Thermodynamicsisaspecialtheoryindeed.Aprincipletheory, aphenomenological onemoreover, thatoutgrewitsinitialpurposeofadvancingnineteenthcentury engineeringalmostassoonasitwasborn1.Ceasingtobeameretoolforthe optimisationofsteamenginesandthelike, thermodynamicsinsteadbecameatheory about, well, 'almosteverything'.Butthisisnottosaythatthermodynamicscan provideuswiththeanswerstoallscientificquestions, quitethecontrary: traditionally, itfocussesonanarrowrangeofprocesses, singledoutbytheusageoftermssuchas heat, entropyandtemperature.Whatmakesthermodynamicssospecial, whatsets itapartfromotherphysicaltheories, isthecomprehensiveapplicationofitslawsto thoseothertheories.Quantuminformationtheory, quantumfieldtheory, general relativityandevenstringtheory, nottomentionchemistryandbiology-thelaws ofthermodynamicsareubiquitousamongourscientifi