Department of Physics and St.
John’s Society of Physics Students Chapter
Behind Tsunami and More
Dr. Peter S. Riseborough
Department of Physics, Temple University
In 1968 Zabusky and Kruskal examined the continuum limit of the
problem numerically, in which the number of atoms is increased and
the spacing between the atoms is reduced so that it looks like a
continuous string. They found that this system was described by a
partial differential equation first put forward by two dutchmen
Korteweg and de Vries (KdV) to describe unusual waves in shallow
canals. These unusual water waves were first observed by Scott
Russell while inspecting a canal near Edinburgh.
These solitary waves had a localized profile (like a Tsunami),
but unlike most other water waves never broke or changed form.
Zabusky and Kruskal found that when these special waves collided
they passed through each other. Zabusky and Kruskal penned the name
soliton to describe these particle-like wave excitations.
Zabusky and Kruskal's result spurred intensive studies by
mathematical physicists who showed that the continuum system was
governed by an infinite number of conservation laws. It was also
found that the KdV equation supported very unusual oscillations
that were localized. Recently it has been proposed that excitations
like these have been found in experiments that look at the lattice
dynamics of a three-dimensional structure: rocksalt.
All interested students and faculty are invited. Refreshments
will be served.