I finished ** The Quantum Labyrinth: How Richard Feynman and John Wheeler Revolutionized Time and Reality** (2017), by

**Paul Halpern**. As the title implies, the book revolves around the careers and lives of John A. Wheeler (1911–2008) and Richard Feynman (1918–1988). After Feynman graduated from MIT he became Wheeler’s teaching assistant at Princeton. The two men, despite very different personalities, became life-long friends and collaborators.

One of Wheeler’s many claims to fame is his promotion of Hugh Everett’s PhD thesis, *The Theory of the Universal Wave Function*. That paper, of course, is the seed from which grew the **Many Worlds Interpretation** of Quantum Mechanics.

The thing is, there are two major versions of the MWI.