Leonard Ornstein
Dutch physicist (1880-1941)
Leonard Salomon Ornstein (12 November 1880 – 20 May 1941) was a Dutch physicist.
Education
Leonard Salomon Ornstein was born on 12 November 1880 in Nijmegen, Netherlands. He studied theoretical physics under Hendrik Lorentz at Leiden University. In 1908, he received his Ph.D. with a thesis concerning an application of the statistical mechanics of Josiah Willard Gibbs to molecular problems.
Career
In 1909, Ornstein became a lecturer in theoretical physics at the University of Groningen. In 1914, he succeeded Peter Debye as Professor of Theoretical Physics at Utrecht University. In 1920, he became Director of the Utrecht Physical Institute and extended his research interests to experimental subjects. His precision measurements concerning intensities of spectral lines brought the Physical Laboratory in the international limelight.
With Frits Zernike, Ornstein introduced in 1914 the integral relation now known as the Ornstein–Zernike equation. Developed while studying density fluctuations near the critical point of a fluid, the equation separates the total correlation between particles into a direct correlation and indirect correlations transmitted through other particles; it subsequently became a basic framework of equilibrium liquid-state theory.
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