Before moving on to subjects other than quantum theory, which I've written about here and here recently, I want to talk in my own words regarding what I like about Carlo Rovelli's book, "Helgoland: Making Sense of the Quantum Revolution."
The previous posts consisted mostly of excerpts from the book. So here's my attempt to describe what appealed to me the most about Helgoland. (That's an island in the North Sea where Heisenberg came up with his key concepts about the quantum world.)
Rovelli is an exceptionally clear writer. He also has a poetic sense that isn't unique among physicists, but is uncommonly well developed in Rovelli. This book deals with notions that never made much sense to me, yet I largely accepted given that the ideas are embraced by so many experts in quantum theory.
For example, the idea that an observation by human consciousness brings a certain quantum reality into being. As Rovelli notes, galaxies billions of light years away obey the laws of quantum physics, as does everything else in the universe.
Consciousness doesn't exist everywhere, unless we assume that everything in existence possesses at least a minute form of proto-consciousness.
Ah, but if that is true, then there's no need to bring in human consciousness as the means by which the probabilistic nature of quantum equations, involving various possibilities, "collapse" down to a single outcome when an observation of an electron, photon, or whatever occurs.
The Many Worlds approach to quantum theory deals with the observation problem by positing that all possible outcomes of an observation occur, with reality splitting into an infinity of worlds at every instant, of which we inhabit only one of them.
The relational approach to quantum theory makes much more sense. Both the quantum world and the world familiar to us aren't made up of things, but of connections, of relationships.
Not family relationships, of course. Something much more general.
As I stare at my computer screen, there's a dance going on between the photons striking my eye, the pixels of the screen, vision processing centers in my brain, and more besides. Our dog would see something different. As would a snake. Or a bat.
I like how Rovelli says that there is no such thing as an outside perspective on the world or universe. It's all 100% inside, in two senses.
First, there's no way we can get outside of the universe, of everything that exists (some call this the cosmos). We humans, along with everything else, are part of the universe. We aren't experiencing the universe. One aspect of the universe is experiencing another aspect.
Or we can say, "The universe is experiencing itself."
Most books about quantum physics don't include a mention of Nagarjuna, the Buddhist thinker. But Rovelli's book does.
It isn't that Nagarjuna had a mystical insight into the nature of quantum reality. Rather, Rovelli says that ancient texts should be read not from the perspective of what the author initially intended to say, but how the work speaks to us today.
Rovelli writes that the central thesis of Nagarjuna is there is nothing that exists in itself independently from something else. Thus Buddhism fits in nicely with the relational approach to quantum physics.
Buddhism evolved in part as a reaction to Hinduism, which assumes the existence of soul, Atman, that is an aspect of God, Brahman. Buddhism denies that anything is eternal or unchanging, including ourselves, or our self.
So from the most minute subatomic particle to the grandest expanse of galaxies, with us humans occupying a middle ground, size-wise, relations are what reality is all about, not things.
We're alive because of our relationships with air, water, food, sunlight, other people, bacteria, cells, neurons, and everything else that makes it possible for us to be born, live, and yes, die.
The good news is, from the relational view of Rovelli's take on quantum physics and Buddhism, we never exist as a separate and distinct entity, so when we die, it is the relations that cease to exist. In a very real sense, each of us has never existed as the "I" we generally take ourselves to be.
The bad news is, there's nothing that can live on after the relations which sustain life are broken. But this is just reality speaking, and I don't see reality as dealing in good news and bad news. It simply is what it is.
Over and over in his book, Rovelli says that we need to embrace the idea that reality may be very different from how we currently consider it to be. This is how science is so successful: scientists do their best to understand reality as it actually is, even if that understanding is uncomfortable or surprising.
On his third page, in a section called Looking Into the Abyss, Rovelli writes:
But this is what science is all about: exploring new ways of conceptualizing the world. At times, radically new. It is the capacity to constantly call our concepts into question. The visionary force of a rebellious, critical spirit, capable of modifying its own conceptual basis, capable of redesigning our world from scratch.
I love those words.