Perhaps the most intriguing endeavor in modern science is the ongoing work to unify the laws of physics at the very largest and smallest scales. That means finding a way to combine gravity with the laws of quantum mechanics to create a theory of quantum gravity.
One of the big ideas at the heart of this work is that the boundary of our cosmos contains all the information to describe what goes on within the universe. That’s weird because the boundary is only two dimensional while the universe is three-dimensional. Somehow, the extra dimension emerges from the properties of the other dimensions.
Physicists call this holographic duality because it is similar to the way that a third dimension appears in two dimensional holograms. The idea that we live in an emergent spacetime has captured the attention of numerous physicists, who would dearly like to explore this notion further.
