Lessons from classical gravity about the quantum structure of spacetime
Abstract
I present the theoretical evidence which suggests that gravity is an emergent phenomenon like gas dynamics or elasticity with the gravitational field equations having the same status as, say, the equations of fluid dynamics/elasticity. This paradigm views a wide class of gravitational theories  including Einstein's theory  as describing the thermodynamic limit of the statistical mechanics of 'atoms of spacetime'. Strong internal evidence in favour of such a point of view is presented using the classical features of the gravitational theories with just one quantum mechanical input, viz. the existence of DaviesUnruh temperature of horizons. I discuss several conceptual ingredients of this approach.
 Publication:

Journal of Physics Conference Series
 Pub Date:
 July 2011
 DOI:
 10.1088/17426596/306/1/012001
 arXiv:
 arXiv:1012.4476
 Bibcode:
 2011JPhCS.306a2001P
 Keywords:

 General Relativity and Quantum Cosmology;
 Astrophysics  Cosmology and Extragalactic Astrophysics;
 High Energy Physics  Theory
 EPrint:
 Expanded version of the lectures given on several occasions including (i) Plenary talk at ERE 2010, Granada, September 2010