Heat Death

Simon Schaffer

• Ludwig Boltzmann: The Man who Trusted Atoms by Carlo Cercignani
  Oxford, 329 pp, £29.50, September 1998, ISBN 0 19 850154 4

The Second Law of Thermodynamics has an oddly talismanic status in the public life of physics. Flanders and Swann wrote a song about it; C.P. Snow lectured on it. Whether it refers to the impossibility in a sealed system of letting heat flow from a cooler to a hotter body, or to the tendency of the universe to run down to more chaotic and disorderly states, it forms a key element in the magnificent edifice of the science of heat and energy constructed in the closing decades of the 19th century. Snow apparently thought it fairly easy to describe, and in a strange version of the humiliation game reckoned that to confess ignorance of the Second Law was like an admission that one had never read Shakespeare. His literary dinner companions’ response was suitably thermodynamic – ‘cold and negative’ – convincing him that they were all fatally and stupidly antiscientific.