Re: opposite of relativistic time contraction

On 2008-03-17, Erik Max Francis <max@[EMAIL PROTECTED]
> wrote:
> Not according to every source I could find.  Gravitational time dilation

> for an object in a circular orbit in a Schwarzschild geometry is
> 	tau'/tau = (1 - R/r)^(1/2),

That is the time dilation for hovering at a given distance, not
orbiting.  The time dilation for orbiting bodies should be almost as
simple (if I didn't mess up the geodesic equation math):

 ds/dt = (1 - (3/2) (R / r))^(1/2).


> Orbits by massive particles are unstable within the photon sphere
> (r = (3/2) R),

Given that the photon sphere is the radius at which the proper time
experienced by the particle around its orbit is zero, I would have
thought this made it intuitive that the time dilation in orbit would
be unbounded as your orbital radius approaches the photon sphere.


- Tim