Einstein's Theory Confirmed Again: Spacetime Curvature Measured

Chinese scientists have published the most precise measurement results confirming Albert Einstein's general theory of relativity in practice. According to a study published in Nature, specialists from the Wuhan Institute of Physics and Mathematics have managed to record how Earth's mass "curves" spacetime with record-high precision. This achievement is an important step for modern physics and helps constrain alternative theories. This is reported by Ixbt.com reports .

According to Ixbt.com, the measurement error was only 0.2 percent. For comparison, all previous attempts had uncertainties reaching up to 10 percent. This refers to the "frame-dragging effect of inertial reference frames," or the "Lense-Thirring effect," named after the physicists who modeled it in 1918. According to this phenomenon, the more massive an object is and the faster it rotates, the more strongly it distorts the space around it.

Measurements using a unique satellite

To detect these extremely weak gravitational deviations on small celestial bodies like Earth, scientists used the LARES-2 (Laser Relativity Satellite 2) apparatus developed by the Italian Space Agency. With a diameter of about 40 centimeters and a weight of 295 kilograms, this device consists of a solid sphere made of a nickel-chromium alloy. It carries no engines, solar panels, or onboard electronics.

The entire surface of the apparatus is covered with 303 corner-cube retroreflectors, and its heavy and dense structure minimizes the influence of any non-meteorological forces in medium Earth orbit. From July 2022 to June 2025, ground stations irradiated the satellite with lasers and recorded the returned light signals. As a result, scientists gathered a database of 200,000 observations with a precision of 1 millimeter.

Data cleaning and fundamental results

Due to the unevenness of Earth's gravity, the planet is slightly flattened at the poles, which generates Newtonian forces and masks the relativity signal. To filter out this classical gravity, researchers combined LARES-2 data with readings from the LAGEOS apparatus launched by NASA in 1976. The orbital planes of both satellites differed by an angle of 180.01°, ensuring the mutual mathematical cancellation of unwanted forces.

An additional obstacle was caused by ocean and land tides driven by the Moon and the Sun. This problem was solved over time: tidal effects are mutually compensated in a 1,050-day precession cycle. All interferences were cleared using NASA's GEODYN software from the Goddard Space Flight Center.

After the cleaning process, physicists recorded that the Earth's rotation shifts the satellite orbit by 61.3 millarcseconds per year. The obtained value matched Einstein's theory predictions perfectly. The authors note that this result not only confirms general relativity but also strictly constrains alternative models such as Chern-Simons gravity, which attempts to unite it with quantum mechanics.