Reality Is Not What It Seems: The Journey to Quantum Gravity

Quantum Leap in Clarity

I read Carlo Rovelli’s book about quantum gravity (for the first time, it will take me a few goes, at least, to get all that is in it.) He is quite a good writer and this book, like his seven lessons in physics, is clear and extremely literate (I imagine he wrote it in Italian, but the English is smooth and demotic and lucid. It is a pleasure to read, which is not the norm in books that try to explain physics to non-specialists; God help the guy who tries to read the specialist literature. After a review from Democritus to Einstein et al, he gives us three big conclusions. At the smallest level, the universe is granular, relational, and indeterminate. He makes some other amazing statements like that ‘time’ disappears at this level and that things only exist when they collide into each other (or as ‘events’ as he puts it.) I have a notion about these other statements, but I have to determine if I understand the big three first. Everything (like Democritus and Feynman told us) is made of “atoms” or actually irreducible ‘quanta.’ Each of which is a unit of stuff that cannot be further divided; matter is not infinitely divisible (NB; big point.) Eventually, you get to a tight-pack of Plank scale bits of somethingness that all fit together. They in their constellation are gravity, space, and at bottom, everything else. There is no overarching, organizing anything outside these quanta. Time is absolutely a characteristic of the situation of the observer and the variable being measured “in” or as “time;” it measures differently at different altitudes and in different circumstances of proximity to matter and because of other factors. There are times all over the place and they do not generalize. At the level of the granular quanta, it disappears as a factor entirely. The stuff of the universe is not strictly determined in terms of how things interact and the results of any given intervention in it. We can pretty much depend on certain things happening as if by cause and ...