Submission + - Why Life on Mars May Foretell Our Doom 3
Hugh Pickens writes: "Nick Bostrom has a long article that is well worth reading with an interesting interpretation why on the failure of the Search for Extra-Terrestrial Intelligence (SETI) for the past half a century is good news and why the discovery of life on Mars could foretell our doom. Bostrom postulates a "Great Filter," which can be thought of as a probability barrier and consists of one or more evolutionary transitions or steps that must be traversed at great odds in order for an Earth-like planet to produce a civilization capable of exploring distant solar systems. The Great Filter must be sufficiently powerful that even with many billions of rolls of the dice, one ends up with nothing: no aliens, no spacecraft, no signals. If the filter is in our past, there must be some extremely improbable step in the sequence of events whereby an Earth-like planet gives rise to an intelligent species and it follows that we are most likely the only technologically advanced civilization in our galaxy. But if the Great Filter is still ahead of us, that would mean that some great improbability prevents almost all civilizations at our current stage of technological development from progressing to the point where they engage in large-scale space colonization — perhaps some very powerful weapons technology that causes its extinction. If we discover life-forms on Mars, the effect would be to shift the probability against the hypothesis that the Great Filter is behind us. If Mars is found to be barren, we would have some grounds for hope that all or most of the Great Filter is in our past and in that case, we may have a significant chance of one day growing into something greater than we are now."
