Lester Ford

Lester Randolph Ford Jr. (1927–2017) was an American mathematician who worked at the RAND Corporation during the golden age of a brand-new subject: how to move things — data, goods, traffic — through a network as cheaply as possible. Confusingly, his father was also a well-known mathematician named Lester Ford, so the two are often mixed up.

The famous work

Ford's name lives on in the Bellman–Ford algorithm, a shortest-path method that, unlike some rivals, can cope with negative edge weights and can even detect impossible "negative loops." He developed it around the same time as Richard Bellman, which is why they share the credit. With his colleague Fulkerson he also created the celebrated max-flow min-cut theorem, a cornerstone of network optimisation.

Because father and son were both mathematicians called Lester R. Ford, their papers get tangled together to this day. The elder Ford is remembered for the elegant "Ford circles" in number theory; the younger for networks and flows. Working side by side with other RAND researchers in the 1950s, the younger Ford helped turn the abstract idea of a network into practical algorithms that now route your data across the internet every second.