  Temperature is an outsider in the laws of motion given by Newton and Einstein
and this oversight is the source of the predictions of time-reversal-invariance
made by these two great systems of motion. By taking into consideration
Planck's law of blackbody radiation and the Doppler effect, in thinking about
Maxwell's electromagnetic wave equation, I have shown that photons, in the
environment through which any charged particle moves, act as a source of
temperature-dependent friction on everything from elementary particles to
galaxies. Because the optomechanical friction is universal and inevitable, no
real systems are conservative, and temperature can no longer be an outsider in
a fundamental and irreducible law of motion. I have defined the change of
entropy (\Delta S) in irreversible systems at constant temperature in terms of
the optomechanical friction. The Second Law of Thermodynamics, which states
that \Delta S > 0 for spontaneous processes, is explained by electromagnetic
interactions between charged particles and the Doppler-shifted photons through
which they move as opposed to chance and statistics. \Delta S, as defined here,
is not subject to Poincar\'e's recurrence theorem. Consequently, the Second Law
of Thermodynamics is shown to be a fundamental law rather than a statistical
law. This result, which supports the idea that every instant of time is unique,
is consistent with intuition and the routine experience of botanists.
