Uncovering Quantum Gravity – Scientists crack the cosmic code that puzzled Einstein

Physicists have successfully measured gravity in the quantum world, discovering the weak gravitational pull on a small particle using a new technique that uses suspended magnets, bringing scientists closer to solving the mysteries of the universe.

Scientists are one step closer to unraveling the mysterious forces of the universe after figuring out how to measure gravity at the microscopic level.

Experts have never fully understood how the force discovered by Isaac Newton works in the tiny quantum realm.

Even Einstein was puzzled by quantum gravity, and said in his theory of general relativity that no realistic experiment could show a quantum version of gravity.

A breakthrough in quantum gravity

However, physicists at the University of Southampton, working with scientists in Europe, have succeeded in detecting a weak force of attraction on a small particle using a new technique.

They claim that this could pave the way for finding the elusive theory of quantum gravity.

Experience published in Advancement of science magazine, used high-powered magnets to detect gravity on microscopic particles — small enough to challenge the quantum realm.

Artist's impression of the quantum experiment. Credit: University of Southampton

Pioneering gravity research

Lead author Tim Fox, from the University of Southampton, said the findings could help experts find the missing piece of the puzzle in our picture of reality.

He added: “For a century, scientists have tried and failed to understand how gravity and quantum mechanics work together.

“We have now succeeded in measuring gravitational signals at the smallest mass ever recorded, meaning we are one step closer to understanding how gravity works in tandem.

“From here we will start reducing the size of the source using this technique until we reach the quantum world on both sides.

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

The rules of the quantum world are still not fully understood by science, but particles and forces at the microscopic level are thought to interact differently than with normal-sized objects.

Academics from Southampton conducted the experiment with scientists at Leiden University in the Netherlands and the Institute of Photonics and Nanotechnology in Italy, funded by an EU Horizon Europe EIC Pathfinder (QuCoM) grant.

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

A weak pulling force, only 30 amperes, was measured on a particle as small as 0.43 mg by holding it at freezing temperatures up to one-hundredth of a degree above. Absolute zero – About -273 degrees Celsius.

Expanding the horizons of quantum research

Physics professor Hendrik Ulbricht, also at the University of Southampton, said the results open the door to future experiments between smaller objects and forces.

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

“Our new technology that uses cryogenic temperatures and devices to isolate particle vibration is likely to prove the way forward for measuring quantum gravity.

“Unraveling these mysteries will help us uncover more secrets about the fabric of the universe, from the smallest particles to the largest cosmic structures.”

Reference: “Measuring Gravity with Lifted Masses in Milligrams” by Tim M. Fox, and Dennis J. Uitenbroek, Jimmy Plug, Noud van Halteren, Jean-Paul van Soest, Andrea Venanti, Hendrik Ulbricht, and Tjerk H. Osterkamp, ​​February 23, 2024, Advancement of science.
doi: 10.1126/sciadv.adk2949