Einstein’s general relativity is an exceptional theory of gravity that has been proven correct time and time again. Quantum mechanics takes care of the three other fundamental forces, and it too has been exceptionally successful over the last century.

Gravity is the most familiar of nature’s forces. It keeps our feet planted on the ground and dictates the movements of planets and stars. Yet, even so, gravity remains one of the greatest mysteries in physics.

Diagrammatic representation of the entropic quantum gravity action. The action for gravity is given by the quantum relative entropy between the metric

For decades, physicists have struggled to reconcile the laws governing the very small with those that describe the vast cosmos. Quantum mechanics rules subatomic particles, while general relativity explains gravity’s role in shaping space and time.