Job For Particle Accelerators May Be Possible on Tabletop
Testing whether gravity obeys the laws of classical physics or quantum mechanics is no easy matter. Discovering mineral deposits from space and etching atom-sized lithographs aren’t exactly simple either. But all three tasks may soon belong to a quantum phenomenon called the Bose-Einstein Condensate (BEC).
Perhaps most dramatic is the downsizing BECs enable of a role physicists had mused might require an absurdly huge and expensive particle accelerator the size of the Milky Way galaxy. Yet, recent research proposals suggest that a tiny, super-cooled cloud of atoms could provide a more practical tabletop experiment that probes the mystery of whether gravity is classical or quantum in nature.
The proposed experiment would harness a Bose-Einstein condensate—billions of atoms cooled to near absolute zero so that they behave like a single large atom from a quantum mechanics standpoint—within a millimeter-sized spherical trap and see how it reacts to its own gravitational pull. If gravity is classical in nature, the chilled cloud of atoms can only follow a classical-like probability distribution under the influence of its own gravitational pull. But if gravity is quantum in nature, the cloud of atoms could change from its initial classical-like probability distribution to a quantum-like probability distribution.
“Using tabletop experiments seems like the only foreseeable possibility to test quantum gravity in the lab,” says Richard Howl, a physicist and research fellow at the University of Hong Kong.