Most sci-fi readers and writers are familiar with the Fermi paradox, summarized by the question in the title, and the associated Drake equation that tried to resolve it. For those who are not, let me review that history first before going on to discuss a different take on the Drake equation that I found interesting.
The Fermi paradox first appears in my sci-fi books in the second book of the “Chaos Chronicles Trilogy.” In Sing a Samba Galactica, Earth colonists on New Haven, an E-type planet in the 82 Eridani system, have evidence for some local ETs and try to figure out how to communicate with them. Here’s the excerpt:
They had an informal meeting in the bachelors’ dining area. Takahashi watched as Malenkov, ever the showman, pinged his beer mug with a laser pointer and then stood on top of a chair.
“At Los Alamos, in 1950,” he began, in his best orator’s voice, “the great Italian physicist Enrico Fermi asked Emil Konopinski, Edward Teller, and Herbert York, as well as other physicists working on the atomic bomb project, this provocative question: If life is so common in the universe, where are they?”
Malenkov waited for some chuckles to subside, gulped some beer, and continued.
“Fermi noted there are plenty of stars older than our sun. If life were so plentiful, it would have begun on planets around these stars billions of years before it began on Earth. In that case, shouldn’t Earth have been visited or colonized by a race much older than our own? Even with slow means of space travel like what we used to come to New Haven, a civilization with a will to homestead could settle a large fraction of the galaxy in a million years or so.”
Malenkov looked out at his audience. Takahashi, sitting in the cafeteria’s front row, smiled at him. So which one of us is Holmes and which one Watson?