Most of us know about all we need to know about Galileo Galilei - a great early scientist whose telescopic observations of the phases of Venus and Jupiter's moons pretty much put paid to Ptolemy's ancient system in which all heavenly bodies circled the Earth. A martyr (of sorts) who was tried by the Catholic Church for advocating Copernicus's heliocentric system and forced to recant. A guy who, according what probably is a mere legend, muttered - kneeling before the Inquisition - "And yet it moves" (referring to the Earth).
But you want to know about the middle finger. Professor Alex Filippenko, the teacher of a lecture series I'm watching, said Galileo is one of his heroes, and after his senior year in college he traveled to Europe, visited Florence, and stumbled on a relatively small museum of science called the "Istituto e Museo di Storis della Scenzas" - the "Florence Institute and Museum of the History of Science" to you. Wandering through the collection of medieval scientific instruments, Filippenko came across the phalange in question.
It stands upright within a small glass egg, held in a larger cup, looking for all the world like, well, the finger.
Most sources I checked on the Web - secondary sources that were very secondary - said that after Galileo's death students stole the middle finger of his right hand from the corpse. Another source implied the whole hand was taken, and the finger wasn't snapped off until 95 years later (when it had sufficiently aged). Then it was "passed around" for a few hundred years until the Florence museum obtained it. Not the most exacting of provenance.
Anyway, as one Web site said, "It stands displayed upward defying all those that opposed the advances of science." Or maybe it remains little more than a student prank. I'll let you decide, if decide you must.