We should all be grateful that Werner Heisenberg suffered from a bad case of hay fever. If it wasn’t for that affliction, he wouldn’t have taken time off to seek isolation at the remote—and treeless—island of Helgoland, where his racing mind revolted against idleness and cracked open the pivotal equation that gave rise to quantum mechanics. The resulting paper was described by Nobel Prize laureate Steven Weinberg like so:

Theoretical physicists in their most successful work tend to play one of two roles: they are either sages or magicians… It is usually not difficult to understand the papers of sage-physicists, but papers of magician-physicists are often incomprehensible. In that sense, Heisenberg’s 1925 paper was pure magic.

From The Quantum Universe | Brian Cox & Jeff Forshaw

The most fascinating aspect of Heisenberg’s discovery is that the strange formula he had conceived failed to make sense even to himself.

It generally doesn’t matter if you multiply three by four or four by three; both will yield the same answer. In stark and confusing contrast, Heisenberg’s calculations gave different results depending on which order you ran the numbers.

It was only as the young prodigy (Werner was 23 at the time) returned to Göttingen that his supervisor, Max Born, enlightened him. Heisenberg had stumbled across an exotic branch of mathematics called matrix algebra, in which the order of operations fundamentally alters the outcome. Technical term: the numbers are non-commutative.

Non-commutability wasn’t just a mathematical curiosity, it’s what led Heisenberg to formulate the uncertainty principle, which states the fundamental limit to what can be known about a quantum system’s observable properties.

I came across the story of Heisenberg’s discovery many months ago, as I read Carlo Rovelli’s book Helgoland : The Strange and Beautiful Story of Quantum Physics.

Although I enjoyed it I had a distinct feeling that much of Rovelli’s wisdom went over my head. I just wasn’t cognitively prepared to fully appreciate his “radically observer dependent interpretation” of quantum mechanics.

After ripping through Helgoland, I continued on a quantum reading binge, where the latest stop was Amanda Gefter’s bookTrespassing on Einstein’s Lawn : A Father, a Daughter, the Meaning of Nothing, and the Beginning of Everything.

That book chronicles the author’s sixteen-year-long quest to understand where theoretical physics as a field is moving, and ultimately what its current consensus is on the question of how the universe came to be.

It’s a lovely read, but also quite dense. Starting in good old quantum mechanics, it quickly nose-dives into string theory, M-theory, the holographic principle and a host of other obscure frameworks that are all vying for thought leadership in the tightly knit community of world-leading theoretical physicists.

As I’m nearing the end of Gefter’s book, my head is spinning. By shadowing the author as she meets with one after another of the cutting-edge scientists who are likely to receive future Nobel prizes, I’ve just about had all I can take. I’m against the ropes.

That’s when, in the very last chapter, Gefter arrives at the theoretician who ties it all together; the one who’s been heralded by the great John Archibald Wheeler as equal to (his erstwhile friend) Albert Einstein.

That person is Carlo Rovelli.

And now that I come back to him, now that I see his point of view reflected through someone else’s temperament and frame of reference, it all makes so much sense.

Sense, I feel, in a way that wouldn’t have happened if I hadn’t read the last ten or so books the exact order in which I did.

It’s fascinating how books aren’t mere repositories of information. That the order in which you encounter them actually dictates how your understanding evolves.