Book Report: Seven Brief Lessons on Physics, by Carlo Rovelli

Book Report: Seven Brief Lessons on Physics, by Carlo Rovelli

To start with, this is a well-written book. The author writes lyrically about some of the most fascinating aspects of modern physics. Also, it’s short: only 81 pages. For non-experts, this could be the perfect intro to many of the physics topics that crop up in the news lately, including quantum mechanics, black holes, the Higgs boson, and dark matter.

However, for these same reasons, it’s a little light on details. It’s rather like a buffet of appetizers: many tasty morsels, but not very filling.

Now, I happen to have a background in physics, including a PhD in theoretical physics. I’ve been a college professor, taught science and calculus, and published in journals. Not that I’m at all well-known or accomplished: but I do have a slightly different view of these topics than the average non-expert reader. And what strikes me most about them isn’t what the author says, but what he doesn’t say.

For example, he tells the story of Max Planck performing a certain calculation, and using for the first time the concept of a “quantum” of energy. But what he doesn’t tell you is why Planck was doing this, or why he tried using the quantum to get the right answer. The reason is simple: the physics of the time had failed miserably to get the answer right. Physicists put everything they knew about electricity and light and energy into their calculation, and they were spectacularly wrong. They were so far off that the problem was called the “ultraviolet catastrophe.”

Similarly, he tells the story about Einstein also using the concept of a quantum of energy as a way to explain the photoelectric effect, where light falling on metal causes electricity to flow. Again, he doesn’t reveal to us why Einstein was doing this. It was because, once more, the physics of the time had failed utterly. Using everything they knew about light and electricity, for example, physicists had predicted that, if you shined light on a metal, it would take a few minutes for the light to cause the electricity to flow. In reality, the electricity starts immediately. This is incomprehensible in classical physics, and only the use of the quantum gives a satisfying explanation.

Finally, he talks about Niels Bohr coming up with a picture of the atom that leads to electrons being in set, stable orbits, and making the now-famous quantum leaps between orbits. What he doesn’t talk about is why this idea is necessary: because ordinary physics predicts that all electrons should spiral into the nucleus in a thousandth of a second: there would be no stable atoms, ever.

Why does the author omit discussing these motivations for the advances in physics he presents? I don’t know, of course, but I suspect that he wants to present physics as a magnificent edifice of marble and bronze, perfect and eternal. To this edifice, giants such as Planck and Einstein and Bohr contribute new wings, and every student of physics can aspire to offer some small improvement.

It’s a noble image, and one that probably impresses the tourists, but it’s absolutely false. In reality, physics is a ramshackle hodge-podge cobbled together with chewing gum and baling wire. It works remarkably well, and with more rigor than any other science, but it is far from perfect and even far from consistent. This leads to some howlers in this book, such as “the equations of the [quantum] theory finally appeared, replacing those of Newton”. Um, not really. The equations of quantum mechanics are good almost solely for phenomena about the size of an atom or smaller. For everyday life, Newton’s equations work just fine, thank you very much.

I wonder if the author is presenting this shining exterior to win readers over to his viewpoint, which is thoroughly materialistic. Materialism is the philosophy that the world consists of inert matter subject to the forces of nature, and that’s it. In materialism, there is nothing of the spiritual, of the soul, of the mind. To a materialist, human beings are something like complex machines, and anything produced by a human being is something like the result of a printing press, not of any individual creativity. The author seems to value music, art, and literature, but, as a materialist, he must believe that these are simply the by-products of the biochemical reactions of the brain.

In fact, he states so much in this book: you are your brain. There is nothing of you besides what goes on in that organ.

I don’t know how a materialist can esteem certain human beings, such as Planck or Einstein or Bohr. Surely, their brains were simply doing what their brains came into being to do, right? Why should they receive any special acclaim simply for performing the process they had no choice but to perform?

He goes even further: “An individual is a process.” In other words, you are something like a rusting can, or a rock being eroded by water. No more, no less.

It’s not surprising that such a bleak view of life leads to a bleak view of the future. “I believe that our species will not last long,” he states. Given this view, one wonders why he would bother to be interested in unraveling the mysteries of the universe, or indeed, why he would want to gain adherents for his views. Why would it matter (rimshot)?

Still, those of us who believe there is more to human beings than physical and chemical reactions can still value his descriptions of the magnificence of the universe, and the singular and amazing fact that we can actually understand some of how it all works.

Recommended, but mind the gaps.