🚀 go-pugleaf

My name is Kim Yong-jin, Korean graduate student majoring in Plasma Physics.

	You asked about the meaning of below eq.

		Tb - Ta = Ta' - Tb

We can make a Gedanken exp.
	1. Observer at A cite records time when the light emits from A by
    reading his Clock ---> Ta
	2. Observer at B cite records time when the light arrives at B which
    coincides with the time of immideate reflection of light by reading his 
    Clock ---> Tb
	3. Again, obs. A records his when light arrives at the spot just
    from which it emits.  -----> Ta'
	4. Now the Two observers come into contact in face to face or
    by any means and talk about their measurements , especially their
    time recordings, Ta, Tb and Ta'.
	
	Just after calculating the simple differences of two pair of times
    Tb - Ta and Ta' - Tb, the former for time of light flight from A to B,
    the latter for flight from B to A.  If they get the same values for
    two calculations and even believe homogeniety of the space for light flight
    , then they can get the conclusion that 
	" their clocks are synchronized "

	Here, I think, "the time of flight of light" is some kind of ideal
    thing, and if we keep in mind the fact that important thing is the
    quantity of measurement, we have no wondering of "time".

		Thanks.
			Bio Yong-jin.