R.A. Rajotte
The Fermi paradox ponders why we have so little evidence of intelligent alien life despite the overwhelming probability that alien life does exist. Named after Italian-American physicist Enrico Fermi it highights the apparent contradiction between the lack of evidence for and various estimates of a high probability of extraterrestrial civilizations within our galaxy, most notably the Drake equation.
Research associate from Future of Humanity Institute at Oxford University and professor at George Mason University Robin Hanson, attempted to resolve the Fermi paradox with the Great Filter hypothesis. [ The Great Filter - Are We Almost Past It? - R. Hanson ]. Hansons theory suggests something is wrong with one or more of the arguments from various scientific disciplines.
Hanson theorizes that there could be something standing in the path of life forms that prevents them from becoming interstellar. If a civilization achieves interstellar communication, that would mean we woulda coulda and shoulda made contact with them by now. But we haven't, not that Big Brother is letting us pee-ons know about anyway.
Assuming we haven't secretively made contact, Hansons theoretical roadblock, the "Great Filter" may be why.
The Great Filter hypothesis suggests that without something getting in the way, hospitable and habitable worlds should give rise to life. A goodly portion of that life should eventually evolve into tool-using large brained animals that eventually fan out beyond the home planet.
We humans are just beginning to venture beyond Mother Earths warm embrace, but we should of come across intelligent alien life, or rather they should have come across us - assuming they are at a more evolved state. And nothing has been detected, so either we're the only species to make it past this theoretical great filter or this filter has not yet weeded us out.
So what is this "Great filter" and have we already traversed it or is it still in our future ?
If we've gone past this theoretical filter, perhaps other life forms within interstellar reach haven't. Evolution from microbial life to simple multi-cell life forms is extremely rare, scientists claim [although none were there to witness it]. Perhaps more complex life forms are statistically obliterated by natural forces - meteors, asteroids or hemorrhoid's. Either happenstance would satisfy the Fermi paradox. Or perhaps there are multiple barriers and we have many more to traverse.
The Great Filter hypothesis is basically intergalactic Darwinism, survival of the fittest on a universal scale. Only the best, brightest and most fit civilizations make it past the filter and into this exclusive club.
When and if we discover life beyond Earth, perhaps we'll get a better grasp of where the filter or filters may be. We have found proof of simple life in our own solar system, if we found multicellular life within our solar system that would mean forming complex life is not as difficult as some believe.
Looking beyond the Great Filter hypothesis for an explanation as to why we haven't made contact with alien intelligence [that has been acknowledged anyway] perhaps the "Rodenberry Equation" should be considered - Star Trek fans buckle up - what's the Prime Directive ?
