Couple days ago, we get a lecture in relativity, I read quite a lot about it before so there was nothing new except one thing : our professor first started to conclude Lorentz transformation totally in a mathematical way by assuming gamma*(x-v*t) … (what I discovered that it is a known method but somehow I didn't read about before) Anyway during the formulation of Lorentz transformations, we proving that (1-gamma^2)/v^2=constant (which is actually 1/c^2) , this conclusion stopped me a lot, and I searched Internet for couple days to get an answer to may question in vain: from purely mathematical point of view , not speaking about Einstein relativity nor speed of light, what that means!? If I will have a question of calculating when some even accrue in another reference frame in some totally abstract space-time like Euclidean space, what this constant will mean? We can't say it is max allowed speed in this abstract 2D plane! Because there is not any, and saying put it simply to zero also not quite acceptable from pure math point of view, because we have to prove it! Actually it's very important question to me, and I can't accept mathematically just to put it zero to get Galilean transformation, hope that somebody has a clue how to understand this! Thanks in advance.