Amazing stuff! What is e.g. the gravity force of an electron?
"... In a recent experiment, researchers ... levitated tiny particles with magnets and measured their gravitational pull at near absolute zero temperatures to minimize external noise. The mass of the particles measures a mere 0.000015 ounce (0.43 milligrams). Much to their surprise, this setup allowed the physicists to detect a faint whisper of gravity.
“We have successfully measured gravitational signals at the smallest mass ever recorded,” ..."
"... They claim it could pave the way to finding the elusive quantum gravity theory. ...
It measured a weak pull, just 30aN, on a tiny particle 0.43mg in size by levitating it in freezing temperatures a hundredth of a degree above absolute zero – about minus-273 degrees Celsius. ..."
From the abstract:
"Gravity differs from all other known fundamental forces because it is best described as a curvature of space-time. For that reason, it remains resistant to unifications with quantum theory. Gravitational interaction is fundamentally weak and becomes prominent only at macroscopic scales. This means, we do not know what happens to gravity in the microscopic regime where quantum effects dominate and whether quantum coherent effects of gravity become apparent. Levitated mechanical systems of mesoscopic size offer a probe of gravity, while still allowing quantum control over their motional state. This regime opens the possibility of table-top testing of quantum superposition and entanglement in gravitating systems. Here, we show gravitational coupling between a levitated submillimeter-scale magnetic particle inside a type I superconducting trap and kilogram source masses, placed approximately half a meter away. Our results extend gravity measurements to low gravitational forces of attonewton and underline the importance of levitated mechanical sensors."
P.S. It is very annoying that popular science articles do not reveal the source of their information as happened again here. I made the effort again to find the official news release! This is clearly bad practice!
Scientists closer to solving mysteries of universe after measuring gravity in quantum world (official news release) Scientists are a step closer to unravelling the mysterious forces of the universe after working out how to measure gravity on a microscopic level.
Measuring gravity with milligram levitated masses (open access)
Fig. 1. Schematic depiction of the experimental setup.
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