SETI award honors laser laureate Townes

The Search for Extra Terrestrial Intelligence (SETI) Institute (Mountain View, CA) has awarded the 2002 Frank Drake Award for Innovation in SETI and Life in the Universe Research to Charles H. Townes, Nobel laureate and emeritus professor of physics at the University of California Berkeley. Townes received the award for his championing of optical SETI—efforts that culminated in the formal adoption of optical SETI as a search strategy by SETI scientists.

Townes is the second recipient of the Drake Award, which honors distinguished contributors to the scientific search for life beyond Earth. The first award was presented in 2001 to Drake, the chairman of the board of the SETI Institute and the oft-proclaimed "Father of SETI." Townes is the first honoree selected from a pool of candidates whose submissions were solicited by the Institute.

"I am very happy to see multiple optical SETI projects undertaken with the same rigor SETI scientists have applied to radio searches,'' said Townes. "It was gratifying to participate in planning sessions that led to today's large-scale optical SETI searches, and I am pleased by this recognition from the world's leading SETI research organization."

Townes' principal scientific work is in microwave spectroscopy, nuclear and molecular structure, quantum electronics, radio astronomy, and infrared astronomy. He holds both the original patent for the maser (with James Gordon) and the laser (with Arthur Schawlow). He received the 1964 Nobel Prize in Physics for his work in quantum electronics, which led to the construction of maser and laser oscillators and amplifiers.

Townes envisioned using the infrared and optical spectrum for SETI in 1959 after reading a seminal paper in the journal Nature theorizing the possibility of using radio waves to communicate across interstellar space. Townes first proposed searching the optical spectrum for extraterrestrial signals in 1961, one year after Frank Drake started the first scientific SETI search of the radio spectrum.

Acknowledging that radio technology matured more quickly than optical, Townes consistently maintained that other technologically advanced civilizations could exploit the optical and infrared spectrum for communications just as readily as the microwave spectrum. In two papers published in 1982 and 1993, Townes compared the relative strengths and liabilities of optical and radio SETI, concluding that both research methods should be conducted.

By the late 1990s, laser technology had matured to the point at which sensitive and accurate searches in the optical spectrum became practical. Townes' participation in a SETI research-planning panel galvanized researchers Paul Horowitz of Harvard and Dan Werthimer of the University of California (UC) to initiate optical SETI searches at their institutions.

Today, numerous scientific teams are searching optical data for SETI beacons. In one project funded by the SETI Institute, Drake and scientists from UC-Santa Cruz, UC-Berkeley, and Lick Observatory (Mt. Hamilton, CA) are looking for brief but powerful laser light pulses beamed our way from extra-solar planetary systems, rather than the steady noise from a radio transmitter. The Lick Observatory's 40-in. Nickel Telescope is coupled with a new pulse-detection system capable of finding laser beacons from civilizations many light-years distant.

"One great advantage of optical SETI is that there's no terrestrial interference," notes Drake. "It's an exciting new field."