On June 22, 1633, Galileo was sentenced by the Roman Inquisition for being "vehemently suspect of heresy." He had told the truth, that the earth revolved around the sun according to astronomical evidence, but he was forced to recant that truth. There is a great deal of scientific knowledge we either would not have today, or would have obtained in very different ways, if Galileo had chosen a different course, if he had been "silenced" by more violent means. Speaking truth to power, as the saying goes, is rarely as clear as it sounds. Sometimes it doesn't require formal speech at all. A simple smartphone video can have the same impact today.