Cipra, Barry, What goes around comes around, Science 255 (6 March 1992) 1212-1213.
"[I]f Arnold Schwarzenegger crushes a basketball, how many unbroken rubber bands can Magic Johnson wrap around it?" In mathematical terms: "How many closed geodesics are there for any Riemannian metric on a sphere?" The answer-infinitely many-is the joint work of John Franks (Northwestern University) and Victor Bangert (University of Freiburg); their collaboration represents the introduction of methods from dynamical systems into differential geometry, an idea that may prove even more fruitful in the future.
This review was reprinted with permission from Mathematics Magazine, June 1992 issue.