Local radial speed of a Schwarzschild geodesic
= Local radial speed of a Schwarzschild geodesic
{title2=$v_{\rm loc}$}
For a radial <timelike geodesic> of specific <Killing energy> $k=f\,dt/d\tau$, the static observer measures $v_{\rm loc}=(dr/dt)/f=\dot r/k$. Its relative <Lorentz factor> is $k/\sqrt f$, giving $v_{\rm loc}^2=c^2(1-f/k^2)$.