Hi all, A few weeks ago I found http://www.sv.vt.edu/classes/ESM4714/methods/Gibbs.html" [Broken] by Dr. Kriz of Virginia Tech. He describes how Gibbs envisioned a 3D U-S-V (energy-entropy-volume) surface, from which Maxwell created a sculpture. Maxwell believed the surface was of great importance: "Gibbs and Maxwell continued to use the graphical method to develop the thermodynamic theory of state by asking the question: What thermodynamic processes exist when moving from point A to point B on the energy-entropy-volume diagram?" (Kriz) I have been unable to find much information about this surface outside of the above website and the original papers of Gibbs/Maxwell. I was hoping to discover thermodynamic relationships this surface may help visualize. I have created a 3D model of the surface (I can attach the .blend file when I get to the computer lab) that allows many different perspectives. The relationships this graph provides: U-V-S, U-w-q Isotherms, Isobats, Isochores, Constant Entropy Phase changes Gibbs free energy (if you have a point below the surface, the Gibbs free energy is the vertical distance to the surface) Capacity for entropy (like above, only horizontal distance) and many more Can anyone provide insight into this surface?