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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