# Timelike, spacelike, or null?

If I have a line element $$ds^{2} = ...$$ and a curve defined by $$x^{1} = f( \lambda )$$, $$x^{2} = g( \lambda )$$ etc, and I wand to know if the curve is timelike, spacelike, or null, do I do so by checking the sign of $$g_{\mu \nu} \frac{dx^{\mu}}{d\lambda} \frac{dx^{\nu}}{d\lambda}$$ ?

## Answers and Replies

Related Special and General Relativity News on Phys.org
George Jones
Staff Emeritus