## Are Space, Time, And Gravity All Just Illusions?

“Sound waves emerge from molecular interactions; atoms emerge from quarks, gluons and electrons and the strong and electromagnetic interactions; planetary systems emerge from gravitation in General Relativity. But in the idea of entropic gravity — as well as some other scenarios (like qbits) — gravitation or even space and time themselves might emerge from other entities in a similar fashion. There are well-known, close relationships between the equations that govern thermodynamics and the ones that govern gravitation. It’s known that the laws of thermodynamics emerge from the more fundamental field of statistical mechanics, but is there something out there more fundamental from which gravity emerges? That’s the idea of entropic gravity.”

There are many attempts out there to reconcile the quantum field theories that describe the electromagnetic and nuclear forces with general relativity, which describes the gravitational force. Certain questions, about gravitational properties in strong fields and on small scales, will never be answered otherwise. In order to make that happen, we’d need a quantum theory of gravity. While string theory is the most popular idea, there are others, such as asymptotic safety, loop quantum gravity, and causal dynamical triangulations. But perhaps the most radical idea came from Erik Verlinde in 2009: the idea that gravity itself is not fundamental, but rather arises from a truly fundamental entity: the entropy of quantum bits of information. Verlinde’s work has been intriguing and especially controversial, and I myself have spotted a number of problem areas with his results so far, but it’s certainly an idea worth exploring further. At 7 PM ET / 4 PM PT tonight, he delivers the Perimeter Institute’s inaugural public lecture of their 2017-2018 series.