Measuring time with stationary quantum clocks

Abstract

Time plays a fundamental role in our ability to make sense of the physical laws in the world around us. The nature of time has puzzled people -from the ancient Greeks to the present day -resulting in a long running debate between philosophers and physicists alike to whether time needs change to exist (the so-called relatival theory), or whether time flows regardless of change (the so-called substantival theory). One way to decide between the two is to attempt to measure the flow of time with a stationary clock, since if time were substantival, the flow of time would manifest itself in the experiment. Alas, conventional wisdom suggests that in order for a clock to function, it cannot be a static object, thus rendering this experiment seemingly impossible. We show, counter-intuitively, that a quantum clock can measure the passage of time even while being switched off, lending support for the substantival theory of time.

Time and Quantum Clocks: A Review of Recent Developments

“…The formulations presented above are consistent and beautiful. However, the question whether the internal time measured by quantum clocks is affirming the philosophical choice of relatival time (that needs changes to exist) or substantival time (that does not need changes to exist) remains an open question [118].…”

Time and Quantum Clocks: a review of recent developments

“…The formulation presented above are consistent and beautiful. However, the question whether the internal time measured by quantum clocks is affirming the philosophical choice of relatival time (that needs changes to exist) or the substantival time (that does not need changes to exist) remains an open question [93].…”