Re: [Phys-L] foundations of physics: Galilean relativity

[Jeffrey Schnick <JSchnick@Anselm.Edu>]

After one second the photon is already so far away from the planet (about 300 000 km) that the component of the acceleration due to the gravity of the planet, in the original downward direction, at the location of the photon, is much smaller than g, the nearly constant acceleration experienced by the positronium during the first ten seconds.
________________________________________
From: Phys-l [phys-l-bounces@www.phys-l.org] on behalf of John Denker [jsd@av8n.com]
Sent: Sunday, October 04, 2015 7:09 PM
To: Phys-L@Phys-L.org
Subject: Re: [Phys-L] foundations of physics: Galilean relativity

On 10/04/2015 02:11 PM, Jeffrey Schnick wrote:

> I estimate that for a planet like Mercury, after 10 seconds, the
> positronium would fall about about 185 meters below the drop point

So far so good....

> whereas the center of mass of the two-photon system would fall about
> .6 meters.

Huh?  Whatever happened to the equivalence principle?

> I don't know how to do the calculation using general relativity so I
> used double a classical estimate.

The only calculations I know how to do, classical or otherwise,
uphold the principle of equivalence.  The photons drop at the
same rate as everything else.

This has been checked experimentally to very high accuracy ...
parts in 10^12 the last time I checked, although there were
plans afoot to do even better.........
_______________________________________________
Forum for Physics Educators
Phys-l@www.phys-l.org
http://www.phys-l.org/mailman/listinfo/phys-l