Now, I don't really get this, but reading the New Scientist last week, my eye was caught by an article on retrocausality (the full article is up on the Google alt.philosophy list):
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.
Researchers are on the verge of experiments that will finally hold retrocausality's feet to the fire by attempting to send a signal to the past. What's more, they need not invoke black holes, wormholes, extra dimensions or other exotic implements of time travel. It should all be doable with the help of a state-of-the-art optics workbench and the bizarre yet familiar tricks of quantum particles. If retrocausality is confirmed - and that is a huge if - it would overturn our most cherished notions about the nature of cause and effect and how the universe works.
Kathryn Cramer mentions this on her site with regard to a Gedankenexperiment that her father, John Cramer, who is quoted in the New Scientist piece, "proposed in a talk he gave at an AAAS meeting in San Diego last June."
Then, yesterday, listening to the BBC's Start the Week, "eminent physicist and cosmologist Paul Davies" (author of The Goldilocks Enigma: Why is the Universe Just Right for Life?) mentioned it again. (I'm always nervous when physics approaches philoshopy which is why I'm interested to read Bernard d'Espagnat soon-to-be-released On Physics and Philosophy.)
Anyone know what else I should be reading to help explain this to myself!?