To Explain the World: The Discovery of Modern Science by Steven Weinberg Page B

something about which neither Clarke nor Leibniz could have had any knowledge whatever.
    In the end the opposition to Newton’s theories didn’t matter, for Newtonian physics went from success to success. Halley fitted the observations of the comets observed in 1531, 1607, and 1682 to a single nearly parabolic elliptical orbit, showing that these were all recurring appearances of the same comet. Using Newton’s theory to take into account gravitational perturbations due to the masses of Jupiter and Saturn, the French mathematician Alexis-Claude Clairaut and his collaborators predicted in November 1758 that this comet would return to perihelion in mid-April 1759. The comet was observed on Christmas Day 1758, 15 years after Halley’s death, and reached perihelion on March 13, 1759. Newton’s theory was promoted in the mid-eighteenthcentury by the French translations of the Principia by Clairaut and by Émilie du Châtelet, and through the influence of du Châtelet’s lover Voltaire. It was another Frenchman, Jean d’Alembert, who in 1749 published the first correct and accurate calculation of the precession of the equinoxes, based on Newton’s ideas. Eventually Newtonianism triumphed everywhere.
    This was not because Newton’s theory satisfied a preexisting metaphysical criterion for a scientific theory. It didn’t. It did not answer the questions about purpose that were central in Aristotle’s physics. But it provided universal principles that allowed the successful calculation of a great deal that had previously seemed mysterious. In this way, it provided an irresistible model for what a physical theory should be, and could be.
    This is an example of a kind of Darwinian selection operating in the history of science. We get intense pleasure when something has been successfully explained, as when Newton explained Kepler’s laws of planetary motion along with much else. The scientific theories and methods that survive are those that provide such pleasure, whether or not they fit any preexisting model of how science ought to be done.
    The rejection of Newton’s theories by the followers of Descartes and Leibniz suggests a moral for the practice of science: it is never safe simply to reject a theory that has as many impressive successes in accounting for observation as Newton’s had. Successful theories may work for reasons not understood by their creators, and they always turn out to be approximations to more successful theories, but they are never simply mistakes.
    This moral was not always heeded in the twentieth century. The 1920s saw the advent of quantum mechanics, a radically new framework for physical theory. Instead of calculating the trajectories of a planet or a particle, one calculates the evolution of waves of probability, whose intensity at any position and time tells us the probability of finding the planet or particle then and there. The abandonment of determinism so appalled some of the founders of quantum mechanics, including Max Planck, Erwin Schrödinger, Louis de Broglie, and Albert Einstein, that theydid no further work on quantum mechanical theories, except to point out the unacceptable consequences of these theories. Some of the criticisms of quantum mechanics by Schrödinger and Einstein were troubling, and continue to worry us today, but by the end of the 1920s quantum mechanics had already been so successful in accounting for the properties of atoms, molecules, and photons that it had to be taken seriously. The rejection of quantum mechanical theories by these physicists meant that they were unable to participate in the great progress in the physics of solids, atomic nuclei, and elementary particles of the 1930s and 1940s.
    Like quantum mechanics, Newton’s theory of the solar system had provided what later came to be called a Standard Model. I introduced this term in 1971 21 to describe the theory of the structure and evolution of the expanding universe as it had developed up to that time,