Is time a measure of such activity, or is such activity a feature of this underlaying "dimension" called "time?'

All the experiments and clocks would seem to assume it is a measure of activity, yet the belief remains of this underlaying dimension.

If it is only a measure of the activity itself, then it is actually similar to temperature, pressure, color and sound, rather than space. Frequencies and amplitudes. Time is frequency, events are amplitude.

The confusion seems to be that as these mobile organisms, our experience of reality is as a sequence of perceptions, so our concept of time is as the point of the present, moving past to future, as opposed to change turning future to past. Tomorrow becomes yesterday, because the earth turns.

Ideal gas laws correlate volume with temperature and pressure, but we don't consider them dimensions of space, because they are only fundamental to our emotions and bodily functions, not the sequence of thought.

As this article makes clear, different clocks can run at different rates simply because they are separate actions. Think metabolism. It is synchronizing them that's hard.

Time is asymmetric because action is inertial. The earth only turns one direction.

There isn't any literal "dimension" of time, since the past is effectively consumed by the present, to inform and drive it. Causality and conservation of energy. Cause becomes effect. Potential, actual, residual.

Energy is "conserved," because it creates time, so there is no past for it to be lost in, nor future from which it arrives. As process, it goes past to future, while the patterns generated go future to past.

With waves, the energy drives it, while the fluctuations rise and fall. Energy to the future, information to the past.

As consciousness goes past to future, while thoughts go future to past. Though it is our digestive, respiratory and circulatory systems processing the energy, while the central nervous system sorts the information, signals from the noise. So the tendency to see reality in terms of order and disorder, rather than energy and form.

Science and philosophy from a philosopher's perspective.