Johannes Diderik van der Waals was a Dutch scientist and thermodynamicist famous for his work on the equation of state for gases and liquids which describe the relation between the pressure, volume, and temperature of fluids (gases and liquids). In 1873 he obtained his doctor's degree at Leiden University for a thesis entitled Over de Continuïteit van den Gas- en Vloeistoftoestand (On the continuity of the gas and liquid state). In this thesis he derived the equation of state bearing his name. This work gave a model in which the liquid and the gas phase of a substance merge into each other in a continuous manner. It shows that the two phases are of the same nature. In deriving his equation of state van der Waals assumed not only the existence of molecules (which in physics was disputed at the time), but also that they are of finite size and attract each other. Since he was one of the first to postulate an intermolecular force, however rudimentary, such a force is now sometimes called a van der Waals force.

A second great discovery of van der Waals was published in 1880: The Law of Corresponding States. This law shows, that after scaling temperature, pressure, and volume by their respective critical values, a general form of the equation of state is obtained which is applicable to all substances. This law served as a guide during the experiments that led to the liquefaction of helium by Heike Kamerlingh Onnes.

Van der Waals found his incentive for his life's work after reading the 1857 treatise by Rudolf Clausius entitled Über die Art der Bewegung welche wir Wärme nennen (On the Kind of Motion we Call Heat). Van der Waals was later greatly influenced by the writings of James Maxwell, Ludwig Boltzmann, and Willard Gibbs. For his work he won the 1910 Nobel Prize in physics.... More • http://en.wikipedia. ... _der_Waals View • Books • Images • Videos • Search Related • Scientists • 1890s • 1910s • Netherlands • November 23 • Physicists • Physics • Sagittarius • People