On 6 mar, 21:20, "Sue..." wrote:
On Mar 6, 3:41 pm, Albertito wrote:

There are evidences showing that in Solar system,
the speed of gravity is many orders of magnitude higher
than the speed of light.

There is evidence of that when you push a car.
It pushes back instantly. But that doesn't
mean gravity moves faster than c.

The finite speed of light is in evidence
as the car begins to move forward and the
remainder of the universe shifts position just a bit
to make room for the car's field from
a new position. That realignment propagates
at less than c.

But, what must we understand
by speed of gravity?.

See above:

I can't find a source or destination in
your equations. I can with Koroupolis
and the light paths are identified.

http://arxiv.org/abs/physics/0107015

[...]

Can't you find a source or destination in my equations?
It is easy to find. If you can find the source and destination
for electromagnetic waves, then you can for gravitational
waves, too, because the source is the same and so is
the destination. The difference is that there is a pair of
events, S_e and S_g. The electromagnetic event S_e
is delayed and the gravitational event is advanced, they
are not simultaneous events at the receiver. If you are
able to detect a gravitational wave at time t_0, then you
should be able to detect the associated electromagnetic
wave at time t_1 t_0. If the difference (t_1 - t_0) is very
large, say of some centuries, you will be in serious troubles
to find the source. This is the issue that might be happening
with distant astronomical objects: a great observed shift
between gravitational an electromagnetic events.