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- From: sichase@csa3.lbl.gov (SCOTT I CHASE)
- Newsgroups: sci.physics
- Subject: Re: Defining Photons
- Date: 27 Jul 92 17:51:45 GMT
- Organization: Lawrence Berkeley Laboratory - Berkeley, CA, USA
- Lines: 42
- Distribution: na
- Message-ID: <24927@dog.ee.lbl.gov>
- References: <24910@dog.ee.lbl.gov> <9976@sun13.scri.fsu.edu> <26JUL199218561022@zeus.tamu.edu> <1992Jul27.033211.26912@Princeton.EDU>
- Reply-To: sichase@csa3.lbl.gov
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- Keywords: Relating photons E=MC^2 criticism
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-
- In article <1992Jul27.033211.26912@Princeton.EDU>, vgurarie@phoenix.Princeton.EDU (Victor V. Gurarie) writes...
- >
- > I have a strong feeling that one would NEVER be able to produce a
- >semiclassical state of W or Z particles. They are so massive that they
- >would decay BEFORE we could form a semiclassical state. Also their
- >characteristic length is R=1/M, M - mass.
-
- Whether we have the technology to do so or not is rather beside the point.
- In principle it *is* possible to produce enough of them in short enough
- a period of time to produce such a state. It just seems unlikely that anyone
- will apply for NSF funding to do so in the near future.
-
- And the "characteristic length" is not applicable here at all because we
- are talking about physical (on shell) W's. The relevant quantity is
- width, not mass (which is about 2.2 GeV instead of ~80 GeV - still a short
- lived system).
-
- > It is masslessness of the photon
- >which makes it behave like a wave. (and its stability). Anyway,
-
- Once again, this is completely false. Rather than repeat what I and several
- others have already explained, I suggest that any interested persons find
- J.J. Sakuri's Advanced Quantum Mechanics and study up a little on the
- semiclassical limits of quantum fields. (I am pretty sure Sakuri discusses
- the subject. If not, try Bjorken and Drell but beware that it is not for
- amateurs. I won't even mention Itzykson and Zuber!)
-
- You will find that serious attempts at quantizing photons in a rigorous way
- actually treat the photon as massive (to elimate certain problems which
- arise from gauge transformations) and then discard the unphysical part of the
- resultant fock-space which results from the unphysical degrees of freedom.
- (The phrase "Buela-Gupta quantization" pops into my head.) The massiveness
- in no way interferes with the photon's quantization or its behavior in the
- classical limit.
-
- -Scott
- --------------------
- Scott I. Chase "The question seems to be of such a character
- SICHASE@CSA2.LBL.GOV that if I should come to life after my death
- and some mathematician were to tell me that it
- had been definitely settled, I think I would
- immediately drop dead again." - Vandiver
-