- #1

berlinspeed

- 26

- 4

- TL;DR Summary
- Need help on a simple 4-velocity components derivation.

Anyone know how to derive ##u^0=\frac {dt} {d\tau}=\frac {1} {\sqrt {1-\mathbf {v}^2}}## and ##u^j=\frac {dx^j} {d\tau}=\frac {v^j} {\sqrt {1-\mathbf{v}^2}}##?