This is a facinating topic isn't it guys?
TR3 has already mentioned time dilation, well try to get your heads round this one... length contraction - If L0 is the distance between two points that are at rest in a particular frame of reference L0 is called the proper length. If this frame moves with constant speed u relative to a second frame and the distances are measured parrallel to the motion, the distance L between the points as measured in the second frame is
L=L0root(1-sq(u/c))
So if our aeroplane could travel at c its length would become zero. And I have stated in a previous post that its mass would become infinite. So that means that our aeroplane would become infinitely dense- a singularity if you will. And you know what that means don't you? A black hole.
AA I guess that the actual speed of the beam within a medium remains c. I account for the apparent slowing of the speed of the light in that the distance travelled by the light in a medium is increased as a result of reflections off molecules of the medium. The general direction of the beam remains the same within the medium. Note that the spaces between the molecules are vacuum.
[ 29 July 2001: Message edited by: Harry999 ]