FELLOW Earthians,

Never before has the universe unfolded such a flower as our collective human intelligence, so far as we know. Nor has such a one-and-only brilliance in the universe stood at the brink of extinction, so far as we know.

We people of the Earth exist because our potential was there in the Big Bang, 13.7 billion years ago, as the universe exploded into being. So far, it seems like we are the lone thinkers in this vast, expanding universe. However, recent astronomy tells us that there are trillions of other planets circling sun-like stars in the immensity of the universe, millions of them friendly to life. So why has no one from elsewhere in the cosmos contacted us?

Surely some people-like animals have evolved elsewhere. Surely we are not, in this crowded reality of countless other similar planets, the only thinking beings to have turned up. So why isn't life out there contacting us? Why aren't the intergalactic phones ringing?

Here is one sobering possibility for our isolation: maybe life has often evolved to intelligence on other planets with biospheres and every time that intelligence, when it became able to alter its environment, did so with catastrophic consequences. Maybe we have had many predecessors in the Cosmos but all have brought about their own downfall.