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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?

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# Gibbs and Maxwell's U-S-V surface

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