Quantum scale gravity has long been a mystery to physics, but things could be starting to change.

 

Physicists measure the tiniest gravitational force ever

 

 

 

 

 

a new experiment that measured the miniscule gravitational attraction between two tiny gold spheres, each spanning just 2 millimeters across, could be the first of many to provide clues to how gravity operates at these scales.

"This was a proof-of-concept experiment to create a sensor capable of measuring very small accelerations and to establish methods that would allow us to detect even smaller gravitational forces," study co-author Jeremias Pfaff, a doctoral student at the University of Vienna, told Live Science. "Long-term, we'd like to answer what the gravitational field of a quantum object in a superposition looks like, but there is a lot to be done on the way there," said Pfaff, referring to the gravity experienced by a subatomic particle that is in two quantum states at once.

 To get a peek at how gravity works at small scales, the researchers used a tiny version of a torsion balance — a device first devised by English scientist Henry Cavendish in 1798 to measure the density of the Earth, and from it the strength of the gravitational constant called G.