Admittingly this seems rather simple to be a real problem with the theory so there is problably something I’m not understanding. However I’m very interested on how to overcome this paradox. So here goes.
It involves 4 observers A1, A2 (not moving wrt each other) in inertial reference frame A; B1, B2 (not moving wrt each other) in ref B; and a light flash source in space. A1, A2, B1, B2 have synchronized clocks.
A1 is situated at the light source and is not moving wrt the light source, A2 is a far distance away. The flash goes off at exactly t=0 On A1’s clock. The light reaches A2 at exactly t=6000 hours on his clock. Simply enough.
B1 and B2 are always located on the same line that A1 and A2 are on. B2 is moving toward the light source. B1, B2 are moving 50km/h wrt to A1,A2 such that B1 is coinciding with A1(and the source) at t=0, and B2 is coinciding with A2 when the light reaches A2.
So from the info above: when the flash goes off at t=0, B2 is 300,000km further away from the source than A2 is. The question is what time is it on B2’s clock when the flash hits him???
Just looking at ref frame B’s perspective the light should take 6000 hours and 1 second to reach B2 since the distance is 300,000km longer than A1 to A2.
However the light hits A2 and B2 in the same spot and same instant. B2’s clock is synchronized with A2’s. So how can they have a different reading???
I am only considering invariant speed of light here. Time dialation and length contraction are negligible at these speeds. And I don’t see a problem with synchronizing clocks at these speeds.