A physicist’s grand tour of the Universe (book review)



In “Until the End of Time,” Brian Greene explores a stunning array of human thought, from evolution to consciousness.

If you’ve been reading popular physics books for a while, then you know the name Brian Greene. The Columbia University professor is known for a series of popular science books, beginning with 1999’s “The Elegant Universe,” that have brought string theory, the nature of space and time, and the question of parallel universes to a wide audience. With his new book, he casts a much wider net, seemingly positioning himself in the territory claimed by the likes of Steven Pinker and Yuval Noah Harari.

BOOK REVIEW “Until the End of Time: Mind, Matter, and Our Search for Meaning in an Evolving Universe,” by Brian Greene (Knopf, 448 pages).

With “Until the End of Time,” Greene is asking Pinker and Harari to hold his beer. The book covers a stunning array of human thought: There’s still plenty of physics, but we find that Greene also has a great deal to say about evolution; the origins of human culture; the dawn of art and music and storytelling and religion; the puzzle of consciousness; the paradox of free will. It’s an ambitious undertaking, to say the least.

It is perfectly reasonable to wonder if Greene — or any author — is to be trusted with such a multi-disciplinary project. Take biology, for example. Why do we need a physicist to tell us about the workings of living organisms? Because underneath the biology there is physics. And yet the laws of nature appear to pull on these two worlds in opposite directions. Physicists tell us that, according to the second law of thermodynamics, entropy — roughly, the amount of disorder in a system — must increase over time. But evolution, which shapes the living world, appears to add to the order and complexity found in nature. Let evolution loose on some organic compounds in a “warm little pond” (to use Darwin’s phrase), wait a few billion years, and before you know it, the autotrophs begin to drool.

And yet biology is beholden to physics. How, then, is a rabbit different from a rock? “Life does not and cannot contravene physical law,” Greene assures us. “Nothing can.” The trick is information. The DNA in the rabbit’s cells encodes instructions that tell those cells, and the molecules within, what to do. It guides them, as a waterslide guides a child’s descent into the pool — though cells and molecules are utterly oblivious to this guidance. “Life,” Greene writes, “is physics orchestrated.”

We, of course, are just as oblivious to this orchestration as the rabbit is (or the cell or the molecule, for that matter). Which means that in our daily lives we tell a different story, a “higher-level story” centered on humans and their interactions, without worrying about our component parts.

This idea — that nature offers hierarchical “levels” of description — is hardly new. Arthur Eddington wrote about it in his 1927 book “The Nature of the Physical World”; Sean Carroll (perhaps Greene’s closest competitor in the world of let’s-tackle-everything physics writing) explored it in some detail in “The Big Picture” and “Something Deeply Hidden.” But where Carroll emphasizes the distinction between the everyday view of reality and the physicist’s view (he says there’s a “yawning chasm between what we see and what really is”), Greene does not privilege one “story” over the other. We are particles; we are people.

Indeed, there is “little to be gained by physicists clamoring that theirs is the most fundamental explanatory framework or from humanists scoffing at the hubris of unbridled reductionism,” Greene writes. Different “levels” require different kinds of explanations, and, with effort, these stories can be woven together “into a finely textured narrative.”

Greene does not privilege our everyday view of reality over the physicist’s: We are particles; we are people.

Mind you, this leads to the sorts of puzzles that have stymied philosophers for thousands of years. Topping the list is the fact that we don’t feel like a bundle of particles blindly conforming to the laws of physics. We seem to be conscious; we seem to have free will. Greene acknowledges that this is “a critical gap in the scientific narrative.” We do not have “a conclusive account of how consciousness manifests a private world of sights and sounds and sensations.”

Undark for more

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