Here's a question that's bothered me for a while. Suppose you are a person (P) at point A. You travel between point A and B at some fraction of c (speed of light). And so relativity kicks in. Now, that's the standard relativity model and we talk about P with regard to A and B. Now, what if we extend the model. Let's suppose that A is Earth and B is Mars. Now, let's say there's some A' which contains both A and B. Let's also suppose there's some B' which contains C and D. Extending further, let's say there's som A'' which contains A', and A''' which contains A''. Also, B'' which contains B' and B''' which contains B'': A''':A'':A':A,B,P B''':B'':B':C,D Several questions come to mind: 1) The velocity of P between A and B can be seen differently depending on the frame of reference (A''' vs A'). However, as the velocity of P approaches c, it approaches c for all frames of reference, doesn't it? 2) Assuming that A', A'', and A''' have their own "group" velocity, that velocity must be additive to the velocity of P. For example, a person on a train at 60 MPH throws a ball at 10 MPH, from outside the train the ball is at 70 MPH. Assuming that question #1 is true, then if any "container" approaches c, then from frames of reference outside that container, P must be traveling at near c. But also, if #1 is true, then P must be traveling at something close to c WITHIN the local frame of reference, shouldn't it? 3) Since we can observe that P isn't traveling near c (because it doesn't have the appropriate characteristics), can we then infer that no container for P is traveling near c from any frame of reference? 4) And isn't all of the above true even from B', B'', and B'''?