  Martin David Kruskal was one of the most versatile theoretical physicists of
his generation and is distinguished for his enduring work in several different
areas, most notably plasma physics, a memorable detour into relativity, and his
pioneering work in nonlinear waves. In the latter, together with Norman
Zabusky, he invented the concept of the soliton and, with others, developed its
application to classes of partial differential equations of physical
significance.
