Abstract:
A natural guiding principle for gravitational dynamics is that the field equations should remain invariant under the shift of the zero level of energy. I show that this implies a thermodynamic interpretation for gravity, thereby connecting two physical concepts usually treated as separate. This approach leads to a thermodynamic variational principle for gravity and the geometrical variables, as well as the evolution equation for the spacetime, acquire a thermodynamic interpretation. Extending these ideas one level deeper, the relevant variational principle can be obtained from a distribution function for the "atoms of space". This is based on the curious fact that, in the renormalized spacetime, each event has zero volume but finite area!
