gnostek1 / 16Enrico Fermi (Los Alamos 1945)
- 01Fermi posed the question over lunch at Los Alamos in 1950; his colleagues remembered it for decades.
- 02The Milky Way is old enough for a civilization to have colonized every star system 1,000 times over.
- 03Michael Hart's 1975 paper was the first formal treatment; the silence still has no consensus explanation.