London: Aliens may have been trying to contact humans by communicating in a manner similar to Twitter, believe two American researchers.
For almost half a decade, the SETI project has unsuccessfully searched for extraterrestrial life. However, SETI may be looking for the wrong kind of signals from aliens, claim University of California, Irvine, astrophysicist Gregory Benford and his twin, James, a fellow physicist specializing in high-powered microwave technology.
They say there is a better approach to locating aliens.
In two studies appearing in the June issue of the journal Astrobiology, the Benford brothers, along with James's son Dominic, a NASA scientist, examine the perspective of a civilization sending signals into space - or, as Gregory Benford puts it, "the point of view of the guys paying the bill."
The physics professor says: "Our grandfather used to say, ''Talk is cheap, but whiskey costs money''. Whatever the life form, evolution selects for economy of resources. Broadcasting is expensive, and transmitting signals across light-years would require considerable resources."
Assuming that an alien civilization would strive to optimise costs, limit waste and make its signalling technology more efficient, the Benfords propose that these signals would not be continuously blasted out in all directions but rather would be pulsed, narrowly directed and broadband in the 1-to-10-gigahertz range.
"This approach is more like Twitter and less like War and Peace," says
James Benford, founder and president of Microwave Sciences Inc. in
Their concept of short, targeted blips - dubbed "Benford beacons" by the science press - has gotten extensive coverage in such publications as Astronomy Now. Well-known cosmologist Paul Davies, in his 2010 book The Eerie Silence: Renewing Our Search for Alien Intelligence, supports the theory.
This means that SETI, which focuses its receivers on narrow-band input, may be looking for the wrong kind of signals. The Benfords and a growing number of scientists involved in the hunt for extraterrestrial life advocate adjusting SETI receivers to maximize their ability to detect direct, broadband beacon blasts.
But the question remains: where do we look? The Benfords' frugal-alien model points to our own Milky Way galaxy, especially the centre, where 90 percent of its stars are clustered.
Gregory Benford says: "The stars there are a billion years older than our sun, which suggests a greater possibility of contact with an advanced civilization than does pointing SETI receivers outward to the newer and less crowded edge of our galaxy.
"Will searching for distant messages work? Is there intelligent life out there? The SETI effort is worth continuing, but our common-sense beacons approach seems more likely to answer those questions."
First Published: Monday, August 23, 2010, 15:43