Thank you,
This means (I think):
That I'd be right in saying
\frac{dt'}{d\tau} = \gamma_w
and \frac{dt}{d\tau} = \gamma_u
We know \frac{dt'}{dt} = \gamma_v (1-\textbf{u.v}/c^2)
and dt'/d\tau = \frac{dt'}{dt} \frac{dt}{d\tau}
Subbing in gives the desired result...
Homework Statement
Two particles have velocities u, v in some reference frame. The Lorentz factor for their relative velocity w is given by
\gamma(w)=\gamma(u) \gamma(v) (1-\textbf{u.v})
Prove this by using the following method:
In the given frame, the worldline of the first particle is X...