Mountain climbing problem

In mathematics, the mountain climbing problem is a mathematical problem that considers a two-dimensional mountain range (represented as a continuous function), and asks whether it is possible for two mountain climbers starting at sea level on the left and right sides of the mountain to meet at the summit, while maintaining equal altitudes at all times. This problem was named and posed in this form by James V. Whittaker (1966), but its history goes back to Tatsuo Homma (1952), who solved a version of it. The problem has been repeatedly rediscovered and solved independently in different contexts by a number of people (see references below).

Since the 1990s, the problem was shown to be connected to the weak Fréchet distance of curves in the plane, various planar motion planning problems in computational geometry, the inscribed square problem, semigroup of polynomials, etc. The problem was popularized in the article by Goodman, Pach & Yap (1989), which received the Mathematical Association of America's Lester R. Ford Award in 1990.