born Sept. 21, 1853, Groningen, Neth.
died Feb. 21, 1926, Leiden
Dutch physicist.
He taught at the University of Leiden (1882–1923), and in 1884 he founded the Cryogenic Laboratory (now known by his name) that established Leiden as the world's principal research centre for low-temperature physics. He was the first to produce liquid helium (1908), and he discovered superconductivity. He also investigated the equations describing the states of matter and the general thermodynamic properties of fluids over a wide range of temperatures and pressures. He was awarded the 1913 Nobel Prize for Physics.