It is often claimed that Einstein's magnum opus---his 1915 theory of General Relativity---is distinguished from other theories of space and time in virtue of its background independence. It's also often claimed that background independence is an essential feature of any quantum theory of gravity. But are these claims true? This book aspires to offer definitive answers to both of these questions, by (a) charting the space of possible definitions of background independence, and (b) applying ...

As a child I found it quite difficult trying to sort out my own identity as a quasi-middle child. I say that because I had two sisters who were older and one sister just a year younger. I was the only male in the household other than my father. You would think that the situation would have worked in my favor since I was my father's only son. Believe it or not my situation worked completely opposite to the norm. My father had adopted a philosophy based on his own evolution as a child. Ironi...