From Eternity to Here
Delicious Link
The arrow of time points in one direction only, from past to present to future. Now there's a fact—rather like Wittgenstein's observation "A is the same thing as A"—that is so patently obvious as to be unworthy of remark. But ask a theoretical physicist just how obvious that fact really is and you will soon discover that it is not obvious at all. Indeed the "arrow of time" presents one of the greatest mysteries known to modern science. Why so? Well, for a start, no one can agree on what precisely is meant by "past," "present" and "future." As for an agreed definition of "time" itself, we are as far as we have ever been from achieving that.
Original Link: http://online.wsj.com/article/SB10001424052748703436504574640151374207392.html?mod=WSJ_Opinion_TOPRightCarousel
