Pierre Curie was her husband but also her close collaborator, Joliot-Curie her daughter, and Joliot her son-in-law. Perrin was her next-door neighbour, close friend and professional colleague. Becquerel supervised her doctorate, and shared the Nobel Prize: Brillouin and Lippmann also taught her; she worked afterwards in Lippmann’s research lab. Langevin is popularly supposed to have had an affair with her; Borel and Poincaré (who also taught her) helped defend her. Valéry sat on a committee she chaired, Einstein was a long-term friend, Rutherford had been keen to meet her, and Rodin was visited in his studio.
Although Celsius is best known for the temperature scale bearing his name, he was primarily an astronomer. Having visited the main centres of astronomy in Europe, meeting Cassini among others, he was instrumental in the expedition led by Maupertuis going to Swedish (now Finnish) Lapland rather than to Norway; Clairaut was a companion on this difficult journey to establish the Earth’s true shape, which led to Cassini’s obstinate defiance of their findings. Celsius gave short shrift to Swedenborg’s ideas about magnetic declination. Linnaeus, a correspondent, recommended the flipping of the temperature scale shortly after Celsius’ death.
Regarded as the founder of modern chemistry and a champion of empirical experimentation, Boyle was committed to the explainability of the universe on mechanical principles. Ussher was an early mentor. Boyle became central to the experimentalist circle around Wilkins (including Wren, Ward, Locke, Willis and Lower), the nucleus of the future Royal Society. Hooke (a friend) and later Papin were his assistants. Oldenburg was a natural ally (Boyle published through him), Hartlib a close friend. Leibniz met him on a London visit; Leeuwenhoek, Fatio, Bayle and Aubrey all corresponded. Locke and Newton spent long hours discussing mystical ideas with him.
Beccaria was, in the early days of the field, one of the world’s leading exponents of electricity; sometimes better known for his promotion of his friend Franklin’s brilliant but more disorganised work, he taught some of the next generation’s leading lights — Lagrange, Galvani — although barely encouraging Volta when the 18-year-old wrote outlining his own ideas. Banks and Priestley corrresponded with him, as did Franklin (intesively), Lavoisier and Boscovich, while Burney (who described the sometimes-grouchy churchman as “large and noble”) became a friend in Turin. Bassi also corresponded, and collaborated on some experiments.
Boscovich, not as well known as he might be, held strikingly advanced ideas about space/time relativity and the nature of atoms, among much else. His wide-ranging correspondents included Euler, Jacobi, Bernoulli, Lagrange, Priestley, Spallanzani, Méchain, Metastasio and Voltaire. Old friends in France included Nollet, Lacaille, Lalande (struck by his extreme spirituality and profundity) and especially Clairaut, who admired his vast culture and personal dynamism. He met Buffon and Franklin, impressed Burney, discussed Newton with Johnson (in French and Latin), was initiated into the mysteries of Guy Fawkes’ Night by Maskelyne, and was resented by d’Alembert.
Crookes discovered an element, and did important work on cathode rays and spectroscopy. He studied with Hofmann, but Faraday, Wheatstone and Stokes nudged him towards chemical physics (a practical experimenter, Stokes and Maxwell often providing theoretical support). Crookes got on well with Tesla (telling him to go home to the mountains or he’d have a breakdown). He had a difference of opinion with Dewar, corresponded with Mendeleev, and told Galton that none of his (Crookes’) ancestors had any interest in science. Becquerel, Curie and Edison were all friends. He first met Faraday (less gullible about spiritualism) at a séance.
Gibbs helped found chemical thermodynamics, and did fundamental work on vector analysis (sparked by reading Maxwell), while his work in theoretical physics paved the way for quantum mechanics. Maxwell, one of the first to recognise Gibbs’ genius, later made and sent him a plaster model. Although Gibbs, self-contained, rarely travelled, his mailing-list of 300 prominent scientists included his correspondents Peirce, Rayleigh and Ostwald (who translated his work). In Germany he sat in on lectures by Kirchhoff, Helmholtz, Bunsen and Magnus (influences all); however it’s not known whether he actually met them.
Plücker did fundamental work in two very different fields: analytical geometry and cathode-ray physics (as well as in spectroscopy). Crelle promoted the young Plücker’s work, and helped him to an academic post, thus antagonising Plücker’s bête noire, the better-known but less original Steiner. Klein was Plücker’s doctoral student and assistant; he completed his unfinished work after his death. Plücker visited Wheatstone in his laboratory and saw his wave machine, corresponded with Faraday, was joined by Hittorf in his spectroscopic investigations, and served the visiting Helmholtz “remarkably good” wine.
Plateau is known for his research into vision and into the mathematics of soap-film surfaces, and for the development of early cinematic devices. Quetelet taught and befriended him, drew him into his scientific circle, and was generally strongly influential. Plateau met Arago in France, while sourcing good laboratory equipment (he probably met his fellow-researcher into colour, Chevreul, on the same trip). He adapted ideas of Faraday’s and Roget’s, Faraday — a friend — writing sympathetically in his blindness. Despite Plateau’s staring into the sun for experimental purposes, his eventual blindness probably had other primary causes.
Joule did fundamental research into work, heat, energy, and electrical resistance, and invented arc-welding. Dalton taught him for two important years. Easily his most important scientific friendship, close, collaborative, and life-long, was with Thomson, starting with a chance honeymoon meeting in Switzerland. Playfair was a Manchester colleague; they wrote some papers together, and Joule later sent him a supply of thermometers. Stokes, a correspondent, was early on converted to Joule’s theories; Tyndall however promoted his rival Mayer, the cause of personal friction. Helmholtz, visiting with Roscoe, was saddened by his decline.