Speed of Light/Gravity

Bill Payne (bpayne@voyageronline.net)
Mon, 27 Apr 1998 23:03:42 -0600

27 Apr 1998 20:40:26 -0500, Glenn R. Morton wrote:

> Nothing
> travels faster than light and to travel 1000 light years in one year would
> violate the speed of light.

I'm only going to respond to this one point in Glenn's excellent post.

I understand that gravity travels much faster that light, almost
instantaneously. If it did not, then the planets would be unstable in
their orbits.

I think it works like this. When sitting still in a car while it is
raining, you can see the rain outside falling vertically down. When you
begin to move, the rainfall appears to slant back. Likewise, because
the earth is orbiting the sun, the light rays from the sun slant in the
direction of the earth's travel relative to the sun, and the sun's disk,
as observed from the earth, is the sun's apparent position, not it's
true position. During a total solar eclipse, the moment of totality
comes either before or after (I can't remember which) the gravational
maximum exerted on the earth by the sun and moon combined.

Hopefully someone else can shed more light on this, the speed of
gravity.

Bill