THE ORDER OF TIME - CARLO ROVELLI
This one’s a real brain-fucker. It makes sense that Rovelli makes reference to both mushrooms and LSD, he certainly gave me a ton to think about the next time I’m in one of those zones. If you’ve followed this “blog” (which I don’t think anyone is) you might have noticed I’m something of a “time guy.” I generally eschew pop-physics stuff because I’m dumb and it typically is a little woo-woo for me, but I am always interested in the latest theories about how time works and what it is and the implications of all that. This is one of the best of these sorts of books I’ve ever read, it doesn’t pretend to explain the math or anything like that to you (which I always resent since clearly the “real math” involved is much to complicated for me to have an opinion about whether or not it’s “right”), it merely lays out the current high-end theoretical physics thinking on the subject then goes into some speculation and finally, seeks to rectify one of the biggest questions about time that authors of this sort of book typically ignore. It’s pithy and pretty poetic, and manages to not oversimplify, nor to get bogged down in the weeds. I'll do my best to sum up what I understood from the book. The first big idea to wrap one’s head around is the non-universality of time, how there is no “present” between us and stars light years away, ”Notion of “the present” refers to things close to us, not far away,” and, ”There is a present that is near to us, but nothing that is “present” in a far-off galaxy. The present is a localized rather than global phenomenon” are how he puts it in the book. Or, even more profoundly, “The world is like a collection of interrelated points of view. To speak of the world “seen from outside” makes not sense, because there is no “outside” to the world.” From there we learn all sorts of bizarre things about time, such as the idea of a Planck time, which lasts roughly 10^-44 seconds and is the most granular unit of time, “below this the notion of time does not exist - even in its most basic meaning,” which is pretty insane idea and not one I think I’ve fully wrapped my head around. Basically, on the most fundamental level, there isn't’ space or time, or even things, there is merely a collection of quantum events happening at insane speeds constantly, creating a sort of “spinfoam” that our brains build reality out of. “In the elementary grammar of the world, there is neither space nor time - only process that transform physical quantities from one to another, from which it is possible to calculate probabilities and relationships.” This is all well and good, if very far-out. If you think about the fact that the earth spins you can begin to understand how the world could function in a way that is at odds with our perception. The second part of the book is even more far-out and tries to explain why time feels the way it does to us. He brings up the point that the law of entropy is the only fundamental law of physics that uses a notion of time (in that heat can’t go from cold to hot so the causal chain only works one way in time) and the flow of time that we experience is really the result of this increase in entropy: “The directionality of time is therefore real but perspectival: the entropy of the world, in relation to us (sic) increases with our thermal time. We see the occurrence of things ordered in this variable, which we simply call “time” and the growth of entropy distinguishes the past from the future for us and leads to the unfolding of the cosmos...This is what we are listening to when we listen to the passing of time.” I won’t pretend I can understand this stuff fully or even substantially, but I do like thinking about it. There certainly is something weird going on with time, if you think about it for a while, it doesn’t make a ton of sense. I’m glad he managed to find a middle way between “what we experience is real” and “we live in a block universe with no past/present/future.” He manages to do away with the present as previously understood and instead fleshes out another paradigm, ”What causes events to happen in the world, what writes history, is the irresistible mixing of all things, going from a few ordered configurations to the countless disordered ones. The entire universe is like a mountain that collapses in slow motion. Like a structure that very gradually crumbles.” He sort of gets his Wittgenstein on towards the end of the book, writing, “when we cannot formulate a problem with precision, it is often not because the problem is profound: it’s because the problem is false.” but he manages to explore all these problems-without-precision with a ton of insight. If you’re into this shit, pick it up and get your mind blown. An infinite number of presents, pasts and futures