement.
If yous included both the particle positions together with the fields' values with your beables, yous volition confront fifty-fifty worse problems. The corresponding operators inwards quantum mechanics don't commute with each other, so it's ever a job if yous claim that a theory determines both at the same moment. In the most full general measurements, yous volition withdraw keep no thought whether the outcome should endure given yesteryear ane beable or another. (Imagine the similar mess inwards the normal 1-particle Bohmian theory if yous added both a classical value for \(x\) equally good equally ane for \(p\) which would differ – together with endure to a greater extent than well-defined than – \(dx/dt\).) And if the theory chose to say that yous must pick the "most relevant beable" from this redundant set, it volition contradict all the experiments such equally GHZM, Hardy's, together with Bell's experiments.
Moreover, at that spot is another, technical but widespread, immediate job with the "beables that are the classical values of the fields" inwards a Bohmian theory attempting to emulate quantum acre theory. Influenza A virus subtype H5N1 job is that
the fermionic fields can't withdraw keep whatever classical values at all.There can't endure whatever (nonzero) classical values of the fermionic fields because those would endure Grassmannian numbers which anticommute with each other. But no 2 nonzero numbers \(a,b\) obey \(ab=-ba\). So at that spot doesn't fifty-fifty be a mathematically possible configuration infinite for these "fermionic acre beables". This strategy is completely failing for fermions!
Just to endure sure, quantum mechanics has never whatever job with the "non-existence of particular Grassmann numbers" because nosotros never mensurate them. Everything that nosotros tin truly mensurate yesteryear apparatuses are functions of the fields that ever include "even powers" of the Grassmann numbers (or integrals/derivatives over a issue of Grassmann variables which is correctly fifty-fifty or odd, equally needed), so these observables are basically commuting. The observables nosotros may mensurate are Grassmann-even. Equivalently but non "obviously" so, yous may say that quantum mechanics alone predicts probabilities together with those terminate upward beingness integrals over the Grassmann variables (these are highly abstract, formal, "Berezin" integrals) such that whatever dependence on the Grassmann numbers goes away inwards the concluding result.
One may say that the Grassmann numbers are just "building blocks" that are never straight "observed" inwards isolation (like quarks, but at a much to a greater extent than primal level). The real dot of Bohmian mechanics is that it is trying to claim that all these intermediate objects inwards quantum mechanics are "real". This is an indefensible assertion for dozens of reasons, many of which withdraw keep been enumerated inwards my spider web log posts (and above). And ane of them is that "the Grassmann numbers can't endure beables at all" because there's fifty-fifty no mathematically possible candidate configuration infinite inwards which they could accept values.
But the success of QED shows that the fermionic fields (e.g. the Dirac acre creating electrons together with positrons) are almost certainly extremely natural parts of successful descriptions of Nature. Bohmian theories just don't allow yous to build anything that would comprise things similar "Grassmann fields". Quantum acre theory with Grassmann fields was already getting started around 1930 – thank yous to the pioneering piece of work yesteryear Jordan, Dirac, together with others. If yous yell back that the mathematics of the fermionic fields should endure included inwards "some way" inwards a promising theory/interpretation to supervene upon the Standard Model, yous may eliminate the Bohmian epitome because it's clearly incapable of dealing with Grassmannian fields.
So these Bohmists are totally overlooking or denying particular phenomena that withdraw keep been pillars of physics for to a greater extent than than 85 years. They don't withdraw keep a problem. Despite this consummate lack of viability of their pseudoscientific theory, they claim that it's a competition to proper, i.e. observer-based ("Copenhagen"), quantum mechanics, if non a ameliorate competitor.
The stupidity together with arrogance of these Bohmian together with related morons is shocking. Jean Bricmont's 2016 book is a scary instance of that. As I withdraw keep said, it unsurprisingly ignores all these phenomena that were the "core" of physics enquiry from the 1930s if non the 1920s, including fermions, particle production, loop corrections, renormalization, together with so on. The philosophy sold inwards the majority is absolutely incompatible with all these things. He must know that if a reader buys this stuff, he is fooled because this materials volition endure unusable equally long equally he volition attempt to bargain with a somewhat to a greater extent than modern job – fermionic fields, spin, statistics, relativity, renormalization, ... – but he doesn't care.
That didn't forestall Bricmont from de facto claiming that almost all the peak physicists of the 20th century were idiots. He hasn't fifty-fifty dared to consider the explanation that it's him, Bricmont, together with non these peak physicists, who is the intellectual midget. Bricmont says that the courses of quantum mechanics inwards the college withdraw keep never made whatever feel to him together with he seems proud most it.
He faithfully quotes lots of the slap-up men who were explaining the divergence from classical physics clearly together with unambiguously. They used unlike words (something Bricmont would dearest to abuse equally "disharmony" equally good – but it's natural for unlike men to work unlike words) but all of them say that it's physically meaningless to inquire most the solid set down of a physical organisation earlier (or without) an actual observation etc. The authors of the quotes that Bricmont reprints include
Niels Bohr, Werner Heisenberg, Max Born, Pascual Jordan, Wolfgang Pauli, John von Neumann, Eugene Wigner, Rudolf Peierls, Bernard d'Espagnat, David Mermin, Anton Zeilinger, fifty-fifty Margaret Thatcher ;-), Aage Petersen, Leon Rosenfeld,while Pauli together with Dirac are also quoted inwards the "neutral" section. (That's also misleading because these quotes also say that it's perfectly right that the theory – quantum mechanics – says zip most the "state of the system" prior to the observations.) Just imagine that. These people are some of the pillars of the 20th century physics. It's possible that just this pocket-size grouping is collectively responsible for to a greater extent than than 50% of the genuine progress inwards physics inwards the 20th century. And the progress was closely linked to the quotes.
But Bricmont just doesn't withdraw keep a job to say that these physicists' insights most physics just "didn't brand sense" – just because Bricmont is a peabrain incapable of agreement quantum mechanics together with peculiarly its defining characteristic that it may alone endure applied relatively to an observer together with pre-given classification "what is an observation" – together with he chooses to hash out whether they're a "fringe group". They're certainly non a fringe group. Every proficient physicist knows that they were right patch their critics such equally Einstein, Schrödinger, Bell, Bohm, ... were wrong. Influenza A virus subtype H5N1 physicist may stay soundless because he's non interested inwards these philosophical debates together with he knows how to truly work the laws of physics inwards cases he cares most but when he says something, he can't contradict the basic rules he is truly using inwards his work. This fact is non a thing of interpretations. It's a percentage of the basic cognition of physics. You only shouldn't endure allowed to overstep an undergraduate or graduate course of didactics of quantum mechanics if you're incapable of getting this uncomplicated dot – e.g. that Bohr was right together with Einstein was incorrect inwards their debates.
There are lots of 100% crackpots such equally Bricmont together with so at that spot are the "confused" people similar Florin Moldoveanu who sometimes write something indicating that they empathise something, e.g. the workings together with implications of the GHZM or Hardy's experiment, but they instantly neutralize it yesteryear maxim that Bricmont's is a well-argumented defense forcefulness of Bohmian mechanics. Does Moldoveanu truly believe this crap or does he lick the aß of the aßes similar Bricmont for fiscal reasons? Because he may demand their recommendation letters?
Bricmont's majority doesn't ever advert things from modern physics such equally the spin, loop diagrams, Grassmann numbers etc., I've mentioned that – those things easily exhibit that Bricmont together with other Bohmians are total of crap. But he doesn't fifty-fifty endeavor to hash out things that are undoubtedly relevant inwards these discussions, according to his "soulmates" inwards the "foundation community". The majority alone mentions the GHZM experiment inwards ane content-free footnote; together with Hardy's paradox is alone sketched together with "responded to" yesteryear a bizarre quote yesteryear Bohmist Sheldon Goldstein who said that the "problem is with the problem" together with "there is no contradiction because at that spot are unlike ensembles every fourth dimension yous repeat the experiment".
Oh, really? Is that supposed to endure a sufficient reply preventing Bohmian mechanics from beingness instantly excluded thank yous to Hardy's paradox, too? In Hardy's paradox, whatever local realist theory predicts the probability of a sure combined outcome to endure \(P=0\) patch experiments together with quantum mechanics say \(P=1/16\). Could yous delight exhibit us the calculation inwards Bohmian mechanics that reproduces \(P=1/16\)? This is a real simple or uncomplicated experiment. If you're non capable of getting \(P=1/16\) inwards your theory claimed to endure relevant for these real phenomena, together with yous say that it's "OK" for your theory nevertheless, yous realize that it becomes obvious that yous lack all the integrity needed to attain science, don't you?
It is non OK. Hardy's paradox is ane way with hundreds to exhibit that Bohmian mechanics – its detailed versions but also its totally universal assumptions together with philosophy – is utterly incompatible with the experimental facts inwards modern physics. It's extremely shameful that people similar Bricmont attempt to obscure this basic fact. It's shameful that the likes of Moldoveanu attempt to defend the indefensible.
BTW I haven't heard most Bricmont equally a physicist earlier – at most I could withdraw keep thought he was an assistant of Alan Sokal's inwards the battles with the postmodernists. But I could withdraw keep predicted that he was an extreme leftists. After the spider web log postal service inwards a higher house was written, I looked at Wikipedia together with learned that he's active inwards all sorts of far left-wing causes together with collaborates with Noam Chomsky, too. The correlation betwixt the ideological garbage together with scientific garbage is far from perfect but it is safely positive, too.
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