"What comes first?" is critically important when computer processors perform operations that rely on each other's outputs. Leslie Lamport realized this when reading a 1975 paper by Paul Johnson and Robert Thomas proposing timestamps to track the sequence of events in a distributed algorithm.
"I immediately related that to special relativity," Einstein's theory of space-time, says Lamport, principal researcher at Microsoft Research and recipient of the 2013 ACM A.M. Turing Award. "The notion of 'at the same time' is relative. It's not an invariant notion. But what is invariant is the notion of causality." Lamport will receive the $250,000 Turing prize for his work in bringing order to the chaos of distributed computing systems that rely on communication between many autonomous computers.