What is the true nature of energy or love?
Don't spend your breath trying to tell,
for no breath could last long enough.
Just tell me how to measure them
and then be so kind and shut-up!
Stan Sýkora, Arese, August 1995
Part of the Perpetuum Mobile physics rhymes:
Like the whole series, this rhyme was stimulated by my sister's query 'What is energy, really?' Since, in essence, all ontological categories are of unfathomable depth, Science can never explain them. At best we can do define them as outcomes of well crafted measurement procedures.