Help! Can anyone explain to me the "why" behind special relativity?

Question

Ok, I get it. I've seen the twin paradox, I've seen the ladder paradox, I know how to calculate time dilation and contraction and composition of velocities, etc. etc. But a few hours ago the question again popped into my mind: why does special relativity happen?

I'm sure it has something to do with the speed of light being constant, but my head's been spinning for hours and I can't figure it out. Can someone sum it up for me or at least put me on the right track?

Answer 1

Yes, the reason Special Relativity exists at all is because the speed of light is FINITE and constant.

Remember, we are basically trying to figure out how to relate velocity, distance, and time. If we assume that there is no speed limit,and objects can travel infinitely fast, then Special Relativity goes away, and we get plain Newtonian physics.

Answer 2

Yes it does have to do with the speed of light being the same for all observers regardless of the observer's velocities. However, the real compelling force in the development of the theory was the fact that maxwell's equations did not satisfy the principle of relativity, which is that all observers moving at uniform velocity (Galilean reference) experience the same physical laws. The maxwell's equations of electromagnetism are not invariant with respect to linear velocity transformation. Lorentz developed equations which would "make" maxwell's equations invariant, but they were not considered a physical reality until Einstein's theory. Unlike Lorentz, Einstein derived his transformations by assuming the invariance of the speed of light. The speed of light is derived from maxwells equations, so this derivation resulted in the same formulas as Lorentz's but based on direct physical evidence.

Interestingly, Lorentz's derivation involves several pages of very complex mathematics, but Einsteins is done on one page using algebra only.

Answer 3

I like to think of this as the Matrix "bullet time." Space has 4 dimensions. The 3 physical dimensions and time. As you move more quickly in a single dimension you travel less quickly in the others. If you travel near the speed of light you are almost not moving in the other dimensions at all. Because of this time slows for you. Because of this you have the "bullet time" effect. While you move in slow motion light is only passing by you a fraction faster. If a camera was flying next to you and was not affected by slowing of time it would actually see light moving slow and you moving very very slow. Relate this to the "bullet time" and it makes perfect sense. Neo, who is in the moment sees the bullets whiz past him at full speed. But to us who are looking at him in bullet time the bullets are moving slow and he is moving very slow. It sounds like you have done way more than I in this subject but I always found the bullet time analogy to help.

Answer 4

because the speed of light is constant, you could never go faster than light, when you get close to the speed of light time slows down to make sure of the fact that you can't go above the speed of light. so the time itself acts as a gurantee that speed of light is a threshold.