Dear All,
There is an intense debate on validity of Bohm’s theory/hypothesis/interpretation is going on this blog!! Admittedly, I have not read Bohm’s or Sutherland’s papers. But these days there are so many papers published that no one can read all of them. Now, number of physicists on this blog is a tiny, tiny, tiny fraction of total number of physicists. I read many physics blogs also. So far none of the top level physicists has come out in favor of Bohm/Sutherland’s theory. If you say it is a matter of time and my attitude is unscientific. Science should not be a popularity contest! Ok! It is possible that 1000 persons may be wrong and one person may be right. But I think, Bohm/Sutherland’s theories have still terrible problems. Quantum mechanics works beautifully in the present linear form and it agrees with experiment to better than 1 part in a billion or more. If Bohm/Sutherland have to make it highly non-linear to make it compatible with experiments, nobody is going to buy it, not even on Einstein’s authority! By the way, Einstein was probably the greatest scientist ever born , but he was wrong in connection with quantum mechanics (God does not play dice and EPR reality issue). So, although I have an open mind, in my heart, I seriously doubt if these efforts to make QM realist will succeed. Personally I like non-realistic interpretation of QM in agreement with Advaita (Maya) philosophy. Again, since there is no consensus about interpretation of quantum mechanics after 90 years of debate, may be something very subtle could be going on!
Best Regards
Kashyap
--
----------------------------
Fifth International Conference
Science and Scientist - 2017
August 18—19, 2017
Nepal Pragya Pratisthan, Kathmandu, Nepal
http://scsiscs.org/conference/scienceandscientist/2017
Send a Donation to Support Our Services: http://scienceandscientist.org/donate
(All Indian residents are eligible for tax benefits for their contributions under section 80G of the Income Tax Act)
Report Archives: http://bviscs.org/reports
Why Biology is Beyond Physical Sciences?: http://dx.doi.org/10.5923/j.als.20160601.03
Life and consciousness – The Vedāntic view: http://dx.doi.org/10.1080/19420889.2015.1085138
Harmonizer: http://scienceandscientist.org/harmonizer
Darwin Under Siege: http://scienceandscientist.org/Darwin
Princeton Bhakti Vedanta Institute: http://bviscs.org
Sri Chaitanya Saraswat Institute: http://scsiscs.org
Sadhu-Sanga Blog: http://mahaprabhu.net/satsanga
Contact Us: http://scsiscs.org/contact
---
You received this message because you are subscribed to the Google Groups "Sadhu-Sanga Under the holy association of Spd. B.M. Puri Maharaja, Ph.D." group.
To unsubscribe from this group and stop receiving emails from it, send an email to Online_Sadhu_Sa...@googlegroups.com.
To post to this group, send email to Online_Sa...@googlegroups.com.
Visit this group at https://groups.google.com/group/Online_Sadhu_Sanga.
To view this discussion on the web visit https://groups.google.com/d/msgid/Online_Sadhu_Sanga/7ED20020-57DB-4328-B8E8-44A170AA5AF0%40ucl.ac.uk.
For more options, visit https://groups.google.com/d/optout.
Dear Umaji,
No. I will be nice if you can summarize his findings.
Best regards
kashyap
To view this discussion on the web visit https://groups.google.com/d/msgid/Online_Sadhu_Sanga/4607E4A3-558A-4347-90C8-54B7BCA83D5A%40gmail.com.
--
----------------------------
Fifth International Conference
Science and Scientist - 2017
August 18—19, 2017
Nepal Pragya Pratisthan, Kathmandu, Nepal
http://scsiscs.org/conference/scienceandscientist/2017
Send a Donation to Support Our Services: http://scienceandscientist.org/donate
(All Indian residents are eligible for tax benefits for their contributions under section 80G of the Income Tax Act)
Report Archives: http://bviscs.org/reports
Why Biology is Beyond Physical Sciences?: http://dx.doi.org/10.5923/j.als.20160601.03
Life and consciousness – The Vedāntic view: http://dx.doi.org/10.1080/19420889.2015.1085138
Harmonizer: http://scienceandscientist.org/harmonizer
Darwin Under Siege: http://scienceandscientist.org/Darwin
Princeton Bhakti Vedanta Institute: http://bviscs.org
Sri Chaitanya Saraswat Institute: http://scsiscs.org
Sadhu-Sanga Blog: http://mahaprabhu.net/satsanga
Contact Us: http://scsiscs.org/contact
---
You received this message because you are subscribed to the Google Groups "Sadhu-Sanga Under the holy association of Spd. B.M. Puri Maharaja, Ph.D." group.
To unsubscribe from this group and stop receiving emails from it, send an email to Online_Sadhu_Sa...@googlegroups.com.
To post to this group, send email to Online_Sa...@googlegroups.com.
Visit this group at https://groups.google.com/group/Online_Sadhu_Sanga.
To view this discussion on the web visit https://groups.google.com/d/msgid/Online_Sadhu_Sanga/CACLqmgfV%3D2ZZssRs4BtyWc9%2B1o886a_qZf1jgPnCBjdz7Ga6Rg%40mail.gmail.com.
Dear Paul,The fact that renormalisation is mathematically well defined does not seem to me to alter the fact that if a theory that posits a point particle in order to satisfy some intuitive sense of realism
On May 31, 2017, at 5:50 PM, Paul Werbos <paul....@gmail.com> wrote:Good evening, Jonathan!On Wed, May 31, 2017 at 1:09 PM, Edwards, Jonathan <jo.ed...@ucl.ac.uk> wrote:
Dear Paul,The fact that renormalisation is mathematically well defined does not seem to me to alter the fact that if a theory that posits a point particle in order to satisfy some intuitive sense of realism
Is QED consistent?
Quantum electrodynamics (QED) gives the most accurate predictions quantum physics currently has to offer.
The anomalous magnetic dipole moment matches the experimental data to 12 significant digits:
In spite of these successes of QED, many physicists think that QED cannot be a consistent theory. There is a phenomenon called the Landau pole: It indicates that at extremely large energies (far beyond the range of physical validity of QED, even far beyond the Planck energy) something might go wrong with QED. (QED loses its validity already at energies of about 10^11 eV, where the weak interaction becomes essential. The Planck energy at about 10^28 eV is the limit where some current theories try to make predictions. But the Landau pole, if it exists, has an energy far larger than the latter.) This is probably why Yang-Mills and not quantum electrodynamics was chosen as the model theory for the millenium prize.
Since the existence of the Landau pole is confirmed only in low order perturbation theory and in lattice calculations,
The quality of the computed approximations to QED are a strong indication that there should be a consistent mathematical foundation (for not too high energies), although it hasn't been found yet. There is no indication at all that at the energies where QED suffices to describe our world (with electrons and nuclei considered as elementary particles), it should be inconsistent. To show this rigorously, or to disprove therefore remains another unsolved (and for physics more important) problem.
Perturbative QED is only a rudimentary version of the 'real QED'. This can be seen from the fact that Scharf's results on the external field case
The quest for the 'existence' of QED is the quest for a framework where the formulas make sense nonperturbatively, and where the power series in alpha is a Taylor expansion of a (presumably nonanalytic) function of alpha that is mathematically well-defined for alpha around 1/137 and not too high energy. This is still open.
More precisely: Probably QED (and thus the QED S-matrix exists nonperturbatively as a 2-parameter theory depending on the fine structure constant alpha and the electron mass m_e; these parameters are the zero energy limits of the corresponding renormalized running coupling constants, and is defined for alpha <= 1/137 and input energies <= some number E_limit(alpha,m_e) larger than the physical validity of pure QED. What is needed is a mathematical proof that the QED S-matrix exists for 0<1 137="" (rather="" than="" only="" for="" infinitesimal="" alpha,="" as="" currently="" established)="" a="" unitary="" operator="" s(alpha)="" in="" the="" hilbert="" space="" h(emax)="" of="" all="" in-states="" energy="" <="E_max=E_limit(alpha)," some="" reasonable="" emax.="" <1>
We know from perturbation theory how to compute in such a range the coefficients of an asymptotic series in alpha for S(alpha). We also have a number of nonperturbative approximation schemes that give certain nonperturbative results (such as the Lamb shift).
But we currently do not have a way to ascertain that some well-defined object S(alpha) exists that has this asymptotic series. The quest for proving that QED exists is that of finding a construction for S(alpha) that makes rigorous sense and has the known asymptotic expansion.
QED is renormalizable at all loops, which means that the power series expansion of the S-matrix is mathematically well-defined at ordinary energies. The _only_ thing that is missing is to give its limit a mathematically well-defined meaning. Note that the S-matrix S commutes with the Hamiltonian; hence if P is the orthogonal projector to the space H_limit of states involving only energies < E_limit(alpha) then PSP is unitary on H_limit, and my conjecture is that PSP has some (yet unknown but) rigorous nonperturbative construction.
The Landau pole (if it exists) just gives an upper bound to the allowed energies. E_limit(alpha) is a function of alpha, which according to perturbation theory has to satisfy
To summarize:
QED is renormalizable at all loops, which means that the power series expansion of the S-matrix is mathematically well-defined at ordinary energies. The _only_ thing that is missing is to give its limit a mathematically well-defined meaning derived from a formulation of QED that makes sense also at finite times and not only as a transition from t=-infinity to t=+infinity.
https://www.mat.univie.ac.at/~neum/physfaq/topics/consistentQED.html