An elusive theory that would unify general relativity with quantum mechanics. No self-consistent theory of quantum gravity has yet been found, despite great theoretical efforts.
General Relativity, Quantum Mechanics
References
Ashtekar, A. Lectures on Non-Perturbative Canonical Gravity. Teaneck, NJ: World Scientific, 1991.
Christensen, S. M. (Ed.). Quantum Theory of Gravity: Essays in Honor of the 60th Birthday of Bryce S. DeWitt. Bristol, England: A. Hilger, 1984.
Isham, C. J.; Penrose, R.; and Sciama, D. W. (Eds.). Quantum Gravity 2: A Second Oxford Symposium. Oxford, England: Oxford University Press, 1981.
Markov, M. A. and West, P. C. (Eds.). Quantum Gravity. New York: Plenum, 1984.
Prugovecki, E. Principles of Quantum General Relativity. River Edge, NJ: World Scientific, 1995.
Weisstein, E. W. "Books about Quantum Gravitation." http://www.ericweisstein.com/encyclopedias/books/QuantumGravitation.html.
Wolfram, S. A New Kind of Science. Champaign, IL: Wolfram Media, pp. 1054-1055, 2002.
