  As 2005, the International Year of Physics, comes to an end, two physicists
working primarily in geophysical research reflect on how geophysics is not an
applied physics. Although geophysics has certainly benefited from progress in
physics and sometimes emulated the reductionist program of mainstream physics,
it has also educated the physics community about some of the generic behaviors
of strongly nonlinear systems. Dramatic examples are the insights we have
gained into the ``emergent'' phenomena of chaos, cascading instabilities,
turbulence, self-organization, fractal structure, power-law variability,
anomalous scaling, threshold dynamics, creep, fracture, and so on. In all of
these examples, relatively simple models have been able to explain the
recurring features of apparently very complex signals and fields. It appears
that the future of the intricate relation between physics and geophysics will
be as exciting as its past has been characterized by a mutual fascination.
Physics departments in our universities should capitalize on this trend to
attract and retain young talent motivated to address problems that really
matter for the future of the planet. A pressing topic with huge impact on
populations and that is challenging enough for both physics and geophysics
communities to work together like never before is the understanding and
prediction of extreme events.
