Michele Henon is an astronomer
at
the Nice Observatory in southern France. For many years, during the 1960's
particularly, he studied the dynamics of stars moving within galaxies,
using computers as a way to understand the stability of their motions.
His work was very much in the spirit of
Poincare
's
approach to the classisical
three-body problem: What important geometric structures govern their
behavior?
The main property of these systems is that the energy of their motion
is constant, to very high approximation. As a consequence, their chaotic
dynamics are not described by simple attractors, but by objects that are
markedly more difficult to analyze and visualize, existing on energy "surfaces"
in three and higher dimensions.
During the 1970's he discovered a very simple iterated mapping that
show a chaotic attractor, now called Henon's attractor, that allowed him
to make a direct connection between
deterministic chaos
and
fractals
. The
Henon attractor is self-similar. If you zoom in on the attractor in its
state space you find more and more layers, much like filo dough or a croissant.
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