"Intuitively, Planck knew that his work was as important as Newton's in paving a new physics, as he privately confided to his son in 1901. Because of his own conservative beliefs, Planck felt stymied by the revolutionary nature of his own ideas... In truth, Planck was only underestimating the importance of his work, if anything. In retrospect... it started a revolution in science—the quantum revolution—compared to which the Copernican revolution pales."