It pains me to even type these out. I realize how many threads there are with very similar questions and to someone well versed in these topics, these questions probably all seem the same. But after reading what seems like all the questions, I feel I'm still confused. 1) In regards to the light clock experiment (and this may be more a classical physics question as opposed to a special relativity question). Due to the extended path (the 'c' in pythagorean's theorem) a light particle takes when traveling between a couple of mirrors at relativistic speeds, time must slow since light has a longer path to follow. The question then, is why is the light particle even following the path of the mirror? Why isn't it reflected perpendicular to the mirror and the other mirror moves out of the way by the time the particle reaches the opposite one (or at least the particle is off-center)? Thus rendering this experiment irrelevant? 2) Hitting on the twin paradox here. Before I begin, any speeds/velocities listed here are using Bill as the inertial frame. So... Jebediah and Bill are at Cape Canaveral. Jebediah on a rocket and Bill at Mission Control (We're pretending there is one at the Cape still). Jebediah takes off in his super-fast in his rocket and hits .5c. Bill see's Jebediah's Rolex (Bill is straight up eagle eye status here,people) ticking slower (this is conceptual folks, I don't care at this point about the Lorentz factor for exact numbers) than his own. Jebediah reaches uh... wherever. Betelgeuse and turns around. Now he's headed back at .5c. This is where I am confused. Since he is still going .5c (wrt Bill ) his Rolex is still ticking in slow motion, correct? And Jebediah still see's Bill's Rolex (yes he's been watching this whole time, the wonders of auto-pilot... or mechjeb for those of you who already caught on to my reference here) ticking slow since Bill is moving at .5c relative to Jebediah. Now most explanations I've read involve invoking acceleration (i.e. General Relativity, right?) or like, Doppler Shift or something. How does one reconcile this using JUST special relativity? 3) Length Contraction. The book I'm reading "How to teach your dog relativity" talks about a dog running along a steel barred fence at relativistic speeds. Bob, watching the dog, see's the dog contract some length to be able to fit between the bars of the fence. The dog, however, see's the bars of the fence shrink together some distance (again, not interested in numbers here, just the concept). The dog see's that he would be unable to fit through the fence if he were to change direction a bit. However the outside observer (in the same reference frame as the fence) see's the dog easily able to fit in the fence. So what if this outside observer pushed the dog through the fence? According to the outside observer the dog would fit, however from the dog's reference frame he would hit the fence. I'm clearly missing something here. I've got plenty more questions, but I'll leave it at this for now because A) These might answer a number of the rest of my questions, and B) My blood pressure is through the roof after becoming so frustrated by this. And lastly, I hope these all made sense, I just got off work and its 0345.