While browsing the Philosophy section during our recent visit to Powell's Books, I found myself intrigued by An Introduction to the Philosophy of Time. I suddenly realized that I wanted to know more about the nature of time. (This is exactly the kind of experience I want and expect from Powell's: the abrupt upwelling of a desire I didn't know I had to explore a subject or author.) That specific book was new and expensive with few mixed reviews, so I wandered over to the Physics section and considered the numerous options with "Time" in their title. I ended up with From Eternity to Here, which admittedly doesn't have "Time" in its title.
I am very happy with my choice. From Eternity to Here is exactly what I hope for in a science book: an engaging style, a new perspective, and just the right percentage of material that goes over my head.
The fundamental mystery is why time travels in just one direction when all other dimensions of spacetime allow travel in any direction and the laws of physics are inherently reversible. The answer – or the evidence that points toward an answer – has to do with the Second Law of Thermodynamics, which says that entropy is always increasing. Why and how did the universe start in a state of such low entropy? In other words, pondering the nature of time reduces to pondering cosmology, information theory, and the laws of physics, the mysteries of relativity, quantum mechanics, gravity. Carroll does a nice job of showing how the various mysteries fit together. He is also honest about the limitations of our knowledge: while the goal of science is "to understand the behavior of the natural world," our comprehension of the fundamental mechanisms falls short of that goal.
I am very happy with my choice. From Eternity to Here is exactly what I hope for in a science book: an engaging style, a new perspective, and just the right percentage of material that goes over my head.
The fundamental mystery is why time travels in just one direction when all other dimensions of spacetime allow travel in any direction and the laws of physics are inherently reversible. The answer – or the evidence that points toward an answer – has to do with the Second Law of Thermodynamics, which says that entropy is always increasing. Why and how did the universe start in a state of such low entropy? In other words, pondering the nature of time reduces to pondering cosmology, information theory, and the laws of physics, the mysteries of relativity, quantum mechanics, gravity. Carroll does a nice job of showing how the various mysteries fit together. He is also honest about the limitations of our knowledge: while the goal of science is "to understand the behavior of the natural world," our comprehension of the fundamental mechanisms falls short of that goal.
Physicists are completely confident in how they use quantum mechanics – they can build theories, make predictions, and test against experiments, and there is never any ambiguity along the way. Nevertheless, we're not completely sure what quantum mechanics really is.Whenever I read a book like this one, I always wonder what conceptual breakthrough will finally allow us to understand what's going on.
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