Quantum gravity attempts to combine Einstein’s general theory of relativity with quantum mechanics. Quantum corrections to classical gravity are visualized as loop diagrams, as the one shown here in white. Alternatively, it’s possible that gravity is always classical and continuous, and that quantum field theory, not general relativity, needs to be modified. (Credit: SLAC National Accelerator Laboratory)
Physicists just can’t leave an incomplete theory alone; they try and repair it. When nature is kind, it can lead to the next major breakthrough.
In physics, many of our greatest advances aren’t driven merely by data that conflicts with our best theories, but rather by noticing that two disparate aspects of our best current understanding simply don’t “play nice” with one another. Paying attention those those inconsistencies often helps us realize how our current theories are, in fact, “incomplete” in a fundamental sense, and the quest to find a more complete version of them often bears a tremendous amount of fruit as far as bringing about the next step forward in our understanding of the Universe.
This has happened many times throughout history, and led to the development of a number of important advances in theoretical physics, including:
