The Physics and Philosophy behind Cosmic Time

How far back in time can we have knowledge of the universe? Most cosmologists would agree that the physics describing the ‘material content’ of the universe becomes increasingly speculative the further we go back in time. By contrast, it is widely assumed that the concept of time itself – by virtue of the cosmological standard model – can be safely extrapolated sixty orders of magnitude back from the present to the Planck time. However, certain physical and philosophical assumptions (involving e.g. the so-called Weyl principle and the nature of time) must be made in order to set up the cosmological standard model with a global time parameter. In this talk, I will discuss how the physics which supposedly describes the very early universe – and in particular the supposed quantum nature of matter at this ‘epoch’ – may undermine these assumptions and hence question the very definition of cosmic time.


17/02/2011 - 13:00
Henrik Zinkernagel
Universidad de Granada