Nick Bostrom at Oxford’s Future of Humanity Institute takes on Fermi’s question “Where are they?” in a new paper on the possibility of life on other planets. The paper posits probability filters (Great Filters) that may have existed in the past or might be still to come and that limit the likelihood of the outcome that we currently observe: our own, ahem, intelligent life. If a Great Filter existed in our past—say the event of abiogenesis or prokaryote to eukaryote transition—then we can somewhat explain the lack of alien contact thus far: our existence is of very low probability. Moreover, we can expect to not find life on Mars.

If, however, the Great Filter exists in our future then we might see life all over the place (including the theme of his paper, Mars). Primitive life is abundant but the Great Filter is somewhere in our future where we annihilate ourselves, thus explaining why Fermi’s They are not here while little strange things thrive on Mars, and beyond. It is only advanced life that got squeezed out by the Filter.

Bostrom’s Simulation Hypothesis provides a potential way out of this largely pessimistic perspective. If there is a very high probability that civilizations achieve sufficient simulation capabilities that they can create artificial universes prior to conquering the vast interstellar voids needed to move around and signal with adequate intensity, it is equally possible that their “exit strategy” is a benign incorporation into artificial realities that prevents corporeal destruction by other means. It seems unlikely that every advanced civilization would “give up” physical being under these circumstances (in Teleology there are hold-outs from the singularity though they eventually die out), which would mean that there might remain a sparse subset of active alien contact possibilities.… Read the rest