Solving mysteries of the universe after measuring gravity in the quantum world

A weak gravitational pull on a tiny particle using a new technique.


Gravity is best described as a curvature of space-time. Hence, it remains resistant to unifications with quantum theory. At microscopic scales, gravitational interaction is fundamentally weak and becomes prominent. It means that what happens to gravity in the microscopic regime where quantum effects dominate remains unknown, and whether quantum coherent effects of gravity become apparent remains unknown.

Thanks to new studies, scientists have successfully unraveled the mysterious forces of the universe. They figured out how to measure gravity on a microscopic level.

Using a new technique, they detected a weak gravitational pull on a tiny particle.

Their study could lead to new ways to find the elusive quantum gravity theory.

For this study, scientists used levitating magnets to detect gravity on microscopic particles – small enough to border the quantum realm. The results could help experts find the missing puzzle piece in our picture of reality.

Lead author Tim Fuchs, from the University of Southampton, said, “For a century, scientists have tried and failed to understand how gravity and quantum mechanics work together.

“Now that we have successfully measured gravitational signals at a negligible mass ever recorded, we are one step closer to finally realizing how it works in tandem.

“From here, we will start scaling the source down using this technique until we reach the quantum world on both sides.

“By understanding quantum gravity, we could solve some of the mysteries of our universe – like how it began, what happens inside black holes, or uniting all forces into one big theory.”

Scientists used a sophisticated setup involving superconducting devices, known as traps, with magnetic fields, sensitive detectors, and advanced vibration isolation.

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.

The results open the door for future experiments between even smaller objects and forces, said Professor of Physics Hendrik Ulbricht, also at the University of Southampton.

He added“We are pushing the boundaries of science that could lead to discoveries about gravity and the quantum world.

“Our new technique that uses frigid temperatures and devices to isolate the vibration of the particle will likely prove the way forward for measuring quantum gravity.

“Unravelling these mysteries will help us unlock more secrets about the universe’s fabric, from the tiniest particles to the grandest cosmic structures.”

Journal Reference:

  1. Tim Fuchs et al. Measuring gravity with milligram levitated masses. Science Advances. DOI: 10.1126/sciadv.adk2949