Time really exists! The evolving block universe


George Ellis

Department of Mathematics, University of Cape Town, Rondebosch 7701, Cape Town, South Africa.


Euresis Journal, volume 7 (2014), pages 11-26

My starting point is the question, did it make sense for the Planck team to announce the present age of the universe? This talk will propose that it did, because spacetime is an evolving block universe, with the present being the boundary of a spacetime which steadily extends into the future as tiem progresses. The present separates the past (which already exists) from the future (which does not yet exist, and is indetermate because of foundational quantum uncertainty). There are some technical apsects to this - namely (1) simultaneity has no physical importance, it is a purely psychological construct, (2) one can define unique surfaces of constant time in a non-local geometric way (and show this relates to the standard ADM formalism), (3) this proposal solves the chronology protection problem (it prevents exietnce of closed timelike line). In this context, (4) the arrow of time is distinguished from the direction of time, which is non-locally defined in the evolving block universe context.