A New Theory of Gravity Could Provide a Breakthrough in Physics
For over a century, physicists have grappled with the challenge of unifying quantum mechanics and general relativity. While both theories have been refined and extensively tested, they alone cannot fully explain everything – and together, they don’t seem to work. This has led to the search for a grand unified theory, with string theory and quantum loop gravity being the main contenders. Now, a group of researchers has proposed a new theory that challenges the traditional understanding of space-time.
Dubbed the “postquantum theory of classical gravity,” this new theory has been in development for five years and has now been presented to the scientific community. What sets it apart from its predecessors is that space-time is not quantized, challenging the assumption that space-time is made up of discrete steps.
In a statement, Professor Jonathan Oppenheim of University College London explained, “Quantum theory and Einstein’s theory of general relativity are mathematically incompatible with each other, so it’s important to understand how this contradiction is resolved. Now that we have a consistent fundamental theory in which space-time does not get quantized, it’s anybody’s guess.”
One of the key features of the postquantum theory of classical gravity is the prediction of violent energy fluctuations in space-time that give rise to the creation and disappearance of particles and antiparticles. These fluctuations are expected to be even more violent compared to the quantized space-time picture, providing a way to test the theory.
The team of researchers has outlined a method to test the theory by measuring the mass and weight of an object with high precision. By observing fluctuations in the measured weight over time, they can determine if space-time is classical. If these tiny changes are not observed, it would rule out the postquantum theory of classical gravity.
While testing the theory is not something that can be done overnight, the researchers estimate that it could be tested within two decades. This is significant as there is a bet between proponents of other theories, quantum loop gravity and string theory, on whether space-time is quantized.
The main paper presenting the theory has been published in Physical Review X, and a second paper outlining how to test the theory has been published in Nature Communications. If the postquantum theory of classical gravity proves to be viable, it could represent a major breakthrough in our understanding of the universe and the fundamental forces that govern it.