It would be the greatest moment in physics: the final theory of everything. At last, we would understand everything, including the things that still puzzle us. The greatest minds of our time wanted to crack the theory, including Heisenberg, Einstein, and Hawking. All of them failed. Is there still hope that we'll find it?

We seemed to be on a good path. We had the theories of classical physics, with which we understood the laws that governed nature. But then physicists discovered a completely new world where suddenly nothing was as they knew it: the quantum world. Even though we still don't really understand it today, we know that a world without quantum mechanics would be a different one.