Physicists have solved one of the most important unsolved puzzles of the mathematical theory of relativity. Some see it as a milestone in its development.
Few terms invented by physicists have had as great a career as “black hole.” The term, coined in the mid-1960s by American physicist John A. Wheeler, describes a region of space-time into which one can fall and into which one can no longer escape. Wheeler, describes a region of space-time into which one can fall, and from which one can no longer get out. Another version claims that a few years earlier, American physicist Robert Dicke physicist used a comparison of these areas to the Black Hole of Calcutta — a prison from which, according to legend, no one has come out alive.
Over the past decade, black holes have featured heavily in news reports. In 2015, the LIGO/Virgo team first observed gravitational waves created by the merging of two supermassive black holes (the discovery was honored with a Nobel Prize in 2017). Three years later, black holes came to Stockholm again, this time to celebrate the observational confirmation of the existence of a large object of this kind at the center of our galaxy. And quite recently, pictures of black holes taken by the Event Horizon Telescope made headlines around the world.
It would seem that we also know a great deal about black holes on a theoretical level. But are we sure?
The latest solution is already 60 years old
The existence of objects from which nothing, not even light, can escape was speculated about as early as the second half of the 18th century. A few months after Einstein formulated the General Theory of Relativity, in 1916, German astronomer Karl Schwarzschild found a simple solution to the theory describing a static (unchanging) black hole. For many years, admittedly, physicists — including Einstein — believed that this solution could not describe the objects that exist in the universe, but we have known well for several decades that they can exist. And indeed they do exist.