Adiabatic thermodynamics of fluids : from hydrodynamics to general relativity This book exists because there is (or was) no satisfactory theory of the dynamical metric interacting with extended distributions of matter. It will be shown that any theory of interacting fields that includes the Einsteinian metric must be based on an action principle. This allows us for the first time to use energy as a precise concept in vortex dynamics. Sample applications include rotating planets Couette flow tresses in fluids (inside the meniscus negative pressures) immiscible fluids amongst others. Unlike the traditional approach to thermodynamics this book begins with a brief exposition of hydrodynamics. At this stage the development is limited to potential flows because until recently that is all that could be done but also for didactic reasons. However the reader will find that the situation has changed radically with the discovery of the Conservative Hydrodynamics. At the core of thermodynamics is the Gibbsean minimum energy principle. In this book it is generalized to include the hydrodynamical degrees of freedom; that is localized as a field theory of density pressure temperature and entropy. The theory is referred to as local as opposed to traditional global thermodynamics where the main foundation is the variational principle of Gibbs with a modification recommended by Prigogine Action principle for thermodynamics Localization Applications to simple systems A theory of fluid mixtures Immiscible fluids Speed of sound in mixtures Superfluid helium part A Atmospheres Conservative hydrodynamics Rotating planets Special relativity General relativity.