Gravity, Geometry and the Quantum

I will begin with a broad perspective on the the conceptual problems of unifying the principles of general relativity and quantum mechanics, and then introduce loop quantum gravity, emphasizing the interplay between gravity, geometry and the quantum that lies at its foundation. This approach has resolved some of the long standing fundamental issues, such as: (i) What is the quantum nature of space-time geometry? (ii) Are singularities of classical general relativity naturally resolved and, if so, what is the consequent physics beyond Einstein? and (iii) How does one formulate and address physical questions when there is no classical spacetime in the background? In the second part of the talk, I will discuss some recent advances in quantum cosmology to illustrate that the approach has matured sufficiently to commence the creation of 2-way bridges between fundamental theory and observations. In contrast to, say, string theory where the focus appears to have shifted to creating a powerful toolkit for various branches of physics and mathematics, in loop loop quantum gravity, the focus continues to be on questions rooted in quantum gravity, proper. The talk will not assume prior knowledge of loop quantum gravity.