[1] Other areas he made contributions to include percolation theory and the Wiener sausage.

His book Principles of Random Walk, first published in 1964, remains a well-cited classic.

[1] During the war years, Spitzer's parents and his sister were able to make their way to the United States by passing through the unoccupied parts of France and North Africa, and, after the war, Spitzer joined his family in their new country.

After completing his military service in 1947, Spitzer entered the University of Michigan to study mathematics.

[2] A multi-year struggle with Parkinson's disease culminated Spitzer's retirement from Cornell in 1991,[3] at which point he became a professor emeritus.