Improbability Drive: Focus on rare actions speeds chemical simulations

In The Hitchhiker’s Guide to the Galaxy, the book by Douglas Adams, a machine made interstellar travel possible by nudging nature toward extremely improbable, but not impossible, events. A new computer-simulation technique promises to calculate chemical-reaction rates 20 times as fast as before by focusing on chains of events that—on the timescales of molecular motion—are very rare but important.