Posted on 07/23/2010 9:42:39 AM PDT by null and void
Astrophysicist Gregory Benford standing before the UCI Observatory believes an alien civilization would transmit cost-optimized signals rather than the kind sought for decades by the SETI Institute. Courtesy of Steve Zylius
For 50 years, humans have scanned the skies with radio telescopes for distant electronic signals indicating the existence of intelligent alien life. The search centered at the SETI Institute in Mountain View, CA has tapped into our collective fascination with the concept that we may not be alone in the universe.
But the effort has so far proved fruitless, and the scientific community driving the SETI project has begun questioning its methodology, which entails listening to specific nearby stars for unusual blips or bleeps. Is there a better approach?
UC Irvine astrophysicist Gregory Benford and his twin, James a fellow physicist specializing in high-powered microwave technology believe there is, and their ideas are garnering attention. In two studies appearing in the June 2010 issue of the journal Astrobiology, the Benford brothers, along with James 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.
Our grandfather used to say, Talk is cheap, but whiskey costs money, the physics professor says. 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 optimize costs, limit waste and make its signaling 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 in Lafayette, CA.
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 where to look? The Benfords frugal-alien model points to our own Milky Way galaxy, especially the center, where 90 percent of its stars are clustered.
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, Gregory Benford says.
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.
Ping worthy?
Whatever private funding they can get is fine, but I think they´re going to be listening for a long, long time.
Yes, perhaps they will.
Is there really intelligent life on other planets?
Just the theological implications of the answer are astounding.
Either way.
Seems to me these guys are assuming that we should look only for ETs who are intentionally announcing their presence. Not sure if that is because we don’t want to find anyone who isn’t, or if they believe that we would only be able to find those who want to be found, or what.
It’s the equivalent of a drunk looking for his keys under the streetlight, because that’s where the light is better.
Mostly if someone isn’t deliberately trying to get a message through, any accidental emissions will be lost in the cosmic background noise.
At some point we may have sensitive enough receivers to pick up a faint leakage signal, and the computational ability to extract it from all the other random noise, but not today.
I’m not so sure we actually want to talk to anyone dumb enough to advertise their existence in a universe potentially filled with predators...
And if we are trying to spot random leakage of their internal radio communications, good luck with that. We were broadcasting straight analog signals only for a few decades, and now we're already switching to spread spectrum, compressed and encrypted digital signals, etc. There will never be enough signal to noise ratio to pick that kind of data up over cosmic distances. The chances that we are looking at a star just in those few decades (out of millions of years) when the signals are analog and intelligible would make winning the top prize in the powerball lottery seem like a daily event.
Pretty much. Still the powerball lottery does occasionally get won.
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