In the frame traveling at the speed of light, there is only light, as any activity, fluctuation/vibration, causing change would have to go faster at some part of the cycle, than the frame and thus faster than light, in order cause measureable intervals.

Which goes to my original point, that time is an effect of activity, similar to temperature, which gets modeled as a dimension and correlated with distance, in order to postulate “spacetime.”

Ideal gas laws effectively correlate volume with temperature and pressure, but they are only foundational to our emotions, bodily functions and environment, not the sequence of perception, as thought, that we experience as mobile fauna, navigating our environment.

Change turns future to past. Potential, actual, residual. Tomorrow becomes yesterday, because the earth turns.

There is no dimension of time, because the past is consumed by the present, in order to inform it, aka causality.

Frequencies and amplitudes.