Moderator note: This thread has been split from the following thread: [thread=101005]A thread about Jack's capacity to discuss relativity[/thread] Please use the current thread only to discuss Jack_'s issues with time in relativity, and not for character analysis. Thankyou. --- Jack, there are a few problems with this question. You'll need to be more precise. Firstly, a semantic issue. A reference frame doesn't "see" anything. Do you mean to ask when measurements made in the moving reference frame indicate that...? Secondly, the question is loaded with the assumption of absolute simultaneity. It assumes that a particular instant ("when") in one reference frame universally translates to a single instant in another reference frame. It is clear that you simply do not understand what SR says about how time transforms between reference frames. You can learn, Jack, it's really not that difficult. Briefly: The light reaches a distance r in the moving frame at a time t'=r/c after it is emitted. That moving frame instant, when t'=r/c, does not happen at one instant in the stationary frame, but over a period of time. But, this has already been explained to you, patiently and repeatedly. I fully expect that you will just ignore it once again and repeat your same old boring story. Surprise me, Jack. Take off that steel skullcap and consider a new idea. You don't need to accept it, but we do expect you to honestly consider it. That's how we learn.