The classical harmonic oscillator is a model system that
has a history of more than a hundred years in the scientific
literature and that is discussed in every first-year course in
physics. Its has achieved the status of a paradigm because it
describes the behavior of a wide variety of systems in physics,
chemistry, biology, and other fields. To quote Gitterman [1],
“In fact, it has been applied everywhere, from quarks to
cosmology.” Examples include mechanical systems such as
pendula with small angles of displacement and mass-spring
systems, acoustical systems and electric systems such as RLC
circuits, as well as man-made devices such as clocks and
radio circuits. The prominence and importance of this model
stem from the fact that the dynamics of any system in a
potential near a local minimum can be approximated by simple
harmonic motion. The harmonic oscillator still holds surprises
and remains the object of current research despite its long
history.
If friction or energy dissipation has to be taken into account,
one arrives at the damped harmonic oscillator where the forces
are linearly proportional to the displacement from the local
minimum and to the velocity: