Testing quantum gravity

The search for a theory of quantum gravity is the most fundamental problem in all of theoretical physics, but there are as yet no experimental results to guide this endeavor. In this article we show a potential way out of this deadlock, utilizing macroscopic quantum systems; superfluid helium, gaseous Bose-Einstein condensates and “macroscopic” molecules. It turns out that true quantum gravity effects could and should be seen (if they occur in nature) using existing technology, making quantum gravity enter the realm of testable, potentially falsifiable theories, i.e. becoming real physics after almost a century of pure theorizing. The “holy grail” of fundamental theoretical physics is quantum gravity the goal of somehow reconciling gravity with the requirement of formulating it as a quantum theory, i.e. “explaining” how gravity as we presently know it emerges from some more fundamental microscopic theory. The most serious obstacle from the point of view that physics is supposed to be a natural science telling us something about the real world is the total lack of experiments guiding us. Today there are as yet no detected observational or experimental signatures of quantum gravitational effects. Naively, essentially from pure dimensional analysis arguments, quantum gravity experimentally requires an energy of roughly EP = √ h̄c5/G ≃ 10 eV, the “Planck Energy” (or equivalently, the means for exploring length-scales of the order of ∗[email protected]