On 30-3-2010 20:29, Darren New wrote:
> andrel wrote:
>> hence my "We say that because we believe in Lorentz invariance" as a 
>> abbreviation of a couple of paragraphs like the one above ;)
> 
> Lorentz invariance would explain it if time was running slower or the 
> speed of light was different farther away as well.
> 

No, differential time- and lightspeeds are incompatible with lorentz 
invariance of physical laws, because they should be invariant under 
translation and uniform velocity changes.
In particular Maxwell's equations are lorentz invariant and they imply a 
*constant* velocity at which E and B fields propagate (generally known 
as c).

It might be possible to modify Maxwell's equations to allow timevarying 
lightspeed and find a new invariant that for times close to our own 
reduces to Lorentz invariance, but I have not heard of anybody doing 
that trick.

Post a reply to this message