The lost tomb of Caligula has been found, according to Italian police, after the arrest of a man trying to smuggle abroad a statue of the notorious Roman emperor recovered from the site.
To be able to compare scientists to one another, it is helpful to have a standard unit of fame. I proposed one that would make this kind of fame easy to comprehend: the Darwin. It is defined as the average annual frequency that "Charles Darwin" appears in English-language books from the year when he was 30 years old (1839) until 2000. Because it is such a big unit of fame, it has proved more convenient to use one-thousandth of that frequency: the milli-Darwin, abbreviated as mD.
This should not be confused with the "Darwin," a unit of evolutionary change. That unit—abbreviated with a small 'd'—was introduced by J.B.S. Haldane in 1949. But this duality serves only to illustrate the very nature of the measurement: Charles Darwin is so famous that he is the only scientist to have more than one unit named after him.