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Cosmic Archaeology: Taking the Sting Out of the Drake Equation


Here’s a clever way of taking the sting out the Drake equation. Frank Drake’s work has previously been a stumbling block for materialist understandings of the cosmos. As Tom Bethell has explained (“The Anxious Search for Extraterrestrials“):

Frank Drake, a Cornell astronomer, took it upon himself to demonstrate that life arising by chance was highly probable. By 1959, scientists could listen for signals from aliens using radio telescopes and a listening post was set up in West Virginia. Drake cobbled together what became known as the Drake Equation. It estimates the probability that intelligent beings are out there somewhere.

You take the number of stars and multiply by the fraction that have planets, times the number of planets per star, times the fraction within a habitable zone, times the likelihood of life evolving, times the probability of it reaching a level where critters can build radio transmitters — and so on.

But as Michael Crichton pointed out there was no data to work with. So enthusiasts were free to plug in their own numbers. That’s how Sagan came up with his “one million” civilizations. “Physics and chemistry are so constructed as to make the origin of life easy,” he assured us.

If our habitable planet is common currency and life evolves so easily, with intelligent life and civilization following readily in its wake, then why do we record no evidence of such life out there — no contact from ETs, not a peep? Could it be that life is so unlikely as to require a designer’s guidance for it to come into existence? Hence the anxiety.

Ah, but you see, it’s because all the previous alien civilizations have gone extinct! Just as — so fashionable opinion never tires of telling us — our own threatens to do.

Reporting in the journal Astrobiology (“A New Empirical Constraint on the Prevalence of Technological Species in the Universe“), Adam Frank at University of Rochester and Woodruff Sullivan at the University of Washington gave the matter a rethink, and played with the variables.

“Rather than asking how many civilizations may exist now, we ask ‘Are we the only technological species that has ever arisen?” said Sullivan. “This shifted focus eliminates the uncertainty of the civilization lifetime question and allows us to address what we call the ‘cosmic archaeological question’ — how often in the history of the universe has life evolved to an advanced state?”

Whether Earth’s intelligent life has or had parallels elsewhere all depends on how readily previously dead matter evolves such an astonishing pattern. If it does so relatively easily, then many other inhabited planets like Earth have probably gone before us:

Are humans unique and alone in the vast universe? This question — summed up in the famous Drake equation — has for a half-century been one of the most intractable and uncertain in science.

But a new paper shows that the recent discoveries of exoplanets combined with a broader approach to the question makes it possible to assign a new empirically valid probability to whether any other advanced technological civilizations have ever existed.

And it shows that unless the odds of advanced life evolving on a habitable planet are astonishingly low, then human kind is not the universe’s first technological, or advanced, civilization.

The news item from the University of Rochester includes an opportunity to plug in your own variables and see the results. If you select the Milky Way as your area of interest and then a likelihood of evolving intelligent life at 1 in 10,000 (10^-4), then the result is some 6 million civilizations, past or present. If you choose 10^-24, then “We are the first advanced civilization.” There are, and have been, no others.

Why the uncertainty? “We didn’t know how many of those stars had planets that could potentially harbor life, how often life might evolve and lead to intelligent beings, and how long any civilizations might last before becoming extinct,” Dr. Frank is quoted as admitting. That’s a lot not to know.

On the other hand, we do know that evolving a civilization involves hurdles downstream from a far more basic problem — getting a functional protein. No building blocks of life means, inescapably, no life. ETs don’t need to be designed precisely as we are for this to be true. Biologist Ann Gauger puts it simply:

Research indicates that sequences that fold into a particular functional shape are rare. Only about 1 in 10^77 possible sequences will adopt a functional fold 150 amino acids in length.

Proteins exhibit exquisite design, with extraordinary specified complexity embedded in their sequences. Too much to be the result of random processes.

This is the issue on which Richard Dawkins’s recent dispute with Stephen Meyer turned (“Dawkins’s Dilemma: Misrepresent the Mechanism…or Face the Math“). To speak of intelligent life developing, putting odds on that, seems beyond calculation.

But reckoning on civilizations having extinguished themselves is an ingenious move and grants evolutionists a tenuous handhold. How can anyone prove there aren’t scads of dead Earths out there? It also fits well with the ethos of the moment, an apocalyptic one that sees civilization and technology’s advance, human flourishing itself, as an exercise in self-destruction.

Image: A new and improved Drake equation, via University of Rochester.

David Klinghoffer

Senior Fellow and Editor, Evolution News
David Klinghoffer is a Senior Fellow at Discovery Institute and the editor of Evolution News & Science Today, the daily voice of Discovery Institute’s Center for Science & Culture, reporting on intelligent design, evolution, and the intersection of science and culture. Klinghoffer is also the author of six books, a former senior editor and literary editor at National Review magazine, and has written for the Los Angeles Times, New York Times, Wall Street Journal, Washington Post, Seattle Times, Commentary, and other publications. Born in Santa Monica, California, he graduated from Brown University in 1987 with an A.B. magna cum laude in comparative literature and religious studies. David lives near Seattle, Washington, with his wife and children.