This volume presents different approaches to quantum gravity, including loop quantum gravity, string theory, noncommutative geometry, canonical quantum gravity, and more advanced approaches. Coverage includes a discussion of the recent experimental status of the search for quantum gravity effects and is accessible to non-experts in the field. Extensive indexing of all articles ensures accessibility to keywords and phrases. The construction of a quantum theory of gravity is the most fundamental challenge confronting contemporary theoretical physics. The different physical ideas evolved in developing a theory of quantum gravity require highly advanced mathematical methods. Written by leading experts in this field, this book provides the reader with an overview of the different mathematical attempts to quantize gravity.