David Elder Lecture - Dr Setnam Shemar presents 'Time and Space: From Atomic Clocks and Cosmic Clocks to Testing Einstein’s Relativity'

Time lies at the heart of our understanding of the Universe.

From the motion of the stars to the world's most accurate atomic clocks, the ability to measure time ever more precisely has transformed astronomy, navigation and fundamental physics.In this lecture, Dr Setnam Shemar of the National Physical Laboratory explores how both human-made atomic clocks and nature's own cosmic clocks—pulsars—have enabled remarkable discoveries, from the first exoplanets to increasingly precise tests of Einstein's theory of relativity.

The journey culminates with the Atomic Clock Ensemble in Space (ACES), one of the most ambitious precision-timing experiments ever flown in orbit, opening a new era in our exploration of time, gravity and the Universe.