The Search for Extra-Terrestrial Intelligence Institute (SETI), listening to the cosmos for signs of signals from alien civilizations, may be monitoring the wrong "channels," a U. S. astrophysicist says.

says such a civilization wanting to announce its presence would transmit "cost-optimized" narrowly focused signals,

Gregory Benford of the University of California, Irvine,

not the continuous omni-directional signals the SETI program has been scanning for, a university release said recently.

"This approach is more like Twitter and less like War and Peace," James Benford, Gregory Benford`s twin and fellow physicist, says.

but narrowly directed in the one-to-ten gigahertz broadband signal range and SETI's broad sweeping search could leave many days when brief Twitter-like flashes of "here we are" from alien civilizations go undetected.

"Whatever the life form, evolution selects for economy of resources. Transmitting signals across light years would require considerable resources."

They says alien signals would not be blasted out in all directions

Such short, targeted blips, dubbed Benford beacons, should be the targets of SETI efforts, a growing number of scientists say.

"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."

And the Benfords also suggest concentrating the search on our own Milky Way galaxy, especially its center where 90 percent of its stars are located."The stars there are a billion years older than our sun," Gregory Benford says,