Black holes test our comprehension of physics. They’re extremes that are fascinating to study and difficult to understand. One of the most intriguing aspects of black holes is their intense gravity. It’s what allows them to trap anything that gets too close, even light. It’s what makes them so interesting in the first place. So how strong is the gravity around a black hole, really?
1. Black holes come in different sizes.
Not all black holes will have the same force of gravity, because they’re not all the same size. There are theorized miniscule black holes the size of an atom, all the way up to supermassive black holes that live in the centers of most galaxies. The bigger a black hole gets, the more powerful it is.
2. Lots of matter crammed into a small space.
The reason black holes have such incredible gravity is because of their size relative to their mass. If you took all the mass of the Earth and crammed it into a ball the size of a mosquito, you’d have a black hole. A large amount of mass in a very small space creates immense gravity, and immense gravity is characteristic of a black hole.
3. The event horizon tells you where the “safe zone” is.
As far as how strong the gravity is, that can be determined with the Schwarzchild radius, also known as the event horizon. This is the radius around the singularity (the center of the black hole) past which nothing, not even light, can escape. Knowing the Schwarzschild radius and the mass of the black hole, you can figure out the gravitational force for that specific black hole; spoiler alert, it’ll be a big number.