Something Deeply Hidden
Quantum Worlds and the Emergence of Spacetime
Dutton Books 2019
Quantum mechanics is the most important idea in physics, and physicists themselves readily admit that they don't understand it. But rather than treating this situation as an urgent call to action, they have traditionally pretended that the problem isn't there. In Something Deeply Hidden, Sean Carroll argues that this situation is embarrassing and unnecessary, as we do have a very promising way of understanding quantum reality: the Many-Worlds theory, pioneered by Hugh Everett. This book demystifies the paradoxes of quantum mechanics, explains the Many-Worlds approach at a level never previously attempted in a popular work, and argues that an improved understanding of the foundations of quantum mechanics is crucial to making progress on quantum gravity and the emergence of spacetime.
“I was overwhelmed by tears of joy at seeing so many fundamental issues explained as well as they ever have been. Something Deeply Hidden is a masterpiece, which stands along with Feynman's QED as one of the two best popularizations of quantum mechanics I've ever seen. And if we classify QED as having had different goals, then it's just the best popularization of quantum mechanics I've ever seen, full stop.”
—Scott Aaronson, professor of computer science at the University of Texas at Austin, and Director of UT’s Quantum Information Center
You don't need a Ph.D. in theoretical physics to be afraid of quantum mechanics. But it doesn't hurt.
Quantum mechanics is the most successful and fundamental physical theory ever devised by human beings. Yes, in the famous words of Richard Feynman, "I think I can safely say that nobody really understands quantum mechanics."
Physicists should be outraged by our lack of understanding, and devote extraordinary resources and brainpower to figuring out what quantum mechanics really is and what it implies about the world. Instead, for many decades we have refused to take the problem seriously, choosing instead to "Shut up and calculate!" Calculating is always good, but it's time to speak up and do some hard thinking.
Something Deeply Hidden aims to demystify quantum mechanics, insisting that it's just as sensible and intelligible as any other physical theory. The best way we currently have to make sense of quantum phenomena -- always subject to change if new data come in, of course -- is the Many-Worlds formulation, put forward by Hugh Everett in the 1950's.
Many-Worlds isn't a baroque addition to a simple formalism; it is the simplest possible formalism to make sense of the data we've collected, but it has far-reaching and mind-stretching implications for how we think about ourselves and our place in reality. Among these implications are straightforward lessons for how we should tackle other looming questions in physics, most obviously the long-standing issue of reconciling quantum mechanics with general relativity, Einstein's theory of spacetime and gravity.
Something Deeply Hidden will convince you that understanding quantum mechanics is a crucially important and entirely attainable goal. It delves into the details of Many-Worlds in a way never before done in a book for the general reader. And it will introduce cutting-edge ideas in quantum gravity, showing how curved spacetime might have been lurking in the quantum wave function all along.