The prize was awarded half to Roger Penrose for showing how black holes could form and half to Reinhard Genzel and Andrea Ghez for discovering a supermassive object at the Milky Way’s center.
Dr. Penrose, a mathematician at Oxford University, was awarded half of the approximately $1.1 million prize for proving that black holes must exist if "Albert Einstein’s theory of gravity, known as general relativity", is right.
The second half was split between Dr. Genzel and Dr. Ghez for their relentless and decades long investigation of the dark monster here in the center of our own galaxy, gathering evidence to convict it of being a supermassive black hole.
Dr. Ghez is only the fourth woman to win the Nobel Prize in Physics, following Marie Curie in 1903, Maria Goeppert Mayer in 1963 and Donna Strickland in 2018.
Black holes were one of the first and most extreme predictions of Einstein’s General Theory of Relativity, first announced in November 1915. The theory explains the force we call gravity, as objects try to follow a straight line through a universe whose geometry is warped by matter and energy. As a result, planets as well as light beams follow curving paths, like balls going around a roulette wheel.
Einstein was taken aback a few months later when Karl Schwarzschild, a German astronomer, pointed out that the equations contained an apocalyptic prediction: In effect, cramming too much matter and energy inside too small a space would cause space-time to collapse into a point of infinite density called a singularity. In that place (if you could call it a place) neither Einstein’s equations nor any other physical law made sense.
Einstein could not fault the math, but he figured that in real life, nature would find a way to avoid such a calamity.