Frank L. H. Wolfs
Department of Physics and Astronomy, University of Rochester, Slide 51
The prediction of black holes.
¥Einstein viewed a star of any size as a cluster of particles; each particle orbiting the center of the star.
¥When the size of the star decreases, the orbital velocity of these particles will increase.
¥Einstein calculated that when the radius of the star would be 1.5 times the Schwarzschild radius, the orbital speed would be the speed of light.
¥Since only light can move with the speed of light, such a star can not exist, Einstein argued.  But É. maybe Einstein's model of a star is not correct.
Albert Einstein in his study at home
in Princeton, New Jersey, in 1938.