On the global existence of time

Abstract

The existence of a global time is often taken for granted but should instead be considered as a matter of investigation. By using the tools of global Lorentzian geometry I show that, under physically reasonable conditions, the impossibility of finding a global time implies the singularity of spacetime.

11 pages, 3 figures. Third juried prize at the FQXi contest "The nature of time". In this version some misprints have been fixed, and some references have been updated

References in corpus (4)

• K-causality coincides with stable causality
• Chronological spacetimes without lightlike lines are stably causal
• The causal ladder and the strength of K-causality. II
• Universal one-way light speed from a universal light speed over closed paths

Cited by in corpus (3)

• Expanding space, quasars and St. Augustine's fireworks
• Augustine of Hippo's philosophy of time meets general relativity
• Causal Stability Conditions for General Relativistic Spacetimes