From Eternity to Here

Notes

From Eternity to Here by Sean Carroll was one of the first books I read on time. It provided a good framework for thinking about time, introducing to me concepts such as the second law of thermodynamics of entropy. Entropy is a measure of disorder and within a closed system remains neutral or increases over time. An example of entropy is how an egg breaks when drops, you never see it reform itself.

Dr. Carroll also presented the Past Hypothesis, which argues the universe started in a lower entropy state than the present. This characteristic of time defines its asymmetric nature, or in other words, time only goes in one direction as far as we can tell. From this book the idea of an “Entropy Barrier” developed in the manuscript. This concept basically is the point past which life must either devolve or cease to exist. It created a clock for humanity, urgency in the story.

From Eternity to Here: The Quest for the Ultimate Theory of Time
Sean Carroll
Nonfiction
Dutton
October 26, 2010
448
http://www.amazon.com/From-Eternity-Here-Ultimate-Theory/dp/0452296544

Twenty years ago, Stephen Hawking tried to explain time by understanding the Big Bang. Now, Sean Carroll says we need to be more ambitious. One of the leading theoretical physicists of his generation, Carroll delivers a dazzling and paradigm-shifting theory of time's arrow that embraces subjects from entropy to quantum mechanics to time travel to information theory and the meaning of life.

From Eternity to Here is no less than the next step toward understanding how we came to exist, and a fantastically approachable read that will appeal to a broad audience of armchair physicists, and anyone who ponders the nature of our world.