Padmanabhan, T.2012-08-112012-08-112012-03-28http://hdl.handle.net/11007/2154Just as the thermal properties of normal matterdemandsthe existence of microscopic degrees of freedom, the thermal properties of null surfaces — perceived as local Rindler horizons by accelerated observers — demands the existence of microscopic degrees of freedom to spacetime. The distortion of the null surfaces, just like the deformation of an elastic solid, costs entropy. I show how, just like in the case of an elastic solid, one can describe the dynamics of thespacetime solid by introducing an entropy density to the distortion of null surfaces in the spacetime.enSecret LifeSpacetimeArticle