Scientists have successfully detected the quantum gravity of a tiny particle with a new technique that uses levitating magnets.
Physicists are a step closer to finding out the mysterious forces of the Universe after working out how to measure quantum gravity.
Experts have never understood how the force works on a microscopic level.
In Einstein’s theory of general relativity, he argued that there is no realistic experiment that could show a quantum version of gravity.
Now, scientists at the University of Southampton, in collaboration with European physicists, have detected a weak gravitational pull on a tiny particle.
The team argues that it could pave the way to finding quantum gravity theory.
Published in Science Advances, the work used levitating magnets to detect gravity on microscopic particles – small enough to border the quantum realm.
Understanding quantum gravity
The work could help experts find the missing puzzle piece in our picture of reality.
Lead author Tim Fuchs from the University of Southampton stated: “For a century, scientists have tried and failed to understand how gravity and quantum mechanics work together.
“Now we have successfully measured gravitational signals at a smallest mass ever recorded, it means we are one step closer to finally realising 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.”
Although the rules of the quantum realm are not fully understood by science, it is believed that particles at a microscopic scale interact differently than regular-sized objects.
Measuring the pull of particles on a microscopic scale
Academics from Southampton conducted the experiment with physicists at Leiden University in the Netherlands and the Institute for Photonics and Nanotechnologies in Italy.
The work received funding from the EU Horizon Europe EIC Pathfinder grant.
The team used superconducting devices, known as traps, with magnetic fields, sensitive detectors, and advanced vibration isolation.
It measured a weak pull – 30aN – on a tiny particle 0.43mg in size by levitating it in freezing temperatures a hundredth of a degree above absolute zero, about -273°C.
Paving the way for future experiments
The results pave the way for future experiments between even smaller objects and forces.
Hendrik Ulbricht, Professor of Physics at the University of Southampton, said: “We are pushing the boundaries of science that could lead to new discoveries about gravity and the quantum world.
“Our new technique that uses extremely cold temperatures and devices to isolate 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 very fabric, from the tiniest particles to the grandest cosmic structures.”
