> On 24 Apr 2018, at 21:59, Brent Meeker <meeke...@verizon.net> wrote: > > > > On 4/24/2018 11:48 AM, agrayson2...@gmail.com <mailto:agrayson2...@gmail.com> > wrote: >> >> >> On Tuesday, April 24, 2018 at 6:26:59 PM UTC, agrays...@gmail.com >> <mailto:agrays...@gmail.com> wrote: >> >> >> On Tuesday, April 24, 2018 at 6:14:49 PM UTC, Brent wrote: >> >> >> On 4/24/2018 9:24 AM, agrays...@gmail.com <> wrote: >>> >>> >>> On Tuesday, April 24, 2018 at 4:10:30 PM UTC, Brent wrote: >>> >>> >>> On 4/24/2018 12:03 AM, agrays...@gmail.com <> wrote: >>>> >>>> >>>> On Tuesday, April 24, 2018 at 5:14:25 AM UTC, scerir wrote: >>>> According to Kennedy tensor product (in QM) has a very interesting story. >>>> https://philpapers.org/rec/KENOTE <https://philpapers.org/rec/KENOTE> >>>> >>>> >>>> >>>> On the empirical foundations of the quantum no-signalling proofs >>>> <https://philpapers.org/go.pl?id=KENOTE&proxyId=&u=http%3A%2F%2Fdx.doi.org%2F10.1086%2F289885> >>>> J. B. Kennedy <https://philpapers.org/s/J.%20B.%20Kennedy> >>>> Philosophy of Science <https://philpapers.org/asearch.pl?pub=827> 62 >>>> (4):543-560 (1995) >>>> Abstract >>>> I analyze a number of the quantum no-signalling proofs (Ghirardi et al. >>>> 1980, Bussey 1982, Jordan 1983, Shimony 1985, Redhead 1987, Eberhard and >>>> Ross 1989, Sherer and Busch 1993). These purport to show that the EPR >>>> correlations cannot be exploited for transmitting signals, i.e., are not >>>> causal. First, I show that these proofs can be mathematically unified; >>>> they are disguised versions of a single theorem. Second, I argue that >>>> these proofs are circular. The essential theorem relies upon the tensor >>>> product representation for combined systems, which has no physical basis >>>> in the von Neumann axioms. Historically, the construction of this >>>> representation scheme by von Neumann and Weyl built no-signalling >>>> assumptions into the quantum theory. Signalling between the wings of the >>>> EPR-Bell experiments is unlikely but is not ruled out empirically by the >>>> class of proofs considered >>>> >>>> Wow! Thank you. It costs $10 to get a copy for a non-member, but very >>>> likely well worth it IMO. AG >>> >>> I wouldn't pay $0.01 for a paper written by a guy who says something is not >>> ruled out empirically by some mathematical proofs, and says something has >>> no physical basis in axioms. He seems very confused about the difference >>> between mathematics and empiricism. >>> >>> Brent >>> >>> I'll pay the money and see what he has to say. He's saying the tensor >>> product states do not follow from the axioms of QM. Seems pretty clear even >>> if wrong. But you can save me the fee if you can clearly state how the >>> tensor product states follow from First Principles, that is, from the >>> postulates of QM. AG >> >> Physics isn't mathematics. It's not required to derive everything from a >> few axioms. The mathematics is invented to describe the physics, no the >> other way around. If you want to understand the use of the tensor product >> in quantum mechanics read this: >> >> https://ocw.mit.edu/courses/physics/8-05-quantum-physics-ii-fall-2013/lecture-notes/MIT8_05F13_Chap_08.pdf >> >> <https://ocw.mit.edu/courses/physics/8-05-quantum-physics-ii-fall-2013/lecture-notes/MIT8_05F13_Chap_08.pdf> >> >> Equation 1.20 answers your question about singlets. >> >> Brent >> >> Thanks. This looks good. AG >> >> I can't copy and paste some pertinent paragraphs of the pdf scerir sent me, >> but from reading some of Kennedy's claims, he seem to be saying that >> although he doesn't dispute the validity and usefulness of tensor products >> in quantum mechanics, unlike other quantum axioms which ARE empirically >> based, tensor products are NOT empirically based. Perhaps your link says >> otherwise. AG > > Read this and then tell me what "empirically based" means > > https://pdfs.semanticscholar.org/2fb0/4475228ff385a44a16e3ba42b432d3bf5b17.pdf > > <https://pdfs.semanticscholar.org/2fb0/4475228ff385a44a16e3ba42b432d3bf5b17.pdf> > > As far as I know the only empirical basis for a theory is that it always > gives the right answer when empirically tested. Kennedy seems to have a > strange concept of circular reasoning. He says that adopting an equation > that implies no-signaling and then using it to prove quantum theory avoids > FTL signaling is circular. He misses the point that the reason for adopting > the no-signaling is the empirical success of special relativity, which would > be violated by FTL signaling.
I agree. Kennedy does not seems serious. Also, it is the first time I hear people criticising the tenor axiom axiom in Quantum mechanics, which is a fundamental postulate, but seems obvious in the old “de Broglie” “wave mechanics”. That motivation does not work well for the spin and discrete observable, but that is why von Neumann, in his famous treatise, makes it into an axiom, and indeed it has worked pretty well. Not sure if I could conceive a quantum mechanics without it. (To extract it from mechanism is another story, but the linearities and symmetries, + the quantum logic, suggested it would be astonishing we don’t get it, like it would be weird we don’t get an equivalent theorem to Gleason theorem). I will read the many post, as I have some time for a pause. I guess I will agree with Brent in this thread (so I will not have to add comments!). Bruno > > Brent > > -- > You received this message because you are subscribed to the Google Groups > "Everything List" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to everything-list+unsubscr...@googlegroups.com > <mailto:everything-list+unsubscr...@googlegroups.com>. > To post to this group, send email to everything-list@googlegroups.com > <mailto:everything-list@googlegroups.com>. > Visit this group at https://groups.google.com/group/everything-list > <https://groups.google.com/group/everything-list>. > For more options, visit https://groups.google.com/d/optout > <https://groups.google.com/d/optout>. -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at https://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
