What is the difference

Between your time and my time

Asks a father to a son

Mass and energy balance

Replies the son

In a discussion of time

From where comes

The first course I taught, asks the father

Principles of the course you taught haven’t changed

Interpretations have, says the son

Inputs have always been suitably rewarded

Be it in your time, be it in my time

Inputs have changed their meaning over time

Expectation of one from the other is losing shine

The modus operandi has changed

Minimization of loss is still the operating principle of

Mass and energy balance

Tells the son to a proud father