Physical chemist Benjamin Widom, at Cornell University, proposes in 1965 a specific form for the equation of state of a fluid near its critical point (the point where two phases of a substance, such as water and steam, lose their distinguishing features and behave as one). He introduces a function depending on a measure of temperature and one of density, and suggests that in a real fluid this function is homogeneous: it has the same mathematical form at any observational scale near the critical point. This scaling hypothesis unifies a series of empirical relations among the critical exponents — numbers describing how certain physical quantities (compressibility, specific heat, magnetization) diverge upon approaching the critical point — which until then had been observed experimentally with no common theoretical justification. Widom's work does not yet offer a physical mechanism explaining why free energy should behave in this homogeneous way, but it establishes the exact mathematical form any later theory would have to reproduce. This piece is the explicit starting point of the entire theoretical chain the Wolf Prize committee would recognize fifteen years later in Wilson, Kadanoff, and Fisher: Leo Kadanoff, the following year (1966), provides the missing physical justification via the idea of "block spins"; Kenneth Wilson, in 1971, formalizes that idea in the renormalization group, explicitly citing the "Widom-Kadanoff scaling laws" as the result his differential equations had to reproduce.