Extraterrestrial life should be common. Discussing this with colleagues over lunch in 1950, physicist Enrico Fermi asked: "Where are they?" or "Where is everybody?" The paradox is between evidence for its likelihood, and lack of evidence for its existence
As just about every statistics student can attest, Simpson's Paradox — a statistical phenomenon where an apparent trend is reversed when you look at subgroups — is notoriously hard to explain. You can look at examples — say, the fact that US wages are rising overall, but dropping within every educational group — but that don't really help to explain the paradox. But it's not really paradox at all, but simply the fact that the disparate rate at which members of the study join the subgroups isn't accounted for in the analysis. To demonstrate this effect, the Visualizing Urban Data...
With billions of planets capable of supporting intelligent life, why no visits to earth? This is "The Fermi Paradox." Any civilization, with modest rocket tech & immodest funds, could rapidly colonize the Milky Way...
paradox that a high-fat, high–saturated fat diet is associated with diminished coronary artery disease progression in women with the metabolic syndrome, a condition that is epidemic in the United States. This paradox presents a challenge to differentiat
F. Kooti, N. Hodas, and K. Lerman. Proceedings of the eighth International AAAI Conference on Weblogs and Social Media, page 266--274. AAAI, AAAI Press, (June 2014)