Then you accept that if 3E8 markers pass by in 0.577 seconds with a speed of 0.866c then there's half a meter between them. Good for you. Well, either that or contracted meters. Here's the thing: I agree with you that the ship and the markers pass each other by at a rate of 5.196E8 markers pr. ship second. However, that does not translate to a velocity of 1.732c, because the dimensions are wrong. You've already agreed that the meters and times have to come from the same frame. So what you are assuming is that the 1 one earth meter between the markers translates to 1 ship meter. But that's what you were supposed to convince us of! And in fact, it's blindingly obvious from the example that it's wrong! Length contraction merely states that length in the moving frame (i.e. the spacing between the markers) appear contracted relative to lengths in the rest frame (the ruler on the spaceship), as viewed from the rest frame (i.e. to the man on the ship) Now, that is exactly what the example comes out wiith: 3E8 markers with a speed of 0.866c (in ship meters per ship second) passing by in 0.577 ship second, makes them out to be half a ship meter apart! I have addressed your scenario, and demonstrated that it leads to length contraction. The only way you can keep length contraction out is by redefining the concepts of distance, time, and velocity, and denying the relationship of d = vt between them. No dice. I will not allow you to change the rules to fit your whim. The man on the ship can measure the speed of the markers, he can measure the time it takes for them to pass him, and he can use that information to conclude that there's half a meter between them. He doesn't need to use any information from my frame at all, nor does time dilation come into it. Now answer the fucking questions. Are those measurement valid or not? But how can you ever measure that distance in space in the first place? Except, of course, that you deny that those standards. It's right there. "Length contraction is prohibited". What kind of argument is that against length contraction? Furthermore, you even acknowledge that you have to fundamentally redefine the concept of velocity (and thereby inevitably distance and time). Notwithstanding that, it begs the question of which frame's measure of distance one should use. It is obvious that if we measure thing in the usual way (that is, the non-MacM way), then the man on the ship will measure the distance between the markers to be half a meter. Now the distance between the markers is "really" measured to be 1 meter. However, that has to have been measured the in the Earth frame. How does the man on Earth know that his measure of a meter is a "true" measure of distance? He can't have used the MacM way of measuring distance: How on Earth (pun intended) would he know which measure to use? He has to assume that he is the one at rest, and that d=vt (where v is the velocity of things measured in the usual way) is actually true in his frame in order to elevate his measure of distance to the "true" measure. Otherwise, he has to tag all the distances as being "Earth measured distances", which begs the question of why Earth measurements are truer than ship measurements. The trip time of the moving observer is the accumulated time on his clock. Proper time is physical time. He does not need to account for time dilation. So that's a tentative no, because you haven't specified how the "accounting" is done. Length contraction, just as time dilation, follows directly from the isotropic propagation of light. You cannot have one without the other unless you break that isotropy. In which case you at the very least have to explain why experiments show that isotropy, and suggest a new experiment that can differentiate between your new theory and relativity theory. d=vt. If v is frame dependent then so is d. Please Register or Log in to view the hidden image! yourself.