What was he thinking during the night of June 21-22, 1633, confined by the Holy Office in Rome, waiting for the moment the next day when he would be asked to kneel before the assembled cardinals and Dominican friars of the Inquisition and recite the recantation that had been prepared for him, denying that he now believed or ever had believed that the Sun, rather than the Earth, is the center of the cosmos? Seventy years old, blind, caught in a bind partly of his own making, believing firmly (we must suppose) that Copernicus' heliocentric system is true, but fearing too the fate that might await him should he refuse to recant. The Holy Office was not known for its gentleness with heretics.
The long hours of darkness. Thinking, perhaps, of his life's work, especially his spectacular telescopic discoveries, all of which led him inexorably to believe in the double motion of the Earth. Thinking too of the work he had yet to do, which would (as it turned out), even in his blindness, lay the foundations for modern physics. Thinking of his daughter, Sister Maria Celeste, who urged him to be a faithful son of the Church.
His body old, his sight gone. His pride intact. Now, surely, was the time to make a stand, to assert the evidence of the senses over blind dogma, stale authority. To resist the abject humiliation of kneeling on the cold marble floor, of speaking the objectionable words.
The hours. The minutes. The interminable darkness. Did he sleep? Did he imagine the flames licking at his feet should he fail to recant? Did he believe, even in some deep recess of his spirit, in the greater fires of Hell? Did he wonder about his immortal soul?