The feature article “Chaos at Fifty” by Adilson Motter and David Campbell highlights Edward Lorenz’s discovery1 in 1963, which, the authors say, “gave birth to a field that still thrives.” Without a doubt, Lorenz’s contribution was outstanding, but the real history of the scientific research of chaos starts with Boris Chirikov a few years earlier. Work done by Chirikov in 1959 established a resonance overlap criterion for the onset of chaotic motion of plasma confined in a mirror magnetic trap.2The criterion was later shown to also apply to a number of other deterministic Hamiltonian systems, and it is now known as the Chirikov criterion.
Over the ensuing decades, Chirikov made a great many seminal contributions to what became known as the field of chaos.3 (See also his obituary in Physics Today, June 2008, page 67.) It would be a shame if readers of the magazine forgot about this pioneer of chaos.
