Professor Searches for Aliens

Some professors like to communicate with students—others, with aliens.

Physics and Electrical Engineering Professor Paul Horowitz ’65 says he’s convinced that communicating with extraterrestrial life will soon be within scientists’ reach.

Horowitz, who has taught physics at Harvard since 1974, is a leading figure in the official Search for Extra-Terrestrial Intelligence (SETI)—a national project devoted to identifying intelligent life outside our galaxy, with hubs at Harvard and Princeton.

Lounging in his newly renovated office in Jefferson Lab, Horowitz says he is excited about the future of SETI and his own involvement in the search.

“We’re basically asking how would we communicate with these intelligent life forms without going over to [visit] them on a rocket,” Horowitz says.


And he quickly debunks the notion that extraterrestrial life is unworthy of academic investigation.

“They’ve found that at least 100 planets exist outside our solar system. What happened here [on Earth] is probably very typical,” he says. “Somewhere, the magic happens that leads to self-reproducing organisms.”

Horowitz says people first became interested in extraterrestrial life in the mid-19th century.

But he points to the discovery of the radio telescope in the 1960s, which he began working with in the 1970s, as the time when people realized communication over galactic distances might be possible.

The discovery, Horowitz says, seemed the perfect alternative to expensive space travel and past attempts to measure charged particles, which bend in magnetic fields such as those in space.

Beam Me Up

Recent developments, however, have demonstrated the superiority of optical laser SETI over radio—and Horowitz has helped pioneer this technology.

He explains that extraterrestrials are most likely contacting humans by aiming laser beams at receivers on earth. These beams, Horowitz believes, will illuminate their planet or star of origin to a level 5,000 times brighter than the sun.

“When a laser pulse is aimed from a certain star, the star illuminates for a moment so that we can see it,” he explains. “We only do receiving.”

Horowitz says that he and physics graduate student Andrew Howard use a complex optical telescope to search the night sky for such flashes of light. The telescope has sensitive light detectors at its focus and measures five feet across its bottom.