Tenacity and stubbornness: Einstein on theory and experiment -- Convergence or coincidence: ancient measurements of the sun and moon, how far? -- The rationality of simplicity: Copernicus on planetary motion -- A silence of scientists: Venus's brightness, Earth's precession, and the nebula of Orion -- Progress through error: stars and quasars, how big, how far? -- The data fit the model but the model is wrong: Kepler and the structure of the cosmos -- Art illustrates science: Galileo, a blemished moon, and a parabola of blood -- Ensnared in circles: Galileo and the law of projectile motion -- Aesthetics and holism: Newton on light, color, and music -- Missing one’s own discovery: Newton and the first idea of an artificial satellite -- A change of mind: Newton and the comet(s?) of 1680 and 1681 -- A well-nigh discovery: Einstein and the expanding universe.