Why quantum theory and general relativity alone are insufficient to describe black holes and how this motivates the development of new theories of quantum gravity

Black holes provide one of the only naturally occurring extreme environments in which the predictions of general relativity and quantum mechanics no longer apply. When applied to the minuscule scale where quantum mechanics operates, general relativity breaks down and produces impossible infinities. This paper examines why the theories of general relativity and quantum mechanics are unable to explain the phenomena that occur in the presence of a black hole, and how this motivates new theories of quantum gravity that could explain these extreme instances where general relativity and quantum mechanics break down. This manuscript details the formation and growth of black holes themselves, and what makes them such a marvel of the natural world. It then discusses the classical prediction of black hole singularities, the implications of the Heisenberg Uncertainty Principle, and Hawking Radiation and the resulting information paradox. It then focuses on the emerging theories of quantum gravity such as String Theory and Loop Quantum Gravity and how they each try to reconcile quantum mechanics with gravitational phenomena. While neither theory has been experimentally confirmed, both demonstrate the ways in which quantum effects could modify our view of spacetime. Understanding these approaches may provide insight into how gravity can ultimately be incorporated into a quantum framework and contribute to a more complete description of the fundamental laws of the universe.