Mercury,
September/October 2002 Table of Contents
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Courtesy
of Seth Shostak.
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by
Seth Shostak
Ben
Zuckerman is wrong. There are plenty of reasons why Earth hasn’t
been visited by extraterrestrials.
Is
there intelligence elsewhere in the Galaxy? Are there other beings
who not only can see the stars, but who can also understand where
they are and how they work? That’s the question today’s SETI experiments
try to address. A single signal from the cosmos — a sudden burst
of photons or a soft radio squeal — would immediately provide an
answer.
It
is now four decades since the first modern SETI experiment, and
we still have not detected and confirmed such a signal. This is
reason for some astronomers, including my distinguished opponent
Ben Zuckerman, to question the premises of SETI, or simply the likelihood
that it will ever succeed. To my mind, this is as if the crew aboard
The Resolution, Captain James Cook’s ship — having sailed for months
in search of Terra Australis Incognita — opted to set up debating
clubs to argue the possibility that they would ever stumble across
the postulated southern continent. In fact, debate would have been
far less useful than continuing to sail. Cook’s repeated probes
into uncharted southern latitudes both constrained the search space
and indirectly told his successors where to look next. In 1820,
nearly a half century after Cook’s forays, Thaddeus von Bellinghausen
finally sighted Antarctica. In other words, experiment is better
than debate, and that’s why SETI researchers continue to deploy
their telescopes.
Frankly,
it’s possible that tomorrow, next week, or next year, SETI will
receive a signal that renders all argument about the likelihood
of success obsolete and quaint. I personally believe that the telescopes
and techniques currently being developed — instruments that will
increase by three orders of magnitude the number of star systems
scrutinized for cosmic company – are likely to result in the detection
of someone else’s technology. But that’s my opinion. Meanwhile —
and in the spirit of interesting pugilistic polemics — I will take
issue with some of the rationale Ben Zuckerman has offered in support
of his assertion that SETI will fail. After all, he’s not only telling
us it will fail, he’s telling us why.
Click
here to read Ben Zuckerman's
response.
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