d s 2 = ( 1 − r s r ) c 2 d t − 1 ( 1 − r s r ) d r 2 − r 2 d Ω 2 {\displaystyle ds^{2}=\left(1-{\frac {r_{s}}{r}}\right)c^{2}dt-{\frac {1}{(1-{\frac {r_{s}}{r}})}}dr^{2}-r^{2}d\Omega ^{2}}