English: The picture of space falling into a black hole has a sound mathematical basis, first discovered in 1921 by the Nobel prize-winner Alvar Gullstrand, and independently by the French mathematician and politician Paul Painlevé, who was Prime Minister of France in 1917 and then again in 1925. Physically, the Gullstrand-Painlevé metric describes space falling into the Schwarzschild black hole at the Newtonian escape speed. Outside the horizon, the infalling speed is less than the speed of light. At the horizon, the infalling speed equals the speed of light. And inside the horizon, the infalling speed exceeds the speed of light. Although nothing can travel through space faster than the speed of light, space itself can infall at any speed.