Inspired by an essay written by physicist and novelist Alan Lightman, Robert pays a visit to Brian Greene to ask if the latest developments in theoretical physics spell a crisis for science -- where we find we've reached the limit of what we can see and test, and are left with mathematical equations that can't be verified by experiments or observation.That essay says
It is important to point out that neither eternal inflation nor string theory has anywhere near the experimental support of many previous theories in physics, such as special relativity or quantum electrodynamics, mentioned earlier. Eternal inflation or string theory, or both, could turn out to be wrong. However, some of the world’s leading physicists have devoted their careers to the study of these two theories. ...Lightman is expanding this essay into a book. I guess it will explain how the world's leading physicists have wasted their careers on untestable theories that were supposed to explain the universe from first principles, but they have now all decided that we live in a multiverse that can never be explained. Greene apparently still believes in some sort of mathematical theory of everything.
“We had a lot more confidence in our intuition before the discovery of dark energy and the multiverse idea,” says Guth. “There will still be a lot for us to understand, but we will miss out on the fun of figuring everything out from first principles.”