Researchers have observed the effects of gravity on a microscopic level, paving the way for further investigation into its behavior in the enigmatic quantum realm.

During a complex experiment, scientists used advanced superconducting equipment that was cooled to almost absolute zero. They also attached brass weights to an electric bicycle wheel. The researchers observed a tiny gravitational pull of 30 quintillionths of a newton on a particle that was less than one millimeter in size.

The presentation sets the stage for future studies where scientists hope to gauge the gravitational pull of increasingly smaller particles to gain insight into the behavior of this unconventional force in the subatomic realm, where quantum principles reign.

According to Tim Fuchs, a postdoctoral experimental physicist at the University of Southampton, it is currently impossible to reconcile quantum mechanics and general relativity, which is Einstein’s theory of gravity. This suggests that one or both theories need to be adjusted. To address this issue, experiments are being conducted to provide further insights.

Physicists have been attempting to merge gravity, which explains how mass affects space and time, with quantum theory, which governs the behavior of subatomic particles, for over a hundred years. Exploring the quantum aspects of gravity could potentially unlock answers to major mysteries in the universe, such as its origins and the mechanics of black holes. Despite numerous theories proposed by researchers, conducting experiments to determine which theory is correct has been challenging.

Researchers from Leiden University and the Institute for Photonics and Nanotechnologies in Italy have developed a method to detect minute gravitational forces between small objects.

The experiment, which was heavily protected against interference from vibrations, centred on a magnetic particle that was levitated above a superconductor cooled to one hundredth of a degree above absolute zero, or -273.15C, the coldest temperature possible in the universe. The almost negligible pull on the hovering particle was then measured as an electrical bicycle wheel fitted with brass weights revolved about a metre away, bringing the weights near to the particle and then back again.

Fuchs explained that when the wheel is spun, it sets the particle in motion similar to a swing. The gravitational force initially pulls on the particle, then releases it, before pulling on it again.

The strength of the gravitational pull between two objects is determined by their masses and the distance separating them. The force of attraction increases as the objects’ masses and proximity increase.

In a publication in Science Advances, the scientists explain how they used a 30-attonewton force to delicately manipulate a particle weighing half a milligram in their study. An attonewton is equivalent to one billionth of a billionth of a newton. According to Fuchs, this is not yet considered quantum gravity, but it is a significant step in that direction, as reported by the Guardian.

After proving the functionality of the equipment, the scientists aim to observe the behavior of gravity among increasingly smaller particles that are governed by the principles of quantum mechanics. However, this process will require some time as it could take five to ten years for the initial measurements to be conducted, according to Fuchs. He emphasized the importance of conducting experiments in order to gather more information on this topic.

Source: theguardian.com