Ghez

Congratulations to Roger Penrose, Reinhard Genzel, and Andrea Ghez for wining the 2020 Nobel Prize in Physics for their contributions to establishing the existence of black holes. A black hole is an object with an infinite density of matter and curvature of space-time. Black holes typically form when a massive star (at least ten times the mass of the sun) runs out of fuel, and the outward pressure of nuclear explosions inside the star can no longer compensate for the inward pressure of gravity. When that happens, the star collapses in a phenomenal explosion called a supernova. All the matter of the star implodes into the singularity—the center of the star. According to Einstein’s general theory of relativity, the density and space-time curvature at the center become infinite. In the real world, of [...]