Singularity
The general theory of relativity predicts that a so-called "singularity" is hidden in a black hole (i.e. behind an event horizon). A thought experiment from school physics: A space capsule is on the moon. The astronauts want to teach back to earth. To do this, they have to overcome the moon's gravitational field. If they only had a catapult instead of a rocket drive, this would have to throw the space capsule into space at a certain speed so that it does not fall back onto the moon. Escape speed This speed can be calculated solely from the mass of the object to be left and its radius (position of the space capsule on the surface). For the moon it is: 2.3 km/s. If the astronauts not only want to leave the moon, but also our solar system via catapult, the escape speed is 42.1 km/s, and for our galaxy: 320 km/s. In order to leave our universe, however, our atronauts would have to be faster than light. However, since physics does not allow mass to ever move faster t...