Copyright 1990 Don Benish


By Don Benish


A large number of distinguished astronomers have come forward in recent years proclaiming that the universe is filled with intelligent life beyond our own planet. Even limiting their speculations to our own galaxy, estimates by believers range from several tens of such species to several millions, all trying to communicate with us. Science fiction writers have long used a multitude of alien species to build their stories around. Now such fiction is being promulgated as fact.

The fervor of some such advocates approaches religious intensity. Their beliefs that there just MUST be such beings out there, waiting for us to discover them, leads them to embrace downright illogical statements and gigantic leaps of faith. Their pseudo-science has abandoned the logical, verifiable precepts of true science in the search for a 'holy grail'. They use their arguments to plead for additional funds to pursue such research. But in my mind what is worse they dilute the cause of true science. Their arguments are taken by an innocent trusting populous as absolutely true. It is very tempting to speculate on the existence of an all-powerful race of superbeings who will come here and rescue us from our petty traumas. In this day of big brother government, the search is on for an even bigger brother.

Rather, I say we should grow up and accept the responsibility of our own salvation. We are not likely to encounter another alien intelligence in the forseeable future. We should admit to ourself that we are alone and must get up off our butts and take the universe for our own.

The basic argument that the advocate uses to press his point is in the form of an equation concieved by astronomer, Frank Drake. His equation takes the product of a number of probability terms to finally determine the probable number of communicating, technic societies in the Milky Way Galaxy. The equation is expressed by the following:



    N is the total number of communicating societies.
    A is the total number of stars or starlike masses in the galaxy.
    B is the fraction of stars that have a planetary system.
    C is the fraction of planetary systems that have at least one planet capable of initiating and sustaining life.
    D is the fraction of planets wherein life actually is initiated and is sustained.
    E is the fraction of those planets on which an intelligent lifeform eventually evolves.
    F is the fraction of those intelligent lifeforms that develop a technic society such that they are detectable by interstellar observers.
    G is the fraction of a star's entire lifetime wherein the technic society is maintained.

Many advocates have attempted to solve the equation, but they invariable exaggerate the probability of portions of the equation that lie beyond their personal domain. Questions of biology and the rise of intelligence are generally mishandled by persons whose area of expertise is astronomy or physics. Further, assumptions on probabilities that are not well understood, are are generally not well analyzed and tend to be far too optimistic to be reasonable.

So, here is my contribution to the ongoing debate. I have made my own judgements of what I feel are the most reasonable values to assign to the various elements. I have attempted to explain my judgements and where I derived the values assigned to the various elements. My greatest hope is for someone to decide I am full of bullshit and publish his own more rigorous and technically accurate analysis.