A short essay about black holes

From the foreword by Dr. rer. pol. Erik KolekIn this short essay about black holes all the interesting aspects of black holes are shown. So what are black holes? Black holes are past stars that have been created by a gravitational collapse. They used to be called frozen stars. These cold black stars are the remnants of stars in the form of matter. Black holes are not only black but can also radiate brightly. These gravitational singularities can therefore emit and absorb matter at the same time. Space-time in the black hole region is extremely curved and can no longer be considered flat.