Experiment records minuscule gravitational pull as a step to understanding how force operates at subatomic level

Scientists have detected the pull of gravity on the microscopic scale in a feat that lays the groundwork for probing its nature in the mysterious quantum realm. In an experiment involving sophisticated superconducting apparatus cooled to within a whisker of absolute zero, and brass weights stuck to an electrical bicycle wheel, physicists recorded a minuscule gravitational tug of 30 quintillionths of a newton on a particle less than a millimetre wide. The demonstration paves the way for future work in which researchers aim to measure the gravity generated by ever smaller particles to understand how the unusual force behaves in the subatomic world where quantum rules dominate. ....