Retrocausality…

by danjo

Physics at its coolest: From the New Scientist we learn that something called retrocausality might be possible. Scientists are figuring out how to measure if the universe is going all Star Trek on us. But what I liked best was the more philosophical speculations on what this means for the origin of the laws of nature. From the end of the article:

Paul Davies, a theoretical physicist at the Australian Centre for Astrobiology at Macquarie University in Sydney, suggests another possibility: the universe might actually be able to fine-tune itself. If you assume the laws of physics do not reside outside the physical universe, but rather are part of it, they can only be as precise as can be calculated from the total information content of the universe. The universe’s information content is limited by its size, so just after the big bang, while the universe was still infinitesimally small, there may have been wiggle room, or imprecision, in the laws of nature.

And room for retrocausality. 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 favourable for life. This may seem circular: life exists to make the universe suitable for life. If causality works both forwards and backwards, 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,” 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.”

Is this where Aristotle wakes up, laughs in our faces, and says ‘Told you so: Telos!’?

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