How does the integration of quantum field theory and general relativity enhance our understanding of fundamental particles and the dynamics of the universe? Additionally, in the quest for a unified theory of physics, how do string theory, loop quantum gravity, and other theoretical frameworks address the fundamental discrepancies between quantum mechanics and general relativity, such as the nature of space - time at the Planck scale? Moreover, what experimental evidence or observational phenomena could provide insights into the validity of these theories, and how might they reconcile the inconsistencies between quantum mechanics and general relativity on both cosmological and subatomic scales?