astronomer and theoreticical physicist who was the first to substitute
a photographic plate at the telescope in place of the eye and then measure
densities with a photometer.
He designed and constructed some of his own instruments.
Schwarzschild was born in Frankfurt and studied at Strasbourg and Munich.
In 1902 he was appointed professor at Göttingen and director of
the observatory. From 1909 he was director of the Astrophysical Observatory
at Potsdam. He was the father of Martin Schwarzschild.
In 1900, he suggested that the geometry of space was possibly not in
conformity with Euclidean principles. (This was 16 years before the
publication of Albert Einstein's general theory of relativity.) He later
gave the first exact solution of Einstein's field equations.
Schwarzschild introduced the concept of radiative equilibrium in astrophysics
and was probably the first to see how radiative processes were important
in conveying heat in stellar atmospheres. In 1906, he published work
on the transfer of energy at and near the surface of the Sun.
He devised a multi-slit interferometer and used it to measure the separation
of close double stars. During a total solar eclipse 1905, he obtained
spectrograms that gave information on the chemical composition of regions
at various heights on the Sun. He later designed a spectrographic objective
that provided a quick, reliable way to determine the radial velocities