THE UNIVERSE SPEAKS IN NUMBERS

Exploring the work of modern theoretical physicists, who are “taking a path that is entirely reasonable and extremely promising.”

A book on the role of mathematics in scientific discovery that contains little math seems a stretch, but Farmelo (Churchill's Bomb: How the United States Overtook Britain in the First Nuclear Arms Race, 2013, etc.) easily brings it off. It’s a cliché that scientists learn by observing and conducting experiments, but the author points out that the two greatest geniuses of modern physical science did neither. Isaac Newton’s great discoveries were less universal laws than the use of mathematics to describe them precisely—mathematics so complex that he had to invent an entire field, calculus. In studying gravity, Albert Einstein realized that space was curved rather than flat, and no physicist knew how to describe it. Fortunately, as a purely imaginative phenomenon, mathematicians had explained curved space a few decades earlier, and, with help from a mathematician friend, Einstein made his breakthrough. The idea that mathematicians could help physicists remained a minority view for most of the 20th century, until the flood of new observations diminished and experiments became increasingly expensive. By the 1980s, most physicists had changed their minds, fascinated by new, mathematics-based theories offering the possibility of explaining the nature of matter and finding the holy grail of physics: a way to unite quantum mechanics and general relativity. A downside is that these concepts deal with impossibly small phenomena (string theory) and new subatomic particles that have never been detected (supersymmetry); so far, they make no predictions that experimenters can test. By the 21st century, a growing body of physicists was complaining that this was leading nowhere. For a delightful account of this opposition, read Sabine Hossenfelder’s Lost in Math. Farmelo remains a believer, delivering lively biographies of brilliant researchers and their work up to the present, although much will be difficult for readers with no memory of college physics.

A thought-provoking look at a fierce, ongoing controversy over the future of theoretical physics.