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Relativity conundrum



The analysis of the following situation may prove instructive. The person on
the train measures the speed of light by sending the beam crosswise - from one
side to a mirror on the other etc. There are two possibilities:

1. The person DOES NOT KNOW that the train is moving with a speed v with
respect to the railway. So he/she obtains c' = x'/t, where x' is the distance
between the sides of the train and t is the time measured.

2. The person KNOWS that the train is moving with a speed v with respect to the
railway and accordingly determines the "real" distance x the beam has gone
through:

x^2 = (x')^2 + (vt)^2

Eventually he/she calculates the "real" speed of light:

c = x/t = gamma.c'

where gamma = [1 - (v/c)^2]^(-1/2)

What could be the implications of this result?

Pentcho Valev