Naeman

See now, this I could understand, except what about this Twin paradox thing? How does time determine which object is in fact the one that receives slower time?

Does anyone know? I can't find an answer that I can understand anywhere.

So then the reason that time goes slower for the ship's inertial frame is because its outside the "home ice" or the inertial frame for the rest of the universe that isn't moving, right? I think I get it now.

Okay, I think I understand most of what I asked. The only thing I don't get is why is a ship in uniform motion still going slower at that moment than the chose inertial frame? If it considers itself at rest since it is in uniform motion, why does the time dilation effect the ship and not the "planets" ? I think I'm just missing something, I guess what I'm wondering is what makes dilation apply to a ship thats not accelerating instead of the world outside of it. Is it because the ship is the one object that is moving in a different inertial frame than everything else?

Oh, I just remembered something from a long time ago when I first learned and actually understood relativity. I believe the theory was that the fastest way to get somewhere (least aging) was to accelerate to the halfway point then decelerate at the same rate. Does this mean that time dilation doesn't apply to uniform motion? If I missed that, that would explain why I didn't get it for so long. Also, the physical length of a trip seems smaller to a ship that is a victim of dilation if measured, right? My for real, actually-last question about special relativity (or the basis of it anyhow) is about length contraction. Again, I understand that it happens, just not exactly how. Again, thanks for listening, and thanks for the replies

Oh, I see now. I once saw an extremely complex version of the twin paradox explaining why my problem didn't happen before and after he accelerated, eliminating the problem that it wasn't constant. I didn't understand it, but it turned out that that it all balanced out in the end with the spaceship aging slower even though it started out faster or something....I don't know. This really answered my questions though, thanks.

Physics is a lot more interesting than I ever imagined it to be, at least the special relativity aspects of it. I have a couple of questions. I mostly understand the theory, but a few questions which I can't find an answer to (at least not translated into non-expert-physicist terms) have been bothering me. (I know, they're the really amateur questions that people who don't understand it well ask a lot but....) First of all, if there's a spaceship moving at .9c, then relativity tells us that time moves slower because its moving, I.E. the twin paradox. However, couldn't the spaceship consider itself at rest and everything else moving slower through time? What is it that determines that the spaceship is specially the moving object? Also, the question of C being the same to all observers bothers me. How can this be? I understand that C is the same to all observers, just not how. You've probably all heard the "what if I'm travelling in a rocket at 1/2c and I shine a light, wouldn't it be going 1 1/2c?" question, so thats basically what I'm wondering. Again, I know galilean velocity additions don't apply, but it doesn't seem to register why it wouldn't go 1 1/2c. Is it because it would need infinite acceleration to surpass the speed of light? Thanks for listening.