Church celebrates Galileo anniversary
DOI: 10.1063/PT.5.023916
Owen J. Gingerich , emeritus professor of astronomy and of history of science at Harvard University, swiftly ruled out the most famous and seemingly irrefutable accusation: that Galileo was tortured by the Church. The minutes of the interrogation, now preserved in the Vatican Archives, state that Galileo was to be “interrogated for vehement expression of heresy” and that included “legally being shown the instruments of torture."In an e-mail to Physics Today, Gingerich expands on some aspects of his lecture. “In this International Year of Astronomy we read that with his telescope Galileo proved the Copernican system (that the Earth goes round the Sun),” he says. But Galileo proved no such thing, he adds.
“Galileo would dearly have loved to find an irrefutable proof of the motion of the earth, but instead all he could do was to make the motion of the earth more reasonable and to assure readers that the Copernican system was a coherent way to look at the world.”
“What Galileo’s Dialogo did was make the motion of the earth intellectually respectable, and not just a ridiculous idea as the vast majority of people believed at that time. When I present this interpretation, I am typically asked, “In that case, when was the aha! moment when the Copernican system was finally proved?”
“In astronomy textbooks the Foucault pendulum and the annual parallax ofnearby stars are typically presented as proof for the motion of the earth. But those demonstrations came much too late, and by that time nearly everyone was already convinced by the Copernican cosmology.”
“What happened was that a persuasive new theoretical structure had emerged— Newtonian physics described in Isaac Newton’s Philosophiæ Naturalis Principia Mathematica —and the Principia was credentialed by a series of observations including Pierre Louis Maupertuis ‘s demonstrations of the oblateness of the earth , the predicted return of Halley’s comet , and James Bradley ‘s discovery of the aberration of starlight . So I am notdismissing observations, which are critical in providing persuasion. Butspecific proofs were not what suddenly produced the acceptance of theCopernican cosmology.”
Gingerich said that the Galileo controversy “essentially changed the way we do science because today science works primarily by persuasion and not by proof, and Galileo influenced how that happened.”
