Karl Schwarzschild
Karl Schwarzschild was a very smart man. He studied math and physics and made discoveries that helped us understand space and time better.
One of the things he figured out was how to measure the size of a star. He realized that the bigger the star, the stronger its gravity. He also found a way to measure how far away things are in space.
But one of the most amazing things he did was to figure out a way to describe the space around a black hole. A black hole is a very strange thing in space where gravity is so strong that not even light can escape. Schwarzschild figured out the math that describes how gravity works near a black hole.
He did all of this way back in the early 1900s, before we even had telescopes that could see into space very well. We still use his work today to understand the universe!
One of the things he figured out was how to measure the size of a star. He realized that the bigger the star, the stronger its gravity. He also found a way to measure how far away things are in space.
But one of the most amazing things he did was to figure out a way to describe the space around a black hole. A black hole is a very strange thing in space where gravity is so strong that not even light can escape. Schwarzschild figured out the math that describes how gravity works near a black hole.
He did all of this way back in the early 1900s, before we even had telescopes that could see into space very well. We still use his work today to understand the universe!