July 22: In what sounds like a Hollywood science fiction script, scientists say aliens could have been using “cosmic tweets” to contact humans on earth for decades unsuccessfully. While any “lost in space” messages wouldn’t exactly be restricted to 140 characters, as it is with the micro-blogging site Twitter, a study suggested that aliens are more likely to send out short, directed messages than continuous signals beamed in all directions, the Daily Mail reported.
“This approach is more like Twitter and less like War and Peace,” said Dr James Benford, a physicist and president of Microwave Sciences. His twin brother Gregory, an astrophysicist at the University of California, added: “Whatever the life form, evolution selects for economy of resources.
“Transmitting signals across light years would require considerable resources.” The brothers, who looked at the search for another life form in the galaxy from the alien’s point of view, concluded that scientists involved in America’s Search for Extra-Terrestrial Intelligence may have been taking the wrong approach for five decades. Writing in the journal Astrobiology, the Benfords said alien signals would not be blasted out in all directions but narrowly directed in the one to 10 gigahertz broadband signal range.
SETI’s search is like a lighthouse sweeping the galactic plane, say the brothers, but that could leave many days when brief Twitter-like bursts of “here we are” flashes from alien civilisations go undetected. The duo said the SETI scientists’ strategy involves listening out for unusual bleeps from targeted nearby stars. But they should be aiming at the centre of the galaxy instead, said the Benfords. “The stars there are a billion years older than our sun, which suggests a greater possibility of contact with an advanced civilisation than pointing SETI receivers outward to the newer and less crowded edge of our galaxy,” said Gregory Benford.