What's the meaning of life? Physics.

nationalgeographic |  According to your book, physics describes the actions or tendencies of every living thing—and inanimate ones as well. Does that mean we can unite all behavior under physics?

Absolutely. Our narrow definition of the discipline is something that’s happened in the past hundred years, thanks to the immense impact of Albert Einstein and atomic physics and relativity at the turn of the [20th] century.

But we need to go back farther. In Latin, nature—physics—means “everything that happens.”

One thing that came directly from Charles Darwin is that humans are part of nature, along with all the other animate beings. Therefore all the things that we make—our tools, our homes, our technologies—are natural as well. It’s all part of the same thing.

In your magazine and on your TV channel, we see many animals doing this—extending their reach with tools, with intelligence, with social organization. Everything is naturally interconnected.

Your new book is premised on a law of physics that you formulated in 1996. The Constructal Law says there’s a universal evolutionary tendency toward design in nature, because everything is composed of systems that change and evolve to flow more easily. That’s correct. But I would specify and say that the tendency is toward evolving freely—changing on the go in order to provide greater and greater ease of movement. That’s physics, stage four—more precise, more specific expressions of the same idea.

Flow systems are everywhere. They describe the ways that animals move and migrate, the ways that river deltas form, the ways that people build fires. In each case, they evolve freely to reduce friction and to flow better—to improve themselves and minimize their mistakes or imperfections. Blood flow and water flow essentially evolve the same way.