cavendish experimentとは 意味・読み方・使い方

The Cavendish experiment, performed in 1797–98 by British scientist Henry Cavendish and inspired in part by observation of systematic surveying errors in the Mason Dixon line survey, was the first experiment to measure the force of gravity between masses in the laboratory, and the first to yield accurate values for the gravitational constant. Because of the unit conventions then in use, the gravitational constant does not appear explicitly in Cavendish's work. Instead, the result was originally expressed in terms of the specific gravity of the Earth (or equivalently, the mass of the Earth) which played the role of an inverse gravitational constant. The experiment was devised sometime before 1783 by geologist John Michell, who constructed a torsion balance apparatus for it. However, Michell died in 1793 without completing the work, and after his death the apparatus passed to Francis John Hyde Wollaston and then to Henry Cavendish, who rebuilt the apparatus but kept close to Michell's original plan. Cavendish then carried out a series of measurements with the equipment, and reported his results in the Philosophical Transactions of the Royal Society in 1798.