It’s hard to argue with the famously authoritative Oxford English Dictionary, but its definition of physics as the “branch of science concerned with the nature and properties of non-living matter and energy” is incomplete because physics studies living things as well. Physicists reported biological research at their first international meeting in 1900, and physics and math still help biologists understand living things.

In a striking reverse connection, in the 1940s Albert Einstein and Erwin Schrödinger, founders of relativistic and quantum physics, respectively, projected that tackling questions of biological importance could also enhance physics. They were right: Today researchers are exploring “information” as more than a vaguely defined idea. Instead it has become a specific and unifying concept with deep meaning in both physics and biology.

The first major work to put physics and math into biology came much earlier. The Scottish biologist and polymath D’Arcy Wentworth Thompson published in 1917, with a massive 1,116 page second edition in 1942. It explains that the structure of organisms exists “in conformity with physical and mathematical laws.” Arguing that Darwin’s natural selection is incomplete, Thompson showed how to extend the