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Published online: 06 September 2004; | doi:10.1038/news040906-3
muse@nature.com: Waiting for ETPhilip BallRumours
of contact with aliens have been exaggerated (again). Philip Ball asks
whether the search for extraterrestrials does anything but fuel
paranoia.
| SETI telescope collects data to enable research in the areas of astronomy, planetary studies, space and atmospheric sciences. |
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Those
aliens... we just cannot figure them out. Just as we decide they are
more likely to mail us than to radio us, they go ahead and beam us a
message anyway. Maybe their copies of Nature aren't reaching them quickly enough.
On 2 September, Christopher Rose and Gregory Wright pointed out in Nature
that, bit for bit, it is far more energy-efficient to send messages to
other worlds as nanoscribed parcels than as encoded electromagnetic
signals1. Yet that week also saw excited
accounts in the press that claimed the SETI@home project had just
reported its "most interesting signal" so far, coming from between
Pisces and Aries at a frequency of 1420 megahertz. The project is the
arm of the Search for Extraterrestrial Intelligence in which volunteers
use their home computers to sift through radioastronomy data for signs
of intelligent broadcasts.
Within hours of the first report, in New Scientist magazine, the news wires were humming. "Could space signal be alien contact?" asked Reuters. Britain's Daily Telegraph didn't mince its words: "Scientists tune in to 'radio message from the aliens'."
 It's all hype and noise  |
Dan Werthimer
SETI chief scientist |
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But
the SETI Institute scientists themselves are not jumping up and down
about the signal, which they believe is most likely to be due to random
noise. And they are not at all happy about the press attention. "It's
all hype," says SETI chief scientist Dan Werthimer. "We have nothing
that is unusual. It's all out of proportion."
Damping down
It
is a familiar pattern: although scientists in many fields can only
dream of attracting so much attention, SETI researchers spend their
time struggling to bring everyone else back down to earth. But then,
those involved in SETI probably have lower expectations of their
studies than any other researchers on the planet. Failure is precisely
what they anticipate. "We shouldn't have succeeded yet," cautioned
astronomer and SETI senior scientist Frank Drake last month.
You
could say Drake started the whole enterprise: he conducted the first
ever radio search for alien intelligence back in 1960. His name is
familiar from his famous equation for estimating the number of
civilizations in our galaxy that are trying to communicate with us. To
Drake, the equation was merely a formalized way of showing all the
things we do not know. (It involves multiplying together a number of
factors including the fraction of habitable planets on which
intelligent life evolves, and the chances of those civilizations
wanting to communicate with others.)
| We shouldn't have succeeded yet |
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He
drew up the equation simply as a way of organizing the discussions
about extraterrestrial intelligence that took place in 1960 at the
radio observatory in Green Bank, West Virginia. This was a meeting of
visionaries, including Carl Sagan, physicist Philip Morrison and
biochemist Melvin Calvin. The previous year, in Nature, Morrison and
his colleague Giuseppe Cocconi had proposed the idea of searching the
skies for alien messages2, and Drake, with Sagan and others, went on to found the SETI Institute in 1984.
The
Drake equation has become a touchstone of SETI efforts. But, as with so
many things in this area, it has been interpreted far beyond its
intended use. It is regularly quoted as if it were a formal proposal,
and searching for aliens were a quantifiable science.
Fool's gold?
Debates
about the value of SETI tend to be dominated by extremes: the cynics
who deride it as a fool's quest, and the prophets who portray it as the
most philosophically profound venture imaginable. What is clear is that
SETI does not need anything in the way of results to capture the public
imagination: Jill Tarter, the SETI scientist who provided the model for
Jodie Foster's character in the movie Contact, was voted one of Time
magazine's top 100 "people of power and influence" this year.
SETI's
defenders point out that it costs nothing. The SETI Institute in
Mountain View, California, is privately funded and the Allen Telescope
Array currently under construction in California, which will carry out
standard radioastronomy as well as SETI searches, is being supported by
a US$13.5 million donation from Microsoft cofounder Paul G. Allen. And
in terms of getting school children interested in science, searching
for aliens beats even dinosaurs.
Of
course, if Rose and Wright are correct, SETI may not be going the right
way about its search. An alien civilization that wants simply to say
"look over here" might indeed use electromagnetic signals. But if it
wanted to tell us anything about itself, it would send out messages in
bottles, or inscribed on giant black tablets in the hope that they
would be discovered floating around Jupiter to the strains of Also Sprach Zarathustra.
But
the project has a far more fundamental problem: it is trying, in good
faith, to do science in an area where every false alarm is likely to
become hot news, blown far out of proportion. When Britain's BBC runs a
headline like "Astronomers deny ET signal report", as it did last
Thursday, you can hear the conspiracy engines start running. Well they
would say that, wouldn't they? They've probably been chatting with the
Pisceans since Christmas.
Perks for the paranoid
Seth
Shostak, SETI's senior astronomer, admits that the interest raised by
false alarms is a problem. The poor man receives an unenviable stream
of emails. "Check out the Pleiades," advises one correspondent, who has
presumably figured out that would be a cosy part of the universe for
aliens to live. Another reckons that the Sirius system is the best bet,
because "the Dogon (a tribe in Mali) were visited by aliens who told
them about the white dwarf star that orbits Sirius A". Other
suggestions include tuning the receiving equipment to the wavelength of
"brain transmissions" (but at what wavelengths do alien brains
transmit?).
All
this, like the furore over the latest 1420-megahertz signal, is
scarcely SETI's fault. But it does raise the question: can a quest like
SETI ever be conducted without fuelling the paranoid conviction, which
has attained epidemic proportions in its host country, that the aliens
have found us first?
References
- Rose C. & Wright G.Nature, 431. 47 - 49 (2004). | Article | PubMed | ISI | ChemPort |
- Cocconi G. & Morrison P. Nature, 184. 844 - 846 (1959). | ISI |
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