Real title but couldn't fit it in subject:
Science hopes to change events that have already occurred"Ever wish you could reach back in time and change the past? Maybe you'd like to take back an unfortunate voice mail message, or rephrase what you just said to your boss. Or perhaps you've even dreamed of tweaking the outcome of yesterday's lottery to make yourself the winner.
Common sense tells us that influencing the past is impossible -- what's done is done, right? Even if it were possible, think of the mind-bending paradoxes it would create. While tinkering with the past, you might change the circumstances by which your parents met, derailing the key event that led to your birth.
Such are the perils of retrocausality, the idea that the present can affect the past, and the future can affect the present. Strange as it sounds, retrocausality is perfectly permissible within the known laws of nature. It has been debated for decades, mostly in the realm of philosophy and quantum physics. Trouble is, nobody has done the experiment to show it happens in the real world, so the door remains wide open for a demonstration."
"If it exists, the presence of conscious observers later in history could exert an influence on those first moments, shaping the laws of physics to be favorable for life. This may seem circular: Life exists to make the universe suitable for life. If causality works both forward and backward, however, consistency between the past and the future is all that matters. "It offends our common-sense view of the world, but there's nothing to prevent causal influences from going both ways in time," Paul Davies says. "If the conditions necessary for life are somehow written into the universe at the Big Bang, there must be some sort of two-way link."Link:
http://www.sfgate.com/cgi-bin/article.cgi?f=/c/a/2007/01/21/ING5LNJSBF1.DTLBlacknad.
