Michael Widom, "Information-theoretic approaches to calculating thermodynamic entropy"Join us on November 29 at 2:30pm in White Hall G09 for a colloquium presented by Dr. Michael Widom, professor of physics at Carnegie Mellon University. He will speak on Information-theoretic approaches to calculating thermodynamic entropy . Continue reading for Dr. Widom's abstract.
The thermodynamic entropy of matter equals (in suitable units) the information required to precisely specify its state. In a fully random substitutional alloy of N chemical species, log(N) bits of information per site are required to specify the site occupations. In an ideal gas of volume V, the information required to locate each molecule grows as log(V). If the alloy is not fully random, or the gas is not ideal, then prior information contained in positional correlations becomes redundant, and the thermodynamic entropy falls below its ideal value to a quantifiable extent. We will illustrate practical applications of this principal that allow us to model phase separation and eutectics in liquid alloys; the substitutional entropy of high entropy alloys; and the HCP/BCC transition of elemental titanium.