Tim Bates wrote:
> Josef 'Jupp' Schugt wrote:
> 
>> Superluminal speed ist nothing that requires a hyperspace. The 
>> relative speed of galaxies for example is known to exceed the speed of 
>> light.
> 
> 
> No, it's not. You've forgotten your elementary relativity. If you have 
> two galaxies on opposite sides of the universe (call them A and B) with 
> an observer in between (called O) then from O's frame of reference the 
> sum of the speeds of A and B might exceed c (the speed of light), 
> although neither galaxy's individual speed can exceed c, BUT from A's 
> frame of reference B's speed does not exceed c and vice versa.
> 
> If this sounds bizarre and impossible to you, you haven't studied physics.

I think he's misunderstanding certain observations that seem to indicate
superluminal velocities. I forget exactly how it works, but it's essentially
an optical illusion. Something about making the (invalid) assumption that
light from both ends of a jet left at the same time.


Hal