11 May: Richard T.W. Arthur (McMaster University) – “Local Time Flow and Relativity”
Sala Seminari, Via Festa del Perdono 7, h. 14.00-16:00.
Abstract: In this paper I give a sample of some of the main arguments in my forthcoming book, The Reality of Time Flow: local becoming in modern physics, pertaining to becoming in a relativistic context. I argue, (in company with Dieks and Savitt), that one of the less appreciated implications of relativity theory is that becoming is a local phenomenon. That is, the classical conception of becoming as tied to a plane of simultaneity must be abandoned in favour of a conception of process as taking place along world-lines (time-like lines in spacetime). Time lapse—how fast anything ages or changes—is tracked by proper time, and not coordinate time. This results in different lapses of time for different paths through spacetime, as in the twin paradox; clocks also run faster at higher field potentials in gravitational fields, meaning that time lapses unevenly throughout the universe. On the other hand, no plane of simultaneity is definable for a rotating observer in spacetime.