5 ms·
Special relativity. If you measure time in seconds, and speed in units of C, then vx^2+vy^2+vz^2+vt^2 is always a constant (in flat spacetime). So you have no
by altrego99 13y ago
Special relativity.
If you measure time in seconds, and speed in units of C, then vx^2+vy^2+vz^2+vt^2 is always a constant (in flat spacetime). So you have no choice over the matter. If you are stationary, time passes at a rate of 1 second / stationary second. If you move in space, rate of passage changes exactly by the amount required to compensate. So in a way, you always move at the same speed through spacetime, speed of light, and can only choose the direction.
The reason is that time dilation factor is the lorenz factor, (1-u^2/c^2). This is how much time will pass in your watch per one second of a stationary clock.
http://en.wikipedia.org/wiki/Four-velocity http://en.wikipedia.org/wiki/Four-velocity
- ars 13y agoJust remember that this is true only in special relativity. It is NOT true in general relativity, which means it's true only as an idea to understand things - the real universe does not follow that equation.
- darkmighty 13y agoIt does, locally.
- ars 13y agoNot under the influence of gravity it doesn't. Gravity causes time dilation without a corresponding velocity.
- tfgg 13y agoYes it does. Gravity changes spacetime, so the locally flat spacetime at the bottom of a gravity well isn't the same as the locally flat spacetime at the top of a well, but it's still flat in both cases.
- ars 13y agoHow does that cause a change in velocity? Or are you implying there is no time dilation?
- tfgg 13y agoIt's actually vx^2 + vy^2 + vz^2 - vt^2 the minus sign in front of the vt is very important and gives the SR (hyperbolic) structure of flat spacetime. The rotating a vector thing is just an analogy to euclidean space rotations.