Today is the birthday of physicist Johannes van der Waals, who was born in 1837 in Leiden, Netherlands. He was largely self-taught, having become a schoolteacher after completing his elementary education. In his spare time he studied at Leiden University, and in 1873 he received his doctorate in physics after developing an equation of state to describe liquids and gases. Van der Waals's thesis established him as the leader in the study of thermodynamics. He also adapted the ideal gas law to accommodate molecules and intermolecular forces—before anyone had definitively proven that molecules exist. The weak attractive force between neutral molecules in fluids and other substances are now known as Van der Waals forces. He was awarded the 1910 Nobel Prize in Physics.
