How Grainy Is Your Reality?

I’m in the process of reading the book Reality Is Not What It Seems: The Journey to Quantum Gravity by Carlo Rovelli. I figured I’d write a bit about each chapter as I go along. Maybe this will help me integrate the ideas a better than if I simply read it.

I’ll give it a try, anyway, even if am suffering from the horrors of the WordPress editor at the moment (BTW, what gives, WP? Why did you move from a relatively user-friendly UI to this exceptionally unfriendly block system that specializes in producing heartburn and headache in equal proportions? Just wondering.)

The Ancient Power of Democritus

The first chapter is called “Grains,” which I assume is a reference to two things: 1) the fact that we are starting with the seminal ideas of today’s physics going back to ancient Greece and 2) the fact that the topic is atoms, which are the grainy little building blocks that reportedly make up our reality.

Rovelli, a theoretical physicist and science writer, insists that our current best understanding of reality began around 450 BCE with a Greek named Leucippus, the teacher of Democritus. “Together,” writes Rovelli, “these two thinkers have built the majestic cathedral of ancient atomism. Leucippus was the teacher. Democritus, the great pupil who wrote dozens of works on every field of knowledge, was deeply venerated in antiquity, which was familiar with these works.”

Rescued from Obscurity by Latin Poetry?

Why don’t we know more about these two great philosophers? Because, according to Rovelli, the texts of these philosophers were systematically destroyed by Christians in accordance with their ideas about reality. “Plato and Aristotle, pagans who believed in the immortality of the soul or in the existence of a Prime Mover could be tolerated by a triumphant Christianity,” he writes. “Not Democritus.”

These losses are tragic, especially given the very long list of works by Democritus, who looks to have been just as prolific as Aristotle. The good news is that a little about the philosophy of atomism was preserved in a work by the Latin poet Lucretius: that is, De rerum natura, or The Nature of All Things.

The Catholic Church really had it out for atomism. In the 1500s, they even tried to ban the works Lucretius but failed. Lucretius was already in the bloodstream of European thinkers and they were not going to give him up. Rovelli describes the work as “an articulate and complex structure of thinking about reality, a new mode of thinking, radically different from what had been for centuries the mind-set of the Middle Ages.”

Einstein and Atomism

So atomism survived by the skin of its philosophical teeth. Would we have today’s understanding of the universe without it? Impossible to know, of course, but Rovelli seems to think not. What’s especially interesting is Einstein’s role in atomism, a role I’d never heard about before. Apparently Einstein knew of the experiments of the 19th century biology Robert Brown, who graphed the movement of small particles suspended in water. The particles, it turns out, do not fall straight down. They move around in a zigzag manner.

Why does this happen? Because, Einstein hypothesized, the molecules in the water are colliding with one another. He even figures out the the approximate size of these tiny particles: “From observations of granules drifting in fluids, from the measurement of how much these ‘drift’ — that is, move away from position — he calculates the dimensions of Democritus’s atoms, the elemental grans of which matter is made. He provides, after twenty-three hundred years, the proof of the accuracy of Democritus’s insight: matter is granular.”

A Suspiciously Specific Dawn

Do I buy all this? Sort of. My impression is that it’s seriously oversimplified, as good stories often are. But it sounds generally true. Yes, I’m skeptical that the “first dawn of scientific thought” occurred only at Miletus in the sixth century BCE. That seems overly specific to me. I imagine that scientific thought is more organic than that, having begun thousands of years before when prehistoric humans slowly uncovered the workings of the natural world.

I think about Ötzi the Iceman, for example, who lived about 5,000 years ago and how his hair was heavily contaminated with copper and arsenic, suggesting he was somehow associated with copper smelting. That is pretty serious technology for an age millennia before Democritus was born. After all, such technology requires considerable patience, insight and multi-generational knowledge. In short, I doubt metallurgy is possible without the kind of reasoning that may itself be considered part of an extended dawn of scientific thought.

But that’s just nitpicking. Even if he is simplifying and mythologizing a bit, Rovelli tells a good and insightful story, one that I’ll remember even if I ultimately get a little fuzzy about the dates and names.

Featured image:  "The Young Rembrandt as Democritus the Laughing Philosopher", a portrait study, half length oil on copper, bears monogram top left "HL?" and lengthy French hand written inscription verso, 23.75 × 17 cm’). Go to https://commons.wikimedia.org/wiki/File:Rembrandt_laughing_1628.jpg