Science fiction author Gregory Benford and his twin brother, the physicist James Benford, say that scientists are tackling the search for intelligent life as if aliens had 1960s-era technology. Here are their suggestions for updating the search for ET.
According to MSNBC, which has a terrific, lengthy article on the brothers' research:
Assuming that aliens would strive to optimize costs, limit waste and make their signaling technology more efficient, Benford and his twin, James a fellow physicist who specializes in high-powered microwave technology suggest the signals would not be steadily blasted out in all directions. Extraterrestrials would be more likely to send narrow "searchlight" beams delivered in pulses.
"This approach is more like Twitter and less like 'War and Peace,' " said James Benford, founder and president of Microwave Sciences Inc., in Lafayette, Calif. The Benford twins, along with James' son Dominic, a NASA scientist, detailed their findings in two studies appearing in the June issue of the journal Astrobiology.
The Benfords suggest a continuous signal blared at thousands of stars would simply cost too much energy. They say aliens might use short bursts say, anywhere from a second to an hour long and point these signals in narrow beams at one star and then another in a cycle involving up to thousands of stars that repeats over days or years.
For civilizations that constantly watch the skies, the bursts would convey enough data to be recognized as undeniably artificial. As observant civilizations concentrated on this simple beacon, other beacons could broadcast more complex data at lower power (assuming the aliens were still pursuing a frugal strategy).
The Benfords suggested looking at a broad range of radio signals in the 1- to 10-gigahertz range, where the travel of light is relatively unimpeded by interstellar matter. Currently SETI is focused on just the 1-to-2 gigahertz region, where components of water such as hydrogen and hydroxyl (a compound of hydrogen and oxygen) emit radio signals.
"The idea is actually based mostly on how all the electronics of the 1960s, when SETI was first starting out, only operated in the range of a few gigahertz," Gregory Benford explained. "Now they operate in a range of up to 100 or 200 gigahertz, so it's a reason to revisit our assumptions. Looking to 10 gigahertz makes sense, since it's cheaper by a factor of 10 to build a transmitter at 10 gigahertz than at 1 gigahertz."
They also point out that we should be scanning the skies 1,000 light years away, in the center of our galaxy, where there's an incredible concentration of older stars that might have developed life long ago. In addition, they consider whether we may already have picked up some alien communications via a radio source that seems to be broadcasting in a 77 minute cycle. The radio signal, called GCRT J17445-3009, comes from an unknown source - it could very well be natural. But if it isn't, say the Benfords, it might actually be aimed at communicating with Earth. Or it might be "one link in an interstellar communications network."
Read the whole article via MSNBC