Karl Schwarzschild

Karl Schwarzschild (9 October 1873 – 11 May 1916) was a German physicist and astronomer.

Best known for his solution to Einstein's equations of general relativity, which describes the gravitational field outside a non-rotating black hole with no magnetic field.

The equation describes how a particle moves space near this black hole (using spherical coordinates).

${\displaystyle (ds)^{2}=-c^{2}(1-{\frac {r_{s}}{r}})(dt)^{2}+{\frac {1}{(1-{\frac {r_{s}}{r}})}}(dr)^{2}+r^{2}(d\theta )^{2}+r^{2}\sin ^{2}(\theta )(d\phi )^{2}}$

ds is the path it follows
dt is the change in time
dr is the change in radius
d${\displaystyle \theta }$ and d${\displaystyle \phi }$ are the change in angle
${\displaystyle \theta }$ is also the angle
${\displaystyle r_{s}}$ is the set radius limit of the heavy object
r is how close the travelling object is to the heavy object
c is the speed of light

This equation is also known as the Schwarzschild metric or Schwarzschild solution.^[2]