If I Could Turn Back Time

Cher might be dismayed by the preliminary conclusions drawn from a (comparatively) nano-scale re-creation of the birth of the universe. It's complicated, but it seems that they found that, since plasmons seem to follow the second law of thermodynamics, they can't trace an organized enough route to travel back over their own path. Of course, this is all complete conjecture and is already being challenged. http://news.nationalgeographic.com/news/2011/04/110427-time-travel-not-possible-physics-big-bang-space-science/