Time's Arrow: 2nd Law applies (General)

by dhw, Saturday, October 01, 2016, 12:26 (2974 days ago) @ David Turell

QUOTES: The Second Law of Thermodynamics does imply a direction. The Second Law states that over time, everything moves from an ordered state to a disordered state. It's the only physical law that can't go backwards.-The universe, like an unmixed cup of coffee, started in an extremely ordered state. Over time, the universe mixed together and became less ordered, like what happens when you stir the coffee. Going back in time is unmixing; it can't be done. The universe can't be 'unmixed'.-"What this means, ultimately, is that time only exists because the Big Bang created a universe that started out ordered. If the universe was disordered from the beginning, there would be nothing left to mix and time would not exist. This also means that someday in the far distant future, once everything in the universe gets mixed for good, time will disappear completely."-I think most of us would agree that our own solar system is in such good order that it allows life, which itself demands an astonishingly ordered system. Does Sean Carroll honestly believe that our ordered solar system and life itself were present at the moment of the Big Bang (if it happened)? The order of our solar system and of life itself is the result of mixed ingredients, and the fact that we can't reverse the order of events that have happened is irrelevant. As far as this naïve non-physicist is concerned, the history of the universe appears to show an ongoing sequence of disorder - order - disorder. Yes, all order moves to a disordered state, but order appears to have arisen out of disorder (e.g. disordered individual components without life are combined into an order that gives life). This means that there is a continuous process of cause and effect, of before and after, in which case the only way time will disappear is if the universe itself disappears and there is absolutely nothing left.