There's also the idea of timeless physics, as argued in https://en.wikipedia.org/wiki/Julian_Barbour#Timeless_physics https://en.wikipedia.org/wiki/Julian_Barbo

There's also the idea of timeless physics, as argued in https://en.wikipedia.org/wiki/Julian_Barbour#Timeless_physics https://en.wikipedia.org/wiki/Julian_Barbour#Timeless_physic... or in slightly different form in http://lesswrong.com/lw/qp/timeless_physics http://lesswrong.com/lw/qp/timeless_physics It's apparently possible to rewrite all physical equations without time coordinates and they still work. I'm not competent enough to understand all of it and to check if it's not contradicting any experiments, but I'd love to hear if it does. It seems particularly elegant (because if the state of the universe can't repeat, then why do we need time?).