"What is Life?" is a scientific exploration that delves into the intersection of physics and biology. The book presents the idea that life, at its most basic level, operates according to the laws of physics and chemistry. It introduces the concept of an "aperiodic crystal" that contains genetic information in its configuration of covalent chemical bonds, which later inspired the discovery of the structure of DNA. The book also discusses entropy and negentropy, suggesting that life feeds on negentropy to counteract the natural process of increasing entropy.

The book explores the parallels between modern physics and eastern mysticism. It draws connections between quantum mechanics, relativity theory and concepts in Hinduism, Buddhism, Taoism, and Zen. The author argues that the two seemingly disparate areas of study - physics and mysticism - both seek to understand the fundamental nature of the universe and that they do so in strikingly similar ways. The book challenges conventional thinking and encourages readers to see the world from a more holistic, interconnected perspective.