Article View: sci.physics.relativity
Article #5565Re: LEE SMOLIN AGAINST ISAAC NEWTON
From: Rock Brentwood
Date: Sun, 10 Feb 2008 10:25
Date: Sun, 10 Feb 2008 10:25
25 lines
2915 bytes
2915 bytes
On Feb 6, 10:48 am, "Androcles" <Headmas...@Hogwarts.physics> wrote: > | Classical Newtonian mechanics predicts that light will bend with > | twice the angle observed. > > How? Good question. Actually, I think it's 1/2 the angle, not twice. To come up with refined tests for Newtonian vs. Relativistic gravity; it's common for people to embody the former in the framework of Newton- Cartan geometry. This minimizes the differences between the classical and relativistic theory (a necessity if you want to do experimental tests), down to their minimal core differences. Newton-Cartan gravity is a curved spacetime theory compatible with Newtonian physics and the Galilean symmetry group that presides over Newtonian physics. If you go with straight classical theory, treating Newtonian gravity as a field on top of a flat spacetime, then I think Smolin is right -- no bending of light. On the other hand, if you use the classical version of the Equivalence Principle, then that would imply light undergoes the same acceleration near a gravitating body as does everything else. Then, in effect, you're back to the curved spacetime form of Newtonian gravity -- that is, the same results follows ... a bending in Newtonian gravity at 1/2 the angle predicted by General Relativity.
Technical Details
Message-ID:
<d867a426-b0fa-46be-9192-69aa1364e40a@h11g2000prf.googlegroups.com>Path:
arc1-ca.pugleaf.net!g2news1.google.com!postnews.google.com!h11g2000prf.googlegroups.com!not-for-mailReferences:
<e3cb16d6-c73b-4e59-9f50-5cda6da5d475@m62g2000hsb.googlegroups.com> <4695358e-db97-4485-94b4-06f417a451d4@i7g2000prf.googlegroups.com> <9xlqj.57995$801.21058@fe1.news.blueyonder.co.uk>Show Full Headers
Complete Article Headers
X-Google-Thread: 10f545,89f2be10e566fb3e X-Google-Thread: 10b271,89f2be10e566fb3e X-Google-Thread: fa4c1,89f2be10e566fb3e X-Google-Thread: 1139f8,89f2be10e566fb3e X-Google-Thread: f55d3,89f2be10e566fb3e X-Google-Attributes: gid10f545,gid10b271,gidfa4c1,gid1139f8,gidf55d3,public,usenet X-Google-Language: ENGLISH,ASCII Path: arc1-ca.pugleaf.net!g2news1.google.com!postnews.google.com!h11g2000prf.googlegroups.com!not-for-mail From: Rock Brentwood <markwh04@yahoo.com> Newsgroups: sci.physics.relativity, sci.physics, fr.sci.physique, fr.sci.maths, fr.sci.philo Subject: Re: LEE SMOLIN AGAINST ISAAC NEWTON Date: Sun, 10 Feb 2008 02:25:55 -0800 (PST) Organization: http://groups.google.com Lines: 25 Message-ID: <d867a426-b0fa-46be-9192-69aa1364e40a@h11g2000prf.googlegroups.com> References: <e3cb16d6-c73b-4e59-9f50-5cda6da5d475@m62g2000hsb.googlegroups.com> <4695358e-db97-4485-94b4-06f417a451d4@i7g2000prf.googlegroups.com> <9xlqj.57995$801.21058@fe1.news.blueyonder.co.uk> NNTP-Posting-Host: 4.159.173.238 Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable X-Trace: posting.google.com 1202639155 31910 127.0.0.1 (10 Feb 2008 10:25:55 GMT) X-Complaints-To: groups-abuse@google.com NNTP-Posting-Date: Sun, 10 Feb 2008 10:25:55 +0000 (UTC) Complaints-To: groups-abuse@google.com Injection-Info: h11g2000prf.googlegroups.com; posting-host=4.159.173.238; posting-account=G-TjQAkAAADYg6rno3bWQPnIwKFBrf1t User-Agent: G2/1.0 X-HTTP-UserAgent: Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.1; .NET CLR 1.1.4322),gzip(gfe),gzip(gfe)