#115 – David Wallace on the many-worlds theory of quantum mechanics and its implications

Quantum mechanics — our best theory of atoms, molecules, and the subatomic particles that make them up — underpins most of modern physics. But there are varying interpretations of what it means, all of them controversial in their own way.

Famously, quantum theory predicts that with the right setup, a cat can be made to be alive and dead at the same time. On the face of it, that sounds either meaningless or ridiculous.

According to today’s guest, David Wallace — professor at the University of Pittsburgh and one of the world's leading philosophers of physics — there are three broad ways...