Physics students learn about the basic stuff of realityspace and time, energy and matter"and are told that all other scientific disciplines must reduce back down to the fundamental particles and laws that physics has generated. This philosophy, called "reductionism," worked pretty well from Newton's laws through much of the 20th century as physicists discovered electrons, quarks, the theory of relativity, and so on. But over the past few decades, progress in the most reductionist branches of physics has slowed. Physicists largely ignored living systems. But today, many of my colleagues ... have come to believe that a mystery is unfolding in every microbe, animal, and human"one that challenges basic assumptions physicists have held for centuries, and could answer essential questions about AI. It may even help redefine the field for the next generation. Beginning in the 1980s, physicists ... began developing new mathematical tools to study what's called "complexity""systems in which the whole is far more than the sum of its parts. Throughout the current AI boom, researchers and philosophers have debated whether and when large language models might achieve general intelligence or even become conscious. As the 21st century continues to unfold, my fellow physicists will undoubtedly continue to advance the study of black holes, quantum mechanics, and other traditional domains. The study of life, however, will take us to places we've never imagined, opening a path for the future of our field that, for once, unfolds on a level playing field with biologists, ecologists, neuroscientists, and sociologists. At its best, the pursuit of fundamental answers about the nature of living things might lead physicists not only to new scientific marvels, but also to an entirely new way of doing science.