Thanks Yanniru.

A textbook says energy IS frequency. So is mass = "frequency". (700+ pages, "LIGHT" by Ditchburn)

So a constant of proportionality between energy and frequency IS a constant of proportionality between TWO frequencies. Thus it is a 2-D perspective giving one frequency that relates the two frequencies.

"Time" is how we describe the DIFFERENCE between TWO measurements; in this case comparison of TWO frequencies, two energies, two alternatives involving permutations and combinations.

Planck's constant thus may well be a constant of proportionality between "time" and "energy" from the perspective of ONE of "time" (the difference in energy). In other words, it is about quantum jumps of energy!

There are three ways of looking at it; (1) from the perspective of ONE frequency (energy) and "time" (the difference between the two energies), (2) from the perspective of the new frequency (energy) and "time" (the difference between the two energies), and (3) from the perspective of "time" (the difference between the two energies; so what you say: proportionality between "time" and "energy").

Does that work?

-dolphin