Chronology Current Month Current Thread Current Date
[Year List] [Month List (current year)] [Date Index] [Thread Index] [Thread Prev] [Thread Next] [Date Prev] [Date Next]

Re: Variable speed of light (was: Relativity conundrum)



Pentcho Valev wrote:


There is a version which could be a thought experiment and which unequivocally
shows that the speed of light is not constant. In the rest (railway) frame the
beam approaches the train at a right angle so that, in the train frame, it moves
obliquely. Consider two events - the beam entering the train and the beam
leaving the train - registered in both frames. Obviously x < x', where x is the
distance the beam travels between the two events in the rest frame and x' is the
respective distance in the moving frame. The time measured in the rest frame for
the travel x is t, and that measured in the moving frame for the travel x' is
t'. If there is time dilation, t' < t and, accordingly,

c = x/t < x'/t' = c'


Just for the sake of the argument, assume that the numerical value of the speed of
light is the same in the two frames. then, in the frame where the light moves
obliquely, the light must travel a longer distance, x', and hence must take a
proportionately longer time, t', to travel that longer distance. The ratio x'/t'
would therefore remain the same as x/t (because x' > x and t' > t). Time dilation
really is not a consideration here, and t' is definitely not less than t. Even if
time dilation was applied (which would also require considering a length contraction
of the component of obliqueness parallel to the train's motion), t' > t still holds.

Your assumption of t' < t is what's leading to the differing values for c and c'.

Bob at PC