# Evolution of the concept of time in modern physics.

Spavieri G., Sanchez A., Haug E.

Comunicazione
VII - Didattica e storia della fisica
Aula GSSI Ex ISEF - Sala Rossa - Lunedì 23 h 15:00 - 19:00
With special relativity (SR), the absolute time concept of Newtonian physics $(t^{\prime} = t)$ evolves. The constancy of the speed of light requires the transformation $t^{\prime} = \gamma(t$ - $vx/c^{2})$ with relative time and simultaneity because of time dilation and space dependence. Conventionality of the speed of light implies that $t^{\prime} = t/\gamma$ is also viable. Recent advances in the interpretation of the Sagnac effect rule out relative simultaneity and show that relativistic effects and all experiments supporting SR are coherently described only if absolute synchronization and the relative time $t^{\prime} = t/\gamma$ are adopted