Constantin Miculescu

Constantin Miculescu (1863 - 1937), great Romanian physicist.


He was born in Creveniciu village, Teleorman County. Outstanding student in primary school, he continue his studies at "Matei Basarab" College in Bucharest (colleague and friend of Gheorghe Marinescu, the future founder of the Romanian school of neurology), then at the Faculty of Science, Department of Physics-Mathematics in Bucharest. Here, Miculescu enjoyed the appreciation of great teachers as Spiru Haret, Marin Alexe, Emanuel Bacaloglu - the last one helped the brilliant student to obtain in 1886 a scholarship at Sorbonne University, Paris. In 1893 he obtained the PhD with a thesis in which he put forward both a sense of mathematical precision, and inventiveness.

The great physicist James Prescott Joule had determined the mechanical equivalent of the calories, a fundamental constant for physics and especially for thermodynamics. But his calculations, and other great physicists too, gave inaccurate results, with differences of up to 20% between them, and therefore unusable in practice. Miculescu instead made a totally original calorimeter, with which he measured, through a personal process, the most precise mechanical equivalent of calories: J = 4.1857, which could be included in the international tables and used as a physical constant. When, in 1950, after almost six decades, the International Committee of Weights and Measures has established the definitive value, the correction affected only the fourth decimal place (4.1855, instead of 4.1857). The 1891 experience of Miculescu became famous and is today cited not only in physics treaties, but also in school textbooks around the world, many presenting and outline its device.

Returned in Romania in 1891, when Em. Bacaloglu was dead, Constantin Miculescu was called to replace him at the Department of Physics, University of Bucharest, where he taught from 1891 until 1935, being one of founders of modern physics school in Bucharest. He developed a method for measuring the inside diameter of capillary tubes (very narrow), he created a very precise method for measuring the refractive index of a solid body with prism shape using the microscope, he developed a method for determining the coefficient of elasticity of bodies by an acoustic method...

In 1909 was elected member of the International Committee for Establishment of Physical Constants. It was the first Romanian physicist who has imposed worldwide through a major contribution - fundamental to modern thermodynamics. A prize of the Romanian Academy today bears his name, and his bust is located inside the University of Bucharest, designed by sculptor Corneliu Medrea.