(http://arXiv.org/abs/astro-ph/0108180)
D.S.L. Soares
Departamento de Física, ICEx, UFMG
-- C.P. 702
30161-970, Belo Horizonte -- Brazil
August 1, 2001
Time is on my side
The Rolling Stones, 1964
Every day in every way it's getting better and better
John Lennon, 1980
The affirmative statement of the existence of extraterrestrial life is tentatively raised to the status of a principle. Accordingly, Fermi's question is answered and the anthropic principle is shown to be falsifiable. The time-scale for the development of life on Earth and the age of the universe are the fundamental quantities upon which the arguments are framed.