October 24, 2013 - The theory, proposed by James
Benford, his son, Dominic Benford, and Jame's twin brother Gregory Benford, published in two papers in June, have generated a great deal of excitement in the science world. The Benfords looked at the issue of communications and concluded that aliens, much like humans, would want to economize their resources where possible, and thus they would not send out communications resembling what scientists
have expected would be sent. Instead, the scientists suggest, aliens might be as frugal with expensive resources as humans are.
The University of California Irvine said extraterrestrials might have been trying to contact Earth all along, but because scientists were looking for something different, the messages were missed. The trio of scientists believe extraterrestrials might send out short messages, or pulses. James explained, saying “This approach is more like Twitter
and less like War and Peace.”
James is a physicist as well as the founder and president of Microwave Sciences Inc. in Lafayette, California. Dominic is a scientist with NASA, and Gregory is an astrophysicist with the University of California Irvine.
The new hypothesis is based on an old adage. Gregory explained “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.”
SETI (Search for Extraterrestrial Intelligence) has been searching for extraterrestrials for the past fifty years, trolling for signals from space with arrays of satellite dishes. The Benfords hypothesize "Assuming that an alien civilization would strive to optimize costs, limit waste and make its signaling technology more efficient, ... 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."
James summarized their hypotheses and findings during an interview with New Scientist. "If ET was building cost-effective beacons, would our searches have detected them? The answer turns out to be no. Societies are always constrained by their resources. Why did cathedrals take centuries to build? Partly because they had only so many artisans, but also their capital was limited."
James explained the hypothesis to the New Scientist
"Short pulses rather than a continuous signal would also enable frugal aliens to use small and cheap transmitters. Small transmitters can beam out powerful radiation using high voltages – but only if they broadcast brief pulses that don't give the electric fields time to discharge.
They wouldn't want to target individual stars: there are far too many of them. Instead, they'd build a powerful beacon, then swing that beacon around and repeat it.
Astronomers have seen some unexplained signals that lasted for tens of seconds then were never seen again. Some of those could have been extraterrestrial beacons but there wasn't enough observing time to wait for any repeats."
The Benfords suggest SETI should point its receiver dishes towards the center of the milky way because the stars are denser there. Gregory said “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."
The short pulse approach to communications has cottoned on quickly, with science writers calling the theory Benford beacons. The hypothesis has also meant that many are speculating that the WOW signal, found in 1977, might actually be an alien tweet. The signal was dismissed as a 'cosmic burp.'
Gregory said “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.” The real answer, of course, will be revealed as scientists test the hypothesis.
The Benford's theory has been endorsed by other scientists.
The trio's hypotheses were written up in two papers, Searching for Cost-Optimized Interstellar Beaconsand Messaging with Cost-Optimized Interstellar Beacons, both of which were published in Astrobiology in June.