The Ultimate Clock

Some will assert that time is a purely human invention. However, there are several biological clocks that are used by organisms to measure time. Apparently the measurement of time elapsed is a critical function of many biological systems. But, no clocks, biological or human made, measure some absolute, universal time. Yet the universe may contain the absolute time measurement.

Many philosophers agree that time is measured in terms of change. If so, there may be an absolute clock. That clock would measure the one absolute, universal change; the velocity of light. That is the change in the position of a photon (regardless of the observer's inertial reference frame). Such a clock would indicate the change in photon position in terms of distance. The movement of photons is the upper limit at which at which energy and information can travel. If photons do not move time does not pass, nothing happens. Moreover, we cannot breathe, think, or perceive. From this perspective the idea of a timeless universe seems untenable.

(A more rigorous discussion would include Lorentz Transforms and common reference points to reconcile inertial reference frames. These point can be considered later.)