Throughout my career I’ve been surprised. Perhaps the most amazing surprise to me was actually one that I ultimately proposed but it defied everything I'd thought before. And that is this amazing result that empty space has energy.This opinion is odd. The Wikipedia article on Zero-point energy says that the concept is a century old, and has been essential to our understanding of quantum mechanics. In the 19th century, it was called the aether. People were skeptical about it being cosmologically observable, and I agree with giving a Nobel Prize for the 1998 astronomy work, but it was not so contrary to conventional wisdom. It was not a crazy idea.
It is so weird to think that you can get rid of all the particles and all the radiation in space and it still weighs something. It seems crazy. And when I was a graduate student, we were all certain that the energy of empty space was zero. And ultimately we were dragged - in fact, I was dragged, kicking and screaming by the observations - to propose this incredibly crazy idea that empty space has energy.
In fact, it’s been observed to have energy. In fact, the people who observed it won the Nobel Prize last year. And I think for me that has changed everything about my understanding of the universe. Both its past, its present, and its future. And I think it’s a wonderful example of how scientists are willing to throw out ideas like yesterday’s newspaper.
I agree with his point about throwing out failed ideas, but that means throwing out many-worlds interpretation, string theory, Bohm nonlocal mechanics, supersymmetry, black hole firewalls, proton decay, massless neutrinos, etc.
Update: Sabine Hossenfelder posts examples of papers before 1998 suggesting an accelerating cosmological expansion.