The Order of Time: a short book I read very slowly
Two hundred pages and it took me three weeks, which for me is the mark of either a bad book or a dense one. This is the dense kind. Every chapter is short and every chapter needs a walk afterwards.
The argument, as far as I followed it: the single flowing universal time we experience is not a basic feature of the world. Time runs at different rates depending on where you are and how fast you move, there is no shared present across distance, and at the smallest scales the neat ordering of before and after becomes something much blurrier. What we call the direction of time may be a fact about our own coarse view of things rather than a fact about things.
The first third, which is mostly demolition, is the strongest. It is careful, concrete, and full of the kind of example that survives being retold at a dinner table: two clocks at different heights on a mountain, ticking at genuinely different rates, verified by measurement.
The middle third, on what replaces time, I understood less well than I would like. I could follow each sentence and could not always hold three sentences together. That is probably an honest outcome for a lay reader and the author does not pretend otherwise.
The last third turns lyrical and I was of two minds. There are passages about memory and grief that are moving on their own terms, and there are passages where a metaphor is asked to carry an argument. When the physics has been that careful, the shift is noticeable.
Worth reading if you like having a settled intuition taken apart in front of you. I finished it slightly less sure of what a moment is, which I assume was the point.