Several possibilities:
1) Earth is the ONLY place in the entire cosmos where intelligent, self-aware life has come to be.
2) Intelligent life — and presumably civilizations — are numbered as the uncountable grains of sand on all the beaches, and far, far more.
3) If (2), and assuming fairly random evolving times, after the second and third generation stars came into being, fused the heavier elements into being as they exploded and then spilled their guts out for the forth generation of stars to form from the dust and gas, and see life and civilizations come to be on their orbiting worlds — this entire process takes millions and billions of years. This means if life is truly common and widespread, then the raw probability of many civilizations arising millions — if not billions of years BEFORE ours did — is quite high.
4) Why don’t we hear them “on the air” with our most sensitive and sophisticated radio telescopes? Easy one. They are way beyond anything as crude as “radio,” and are as detectable by us as our communications are detectable by ants.
5) It’s simply easier to believe “they” ARE “out there,” as not.
6) Even so, SOMEbody had to be first. Maybe it IS us...
All way beyond my pay grade...
Smell the flowers while there is Time...
Came here for the 2001 reference, goes away happy.
Exactly.