From: eric@flesch.org (Eric Flesch) Subject: Re: Photons and gravity Date: 1998/05/22 Message-ID: <35664be7.51046122@news.nn.iconz.co.nz>#1/1 Content-Transfer-Encoding: 7bit References: <6jvrq5$b93$1@supernews.com> <6k1gs2$nbt@darkstar.ucsc.edu> <6k1hnu$k31$1@jelerak.scrye.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Organization: Internet Company of New Zealand Newsgroups: sci.physics On Fri, 22 May 1998 02:07:58 -0700, C. Hillman wrote: >Now, a single isolated wave pulse, much less a single photon, won't cause >much of a gravitational field. (...) >However, it -is- possible to obtain an exact solution of the >Einstein-Maxwell equation... (...) >the work of the quantum gravity folk >may yet introduce new romance :-/ into this so far uneasy relationship). This was a well-considered and well-phrased posting. What Chris is saying is that GTR provides well-defined gravitational solutions to the image of a photon propagating through space. The fly in the ointment is that this image (of a photon propagating through space) is certainly wrong. The delayed-choice experiment proves that the "travelling photon" exists at no point in space. The photoelectric effect shows that photons are particles. The Schroedinger equations model the propagation of probabilities, not particles. Thus it is shown that photons, as particles, exist only at the endpoints of the path, i.e. at emission and absorption. In between there is no classical particle, nor any classical wave. What does not exist cannot gravitate. So, GTR is correct. *Were* there photons propagating through space, they would certainly follow the GR dynamic. But GR is not a theory of light, and the travelling photons are not there, so no stress-tensor, and no gravitation. C'est la vie. And there is the new romance which Chris speaks of. Eric Flesch