China News Service, Beijing, March 11 (Reporter Sun Zifa) The internationally renowned academic journal "Nature" recently published an important research paper on physics, saying that researchers used two small golden balls with a radius of 1 millimeter (mm) to achieve the smallest gravitation so far. Field measurement may pave the way for future experiments to explore new areas of basic physics, such as exploring dark matter or the interaction between quantum physics and gravity.

Gravity can be understood as a distortion from space-time, as shown in this artistic concept map.

Picture from Arkitek Scientific.

Photo courtesy of Springer Nature

  The paper introduced that gravity is a basic force, but people's understanding of gravity has been incomplete; gravity cannot be included in the Standard Model of physics, and it seems to be incompatible with quantum theory.

Measuring the coupling force of gravitational forces between extremely small objects may provide some insights into this mysterious force, such as deviations from the predictions of Newton's theory of gravity.

However, it is very difficult to carry out this kind of test, and strict environment needs to be controlled to ensure that disturbances from other sources and gravity itself are minimized.

  Corresponding author of the paper, Markus Aspelmeyer of the University of Vienna, Austria, and colleagues designed an experiment to make gravity appear as a coupling force between two small golden balls with a mass of about 90 milligrams (mg). .

This strictly controlled experiment minimized the influence of external disturbances.

For example, in this experiment, a Faraday shield was used to block electrostatic forces, and one of the golden balls was connected to a vacuum chamber to minimize earthquake and sound effects; the other ball would periodically approach the grounded ball, thereby reducing the gravitational force. The coupling is separated separately so that it can be detected from changes in the rotation signal.

The researchers used two golden balls with a radius of 1mm to measure gravity. The picture is from Tobias Westphal of the University of Vienna.

Photo courtesy of Springer Nature

  This experiment confirmed the classic Newtonian theory of physics, that the gravitational force between two balls depends on their mass and distance.

The authors of the paper believe that there is room for further improvement in the sensitivity of their experiments, and it is expected that the gravitational force between smaller objects can be measured in the future.

  The author of the paper said that such experiments may allow researchers to test basic physics that has yet to be explored, including the gravitational effects of dark matter and the gravitational coupling between quantum systems.

However, incorporating quantum physics into this type of test is still quite challenging.

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