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 Be the first pioneers to continue the Astronomy Discussions at our new Astronomy meeting place...The Space and Astronomy Agora Re: Re: Re: About The Speed Of Light Forum List | Follow Ups | Post Message | Back to Thread Topics | In Response ToPosted by Jim Bergquist on January 1, 2001 03:44:04 UTC

I'll try to answer if you'll bear with me.

You say "But if the speed of a particle crossing the event horizon is c, then its mass should be inifite and its size sould be 0".

I think that what is important here is that the velocity c at the event horizon is a relative velocity--relative to a remote observer at rest. To the distant observer the robot probe's mass would appear to be infinite and it's velocity would appear to be c. There would appear to be no acceleration and velocity would appear to be constant. The robot probe would also notice that it's velocity relative to distant objects was c. Relative to the probe's local neighborhood its velocity would appear to be zero. Everything around it would appear to be dragged into the blackhole at approximately the same speed. There are tidal forces acting on nearby object which would tend to separate them along the line linking them to the blackhole. So to the probe, the object close to it may appear to accelerate.

At the event horizon contact is lost with remote objects. This is in a way similar to the loss of direct contact with locations beyond the horizon on the earth. But loss of contact does not necessarily mean that the object ceases to exist. The solution is to use a relay station to maintain contact. This assumes that the speed of light is just a communications barrier. This is the experiment that would have to be done to answer the question conclusively.