Alien Intelligence and the Drake Equation

I believe that we are not alone in the universe.

Mulder's Poster - "I Want To Believe"Before I say more, I assure you I’m not a crazy person. I’ve never been abducted, made the subject of experiments or contacted telepathically by little green men with large foreheads. I approach stories of cattle mutilation and crop circles with the same caution I apply to astrology, spontaneous human combustion, and organized religion. I’m a skeptic.

Like Fox Mulder, “I want to believe,” but tales of UFO encounters are fraught with fuzzy photographs and sketchy testimonials. Any sufficiently rigorous investigation of these anecdotal sightings or abductions only casts significant doubt on the veracity of the claims. Still, as beliefs go, contact with E.T. is near the “plausible” end of the spectrum, and I’m open to the possibility that my fiancée has been abducted and replaced by a pod person.

It’s just an extremely small possibility.

Late astrophysicist and science advocate Carl Sagan was fond of saying, “Extraordinary claims require extraordinary evidence.” This maxim is a general empirical rule that serves to deter fraudulent claims, and it applies to scientific professionals and members of the general public alike. The claim of first contact is certainly extraordinary and unprecedented, in fact, throughout recorded history.

Manufacturing a fantastic story of alien home invasion is easy, and there are various motivations to do so. Hoaxes are designed to attract media attention and notoriety, even profit in some circumstances, and conveniently avoid the responsibility of providing a story that might be duplicated or amenable to study. There are no detailed photographs of the innards of a spacecraft—no artifacts to prove abduction, visitation, or existence whatsoever.

The lack of evidence itself is suspicious and indicates a cultural undercurrent that has swept up a certain, excitable element into believing ideas that are improbable to the point of absurdity. This often fanatical subculture of conspiracy theorists, ghost hunters, and UFO chasers has sprouted in parts of the US and Great Britain in recent decades (although fear of alien invasion dates most dramatically back to Percival Lowell’s belief in Martian canals in the late 19th Century).  Peaking in the 1970s and ‘80s, this movement added momentum to the idea that alien civilizations dispatched emissaries through billions of light years and cold, brutal interstellar space to flatten wheat fields on Earth into geometric patterns.

Other allegations of alien contact may result from delusions, hallucinations, or drastic misunderstanding of events, such as the misinterpretation of meteor showers or artificial satellite re-entries as close encounters.

Regardless of social and psychological factors, UFO enthusiasts tend to overestimate the scope of the Earth’s presence in space. For example, radio waves have been propagating into space in every direction since the first taps on electric telegraphs in the 19th Century. The first radio transmission of significant power was made in 1901 by Guglielmo Marconi, a broadcast that marks the edge of the expanding bubble of Earth’s influence in the galaxy around it. Approximately 111 light years in every direction, humanity’s first radio broadcasts are arriving in interstellar space. “At [75] light-years away, television signals are being introduced. Star systems at a distance of [51] light-years are now entering The Twilight Zone.*

Conversely, the UFO faithful tend to underestimate the sheer, unimaginable size of the universe and the implications of so-called “deep time” for space travel. It’s tough to find fault with that; I’d argue the human brain just isn’t powerful enough to comprehend the endless enormity of our universe. Furthermore, the edge of the visible universe—the farthest objects we can see with our most sophisticated telescopes—is about 14 billion light years away. That’s only a fraction of the stuff that’s out there, since space expands from every point within itself.

It’s presently estimated the universe contains around 350 billion galaxies like our own Milky Way, cast across billions and billions of years: epochal, cosmic time for which we humans have no reference. These are realities utterly beyond the experience of our species. We represent merely the momentary flare-up of isolated intelligence in an otherwise indifferent ocean of time, space and darkness. Interstellar travel, given current technologies and theories, is generally untenable, although there is evidence that the Voyager 1 space probe became the first piece of mankind to exit our local solar system on October 4, 2012. Voyager was launched in 1977 and still sends data to NASA. The space agency says they’ll lose radio contact with the satellite around the year 2025 due to increasing radioactive interference.

The situation seems bleak for humanity. We were raised on a lovely garden planet at the edge of a quiet backwater galaxy. All science can tell us is how we came to be here, but the why is a slipperier issue.  All anyone knows for sure is we’re alone. If we’re to believe what our eyes and ears tell us, there’s nobody out there. This leads, for some, to the belief that we humans are special, somehow divine, to be singled out for existence on our beautiful world.

While I agree the Earth is beautiful, I’d rather not jump to conclusions about how we ended up here. Such assumptions are unbecoming of modern people who no longer need superstition to describe their world. For a more factual analysis, astronomer, physicist, and founding member of SETI (Search for Extra Terrestrial Intelligence) Frank Drake developed his Drake Equation as a tool to decipher just how special humanity might be in the vast universe we inhabit. It allows the E.T.-curious to calculate precise and reasonable estimates, and it provides insight into the potential for life elsewhere in the galaxy.

The Drake Equation looks like this:

Drake Equation

Here’s what it means:

N is the figure we’re calculating: how many other advanced species, like or unlike ourselves, might be searching their skies for us?

R is the rate at which stars like our own sun form in the Milky Way. This number is provided by astronomers who estimate that one solar- type star forms about every year. The size and brightness of the star are crucial factors to consider; excluding large, fast- burning goliaths and small, dim dwarf stars gives planetary systems the time necessary for complex evolution to occur.

fs is the fraction of solar-type stars that have planets.

ne is the fraction of habitable worlds per solar system. These planets must orbit within their star’s “Goldilocks zone.” Not too hot. Not too cold. Earthlike worlds’ orbits will need to be just right for the energy of their parent star.

fl is the fraction of Earthlike planets on which life actually occurs. Some otherwise Earthlike planets might have methane atmospheres like Saturn’s moon Titan, oceans of sulfuric acid, or a myriad of other conditions thought unsuitable for life.

fi is the fraction of Earthlike planets on which life arises and intelligent species evolve. This is a hotly debated figure since nobody can say for sure whether intelligence is an inevitable evolutionary state.

fc is the fraction of Earthlike planets that support life on which intelligent life arises and develops the technology to send messages into space, as we have. We hope they’re looking for us with the same sense of purpose that we feel.

L represents the estimated lifetime of an advanced, technological civilization. During the Cold War, this number was generally calculated to be very small indeed. Again, the issue here is deep time, which goes even beyond geologic timescales of hundreds of millions of years. Many civilizations may have come and gone in more than 13 billion years or have yet to evolve on alien worlds. It’s helpful to remember the age of our own civilization is measured in tens of thousands of years.

Several elements within the Drake Equation, such as the estimated life span of an alien civilization, are pure conjecture, but the equation was never intended for hard science. It was designed to encourage dialogue and introspection on the topics of alien life and humanity’s place in the cosmos. As a thought experiment, it inevitably leads to one of three big thoughts. Either we are truly alone, drifting disconsolately through the heavens. Or perhaps there’s a smattering of technical civilizations out there, but they’re so distant that contact (or even acknowledgement) is simply impossible given current technology and physics theories. The third big thought is that if criteria like evolutionary spontaneity and civilization lifetime are assigned more liberal figures (which may very well be accurate), N, or the number of advanced worlds, jumps significantly, meaning the galaxy may yet contain hundreds, thousands, or even millions of civilizations.Carl Sagan

Sagan’s own figures reflect his famous optimism. In Cosmos, he wrote, “With a third or half a trillion stars in our Milky Way alone, could ours be the only one accompanied by an inhabited planet? How much more likely it is that technical civilizations are a cosmic commonplace, that the Galaxy is pulsing and humming with advanced societies, and, therefore, that the nearest such culture is not so very far away—perhaps transmitting from antennas established on a planet of a naked-eye star just next door.”

Of course, there’s no hard evidence either way, but the application of deductive reasoning in considering the magnitude of the universe enables more thorough reflection about our time and place within it. Ignoring lack of proof is the very definition of belief.

Against my better nature, I choose to believe that humans evolved as a way for the universe to know itself, to investigate its origins, to unlock its deepest mysteries. I believe the rise of intelligence is hard-wired into the laws of nature. I believe there are (or have been) civilizations unimaginably more advanced than our own, spanning millions of years, that eventually yield to the demands of deep time.

I believe the universe is much larger than we assume during idle contemplation and our influence much smaller. However, if thousands of civilizations rise and fall in our galactic neighborhood within a given time frame, the prospect of first contact would suddenly seem plausible: an event that would fundamentally change the lives of all those spinning on this beautiful, extraordinary and miniscule world.

I believe we are not alone in the universe. Otherwise, it seems like a terrible waste of space.