Boškovic, Rudjer Josip

Born May 18,1711, in Ragusa (now Dubrovnik), Yugoslavia; died Feb. 13, 1787, in Milan. Croatian physicist, mathematician, and astronomer.

Bošković studied at the Collegium Romanum, where he became a professor of mathematics in 1740. From 1764 to 1770 he was a professor at the University of Pavia. In 1773, Bošković became a French subject, and from 1773 to 1783 he occupied the post of director of the optical section of the French Navy. Bošković measured a meridian arc of two degrees passing through Rome and Rimini. He also studied the earth’s shape and problems of theories about comets. He perfected astronomical instruments (the Rochon micrometer and others). In his principal work A Theory of Natural Philosophy Reduced to a Single Law of the Forces Which Exist in Nature (1758), he first developed the theory of the structure of matter based on the concept of nonextended, indivisible, identical material points, between which forces act that are subordinate to a universal law. At short distances between the points, the interactive force would be one of repulsion, infinitely increasing as the points approach one another; with an increase in the distance between points, their interactive force would revert to zero and then change signs; a force of attraction would originate which would first increase, and then, as the distance becomes greater, would pass through zero several times and change signs. At great distances, Bošković’s law merges with Newton’s law of gravitation. With the aid of this hypothesis, Bošković explained elasticity, resistance, plasticity, and several other properties of bodies. In applying his law on the universe Bošković admitted the possibility of its gradual contraction and expansion during corresponding changes in the scale of forces, which, therefore, would not cause any perturbations in the observable phenomena. Bošković also developed the doctrine of the relativity of the measurements of space and time. His ideas exerted a great influence on physicists during the first half of the 19th century.