Ask Dr. SETI ®
by David Brin
Anyone who ever watched the film CONTACT knows about SETI, listening for signs of other civilizations, sifting for that needle in the Cosmic Haystack. For decades, this inexpensive and scientifically valid Search for Extra-Terrestrial Intelligence has risen in public esteem. Consider how quickly we’re learning about the cosmos; twenty years ago, humanity knew of no planets, outside our solar system. Now we've catalogued thousands. It only seems sensible to peer about for signs of sapience, out there. No matter whether you're an optimist about First Contact or a pessimist - and whatever you deem to be the odds - it never hurts to improve our situational awareness, right?
So, how's that search for aliens going? I've been involved, both as an astronomer and an author of science fiction novels, for forty years. And so far, our best searches haven’t uncovered a peep.
This null result does not prove no one’s out there! Space is big! But it does have a lot of us poking at the famous Drake Equation and what has come to be called the “Fermi Paradox,” pondering why advanced and detectable civilization does seem to be… well… at least a bit sparse in our local neighborhood. And this may be why some SETI-ists have declared a new ambition - to poke at the experiment by sending out beams, rather than just listening. Shouting into the cosmos.
METI - Messaging to ETI, (also known as Active SETI) - is controversial. Proponents seek to transform one of Earth's basic traits, its radio profile, without submitting their plan for peer criticism or environmental impact study. Many of us want to delay changing a major, observable trait of Earth, long enough to first hold wide-ranging discussions, including our finest sages and the public. Because all of the excuses offered by METI-zealots turn out to be flat-out wrong.
Take their centerpiece - the so-called “barn door” assertion: that it is useless to delay sky-beaming projects, because that would be like trying to close a stable, after the horses already bolted. In other words, military radars and big TV broadcasts, especially during the our planet's noisiest decade - the 1980s - were already loud enough for ET to know there's a technological race fussing around, down here. After so many Hollywood films, any member of the public might assume we’re heard everywhere! In fact, even the METI guys admit that 1980s Earthnoise faded into background within half a light year --
-- unless a super advanced race out there aimed truly humungous space-dishes the size of Connecticut our way, pointing at a trillionth of a trillionth of the sky, for dwell times up to a year -- necessary because TV and radar are non-coherent, dopplered by Earth’s rotation, and muddled by many overlapping transmitters. Sure, such super-duper alien dishes might be built in vast numbers. (I even portray this, in my novel Existence.) Or maybe not. The key point is that there is no “of course” to the Barn Door assertion. It is not a given that aliens automatically already know we’re here.
Mind you, there are a few transmitters on Earth that could be detected at interstellar ranges, not from leakage" but deliberate, narrow, coherent and concentrated beams. Arecibo is one of these and there are perhaps five more called Planetary Radars. Try signaling to someone on a far-off boat with a match, then with a large laser-pointer. That’s roughly the difference between these planetary radars and the ones at your typical airport.
The real answer to the Barn Door Excuse is simple. METI zealots aim to draw attention to our world, by aiming laserlike beams that multiply Earth’s at-target visibility many millions-fold. They aim to achieve an effect! Which means that they do not believe that ET already knows about us, after all.
There is another talking point raised by these fellows -- that moratoria and pre-discussions do not work. They dismiss the "Precautionary Principle, that even low probability outcomes should be examined, if their potential for harm might be great. Above all, they assert that it is pointless to worry about potential risks that have no known example.
That assertion is decisively disproved by counter-example. For example, NASA maintains a vigorous Planetary Protection Office, tasked with reducing potential harm in missions to other worlds. Probes that will land on another body, such as Mars, are given extra cleaning and sterilization, to minimize the possibility that Earthly microbes might be released onto the red planet. These efforts are redoubled when samples get returned home to Earth. These measures are not expected to be perfect, nor ever to thwart exploration. And there are many other such endeavors. Our civilization has already decided - in principle and in practice - that moderate expense for reduction of risk is worthwhile, even with regard to a "danger" that has no known example. Especially when precautions do not obstruct (over the long run) mature science.
Nor would any moratorium on transmission be permanent. How could it be? Here on Earth, given rapid advances of technology and a rambunctiously individualistic civilization, the capability to transmit laser-like signals that might be detectable across many light years will be in private hands, within a decade or two. Permanent "muzzling" was never proposed and is quite infeasible. Nevertheless, a world discussion before that day arrives can have only positive effects.
The point here is that it is possible for reasonable people to get past their "of course" assertions in the course of collegial processes that are proved to have addressed "low-probability but high-impact" concerns.
In the 1980s, members of the SETI community developed a Declaration of Principles (better known as the first SETI Protocols) that established procedures for handling the detection of an alien signal or other evidence of an extraterrestrial civilization. The basic principles are three: confirm the detection; announce a confirmed detection to the world; do not send a message to the detected intelligence until an international process of consultation has taken place. The Second Protocol - in its original, widely accepted form - called for such extensive consultation before de novo calls into the cosmos (not responding to a detection.) That was the whole and entire purpose of the Second Protocol.
While the Protocols were never formally adopted by any governments or international bodies, they achieved the only slightly-lower potency of a "declaration of best practices" that was accepted by consensus by almost everyone in the astronomical community who had appreciable involvement in SETI. Unfortunately, a very small group of METI enthusiasts have declared the Second Protocol to be moot.
To be clear, those of us who want pre-discussions, before METI do not object to theoretical studies, for example drafting and critiquing detailed messages could leave us better prepared for certain contact scenarios. Indeed, several of us METI-dissenters openly participate in such activities, such as the endeavor to upload "messages" onto the New Horizons spacecraft, after it races past Pluto. Indeed, the value in attracting interest from the worldwide public - especially world-youth -- is appreciated. Indeed, the “pre-discussions” we seek could be televised, involve the world’s most fascinating sages, and draw tens of millions of avid participants from the general public. In fact, we remain confused as to why the zealots wouldn’t want that.
These are the sorts of activities we should be pursuing, instead of slinging un-vetted and potentially dangerous screams for attention into space, arrogating a never-earned right to speak for all of humanity.
Is there anything that can be tested, right away, in SETI and in METI? I contend that there is one experiment we can do swiftly and cheaply. Take a few dozen semi-randomly chosen, modern and college educated citizens without previous bias and poll them about METI without much background prep. Just maybe 5 minutes each from proponents and opponents to transmissions from Earth, followed by a simple straw vote on Active SETI. From experience, I deem it almost certain a majority will side - initially - with the METI guys.
But then, in phase two, expose that panel to a few hours of extensive tutorials about SETI, about the ‘cosmic haystack' and the Fermi Paradox and the scale factors of the Barn Door Excuse… and I bet this will reverse. A majority will urge extended moratorium with large scale and eclectic-scientific pre-discussions - in front of a world audience - before sky-beamings should commence. Preliminary straw polls at both the Royal society and AAAS went exactly this way.
That is my challenge. A testable hypothesis. A simple test of which direction intelligent citizens sway, in proportion to how much more they learn about this topic - one of the most fascinating ever to land before our educated and science-fascinated public.
For further discussion, see:
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this page last updated 4 April 2015
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