BY: TED BARNABY
Accelerating space technology and our present understanding of the universe make it increasingly difficult for people to deny the existence of extraterrestrial life. Whether alien contact has actually been made is a completely different can of worms (and statistically unlikely); however, based on the ingenious equation of astronomer and Cornell professor Frank Drake, we can at least deduce that the existence of intelligent alien life is pretty well undeniable.
Drake drew up this famous equation in 1961, which would help calculate the probability of intelligent alien life in the universe.
N = Number of intelligent communicative civilizations.
R = Average rate of star formation (derived from our galaxy, the Milky Way).
f(p) = The fraction of these stars with planetary systems.
n(e) = The number of Earth-like planets per system.
f(l) = The fraction of those Earth-like planets with the capacity to develop life.
f(i) = The fraction of these life-supporting planets where intelligence forms.
f(c) = The fraction of these intelligent life-supporting planets which foster electromagnetic communications technology.
L = The life span of these intelligent communicative civilizations.
In layman’s terms this complicated equation calculates the statistical likelihood of extraterrestrial life by multiplying out all relative probabilities (which are listed above). What’s interesting about the equation is that it indicates that alien life is statistically inevitable (even if not in our galaxy, but rather the universe as a whole.)
According to BBC’s Drake Equation calculator, even if you were to plug in the lowest possible values for each component of the equation, although sadly there would be no communicating civilizations in our galaxy, there would still be about 15,000 in the universe at large. Using the same calculator, if you punch in “today’s skeptical estimate”—using the most conservative scientific data available—the number of communicative civilizations in our galaxy jumps to one, and in the universe, an incredible 78 billion. However, according to Drake’s own estimates, there exist 10,000 communicative civilizations in our galaxy alone.
The SETI (Search for Extraterrestrial Intelligence) League contends that the value of the equation is not in solving it, but rather in its contemplation. It gives structure to the search for extraterrestrial life, and at least illustrates the immense probability of alien life in our galaxy, and beyond.
Furthermore, perhaps it’s worth noting that the average distance between these theoretical civilizations has been estimated to be at least two hundred light-years. What this means, as Bill Bryson puts it in “A Brief History of Nearly Everything,” “…even if these beings know we are here and are somehow able to see us in their telescopes, they’re watching light that left Earth two hundred years ago. So they’re not seeing you and me. They’re watching the French Revolution and Thomas Jefferson and people in silk stockings and powdered wigs…”
With this in mind, the Drake Equation tells us two very interesting and important things:
Firstly, that intelligent alien life is out there.
Secondly—and more sombrely—that for all practical purposes, we are alone.