Our Galactic Significance

As noted in Keith Windschuttle’s Chronicle (May 2012), Bob Brown received almost universal media derision for his speculations concerning the absence of contact with possible intra-galactic technological life-forms, and his support for “one-world democratic government”, somehow immune from takeover by some form of global autocracy. While Senator Brown’s thoughts concerning a global government seem in the “far out crazy” category, his comments regarding the “Great Silence” from some fifty years of searching (by SETI—“search for extra-terrestrial intelligence”— radio-astronomers) for some indication of another technology-based civilisation “out there”, are worthy of more serious consideration.

As the American radio-astronomer Frank Drake has pointed out, we can multiply together a sequence of estimated probabilities, none of which can be zero, to calculate the number of technology-based civilisations—at least one—among the Milky Way galaxy’s billions of stars, many (perhaps most) of…