Article View: sci.physics
Article #16169Re: Why does light bend under gravity?
From: BradGuth
Date: Sun, 30 Mar 2008 03:38
Date: Sun, 30 Mar 2008 03:38
91 lines
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6511 bytes
On Mar 16, 4:39 pm, The Speaking Clock <harlequin...@live.co.uk> wrote: > On 17 Mar, 01:04, BradGuth <bradg...@gmail.com> wrote: > > > > > On Mar 16, 1:41 pm, The Speaking Clock <harlequin...@live.co.uk> > > wrote: > > > > On 16 Mar, 20:30, BradGuth <bradg...@gmail.com> wrote: > > > > > On Mar 16, 9:14 am, Tom Roberts <tjroberts...@sbcglobal.net> wrote: > > > > > > The Speaking Clock wrote: > > > > > > On 15 Mar, 08:57, Pentcho Valev <pva...@yahoo.com> wrote: > > > > > >> [... his usual nonsense] > > > > > > > Would the speed of light be a non wiggly constant at the very edge of > > > > > > the universe - bending around it? > > > > > > The speed of light is a constant, c, for any LOCAL measurement anywhere > > > > > in the universe. I guess that includes "non wiggly". It also includes > > > > > essentially all measurements of light speed here on earth. At least that > > > > > is what GR predicts, and there are no observations that contradict it. > > > > > > [Ignore Valev when he brings up Pound-Rebka and similar > > > > > experiments -- they do not measure speed.] > > > > > > But if you want to see light "bending around the universe" then that > > > > > would certainly require a non-local path, and there's no solid > > > > > prediction of the result (given the uncertainties in the physical > > > > > situation you have in mind). > > > > > > It is rather difficult to perform a non-local measurement of the speed > > > > > of light, but it has been done by sending radar waves across the solar > > > > > system to reflect back from mars and venus. By measuring the round-trip > > > > > delay repeatedly over several years, and fitting to the planetary > > > > > orbits, one can deduce the round-trip speed of light for these paths. > > > > > That speed varies, depending on how close to the sun the path passes; > > > > > look up "Shapiro time delay". The results are in excellent agreement > > > > > with the predictions of GR. > > > > > > Some people claim this is due to the solar atmosphere. > > > > > They are wrong: by doing this for multiple wavelengths the > > > > > effect of the solar atmosphere can be identified, and is > > > > > found to be negligible. Of course it would be highly > > > > > unlikely that such a different effect could mimic the GR > > > > > dependence on path. Indeed, measurements using pulsars > > > > > agree with the GR predictions for paths that never go > > > > > inside earth's orbit, and we know what the solar > > > > > atmosphere is out here. > > > > > > Tom Roberts > > > > > But photons clearly represent mass, thus the solar atmosphere of > > > > photons does offer mass for other passing photons to interact with. > > > > . -BradGuth- Hide quoted text - > > > > > - Show quoted text - > > > > My physics friend says - "what about the underlying noise of the > > > universe caused by the discrete nature of the photon/s in time, and > > > how does that contribute to the total 1/f energy of the universe?" > > > > And then he changed the subject because light speed and it's constant > > > interacting with what he talked about is something to do with space > > > travel and I'm a buddhist. lol. Although - this is just my surmise;) > > > Don't exclude anything unless you know for certain otherwise. > > . - Brad Guth- Hide quoted text - > > > - Show quoted text - > > *nodding like the churchill dog* > > My physics friend also says that photons have a *theoretical* mass. > Whatever that means. To a buddhist - everything looks largely > theoretical. :) > > Physists don't agree on anything - not the shape of the universe, > whether light has a constant, why it bends. Ask a simple question - > get a complex argument. Ah well - as long as people have fun. :) This anti-think-tank of a Usenet from hell is a good example, of supposedly smart folks not hardly in agreement on much of anything, especially if such rocks their mainstream status quo good ship LOLLIPOP. I like the zero-mass dump-truck as representing a photon, that which can haul a wee bit of mass. . - Brad Guth
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X-Google-Thread: 10b271,1ea0cb1d54d3d906 X-Google-Thread: 10f545,2d47498f99950055 X-Google-Thread: f6c41,2d47498f99950055 X-Google-Thread: fa4c1,c0039b44052ddae9 X-Google-Thread: f74ae,c0039b44052ddae9 X-Google-Attributes: gid10b271,gid10f545,gidf6c41,gidfa4c1,gidf74ae,domainid0,public,usenet X-Google-Language: ENGLISH,ASCII-7-bit Path: arc1-ca.pugleaf.net!g2news1.google.com!postnews.google.com!d4g2000prg.googlegroups.com!not-for-mail From: BradGuth <bradguth@gmail.com> Newsgroups: sci.physics,sci.physics.relativity,sci.physics.particle,fr.sci.physique,sci.astro Subject: Re: Why does light bend under gravity? Date: Sat, 29 Mar 2008 20:38:19 -0700 (PDT) Organization: http://groups.google.com Lines: 91 Message-ID: <fc243153-99b6-4ca4-8ab6-a9e4779a12b3@d4g2000prg.googlegroups.com> References: <1de25376-cbdf-4a88-9c24-635b73e962f0@e60g2000hsh.googlegroups.com> <5d081222-5b36-4e82-b8d7-8900c2acbbc4@d4g2000prg.googlegroups.com> <L_mBj.16850$Ch6.2540@newssvr11.news.prodigy.net> <4a84042b-1718-45a4-82f9-0e2b9fa12240@x41g2000hsb.googlegroups.com> <toRBj.16222$xq2.10827@newssvr21.news.prodigy.net> <a2ca4f30-9c55-4fa6-a0a1-cc7ad49e36a4@s37g2000prg.googlegroups.com> <e2b37da4-49a5-40da-95d8-c48add78539d@8g2000hse.googlegroups.com> <350f08c0-cbc4-43ca-9ece-629159f22125@h11g2000prf.googlegroups.com> <OzcDj.20839$Ej5.5102@newssvr29.news.prodigy.net> <35e2ae0d-b9b5-4f10-9dc2-b2cccd1bdf17@s12g2000prg.googlegroups.com> <7dc131af-610a-486d-9b23-05fc2664b58a@e23g2000prf.googlegroups.com> <7e1f59da-1eb6-4d06-9fb5-f520de683fdc@s8g2000prg.googlegroups.com> <5765550f-de11-49b8-9e4e-2bd424d5768b@s19g2000prg.googlegroups.com> NNTP-Posting-Host: 64.91.99.82 Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-Trace: posting.google.com 1206848299 14641 127.0.0.1 (30 Mar 2008 03:38:19 GMT) X-Complaints-To: groups-abuse@google.com NNTP-Posting-Date: Sun, 30 Mar 2008 03:38:19 +0000 (UTC) Complaints-To: groups-abuse@google.com Injection-Info: d4g2000prg.googlegroups.com; posting-host=64.91.99.82; posting-account=nf79RwoAAABXjvy5ztMzmPxgY1WGoktI User-Agent: G2/1.0 X-HTTP-UserAgent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.1.12) Gecko/20080201 Firefox/2.0.0.12,gzip(gfe),gzip(gfe)