O paradoxo de Fermi revisitado [Com esta são 2000 as notas publicadas neste blogue]

The Allen Telescope Array in California. 

Photograph: Ho New/ Reuters 

Uma boa síntese da questão, e da história das tentativas de detecção dos nossos primos distantes [mais neste blogue, via motor de busca, sob "Fermi", "extraterrestres"; via etiqueta "ET"].

"It will soon be half a century since the American astronomer Frank Drake first pointed a radio telescope at the star Tau Ceti in the hope of picking up an extraterrestrial broadcast, and we still haven't heard anything. So is there anyone out there?" 

First contact: will we ever hear from aliens? | Feature | Culture | The Observer