The Life of Johannes Van Der Waals

Johannes Diderik van der Waals was born on November 23rd, 1837 in Leyden, The Netherlands. He died on March 8th, 1923, at the age of 85. His parents were Jacobus van der Waals, and Elisabeth van der Burg. He married Anna Magdalena Smit in 1864, and had four children, Anne Madeleine, Jacqueline Elisabeth, Johanna Diderica, and Johannes Diderik Jr. He worked as a school teacher in Leyden until he was later allowed to study at the university, despite a lack of knowledge of classical languages. He studied there from 1862 to 1865, and married Anna Smit in 1864. In 1866 he worked as a director in a secondary school of The Hague. Later, in 1873, he earned his doctorate degree, and then in 1876 was appointed the first professor of physics at the University of Amsterdam. He enjoyed walking and reading.

J.D. van der Waals’ first recognition came with the completion of his thesis, entitled Over de Continuïteit van den Gas- en Vloeistoftoestand, or “On the continuity of the gas and liquid state.” This work described how the gaseous and liquid states of matter are constantly merging into each other. The theory was considered revolutionary and controversial, as the existence of molecules was still being debated, the idea of their interactions with each other was unthought-of. His thesis also explained the gaseous and liquid states were also of the same nature. This became a major contribution to the later modified, “Equation of State.” It described the direct relation between volume, pressure, and temperature of matter in its gas or liquid state. The equation is commonly written, pV=nRT, in which p is pressure, V is volume, n is the number of moles of the compound, R is the universal gas constant, and T is temperature. R. Clausius used Mr. van der Waals formulas and ideas in his thesis about the critical pressures of gases.

In 1880 van der Waals published his Law of Corresponding States. This law explained that if one uses the critical pressure, volume, and temperature in the Equation of State that these variables, which apply to all substances, will cancel out, and one will obtain a simpler form of the equation. This simplified form was used to liquefy hydrogen by J. Dewar in 1898 and the liquefaction of helium by H. Kamerlingh Onnes. Onnes earned a nobel prize for his efforts, and gave attribution to van der Waals for his contributions in his own experiments.