According to fundamental physics, the properties of mass—weight, inertia, and gravitation—always remain the same relative to each other. If this is not true, Einstein’s theory of relativity would be debunked.
Now, however, quantum theory asserts that there should be a violation. The inconsistency between Einstein’s gravitational theory and modern quantum theory begs for more tests. Researchers from the Center of Applied Space Technology and Microgravity (ZARM) at the University of Bremen, in collaboration with the Institute of Geodesy (IfE) at Leibniz University Hannover, succeeded in proving with 100x greater accuracy that passive gravitational mass and active gravitational mass are always equivalent—regardless of the composition of the respective masses. The findings were published in the scientific journal “Physical Review Letters.”
Inertial mass resists acceleration, passive gravitational mass reacts with gravity and results in our weight on Earth, and active gravitational mass refers to the force of gravitation exerted by an object. The equivalence of the properties is fundamental to general relativity. The equivalence of inertial and passive gravitational mass and the equivalence of passive and active gravitational mass are being tested with greater precision.
If we assume that passive and active gravitational mass is not equal, objects made of different materials with different centers of mass will accelerate themselves. The Moon consists of an aluminum shell and iron core, with centers of mass offset against each other, so it should accelerate. The change in speed can be measured via “Lunar Laser Ranging,” whereby the round trip travel times of laser beams are recorded. The research team analyzed data collected over 50 years, from 1970 to 2022, investigating mass difference effects and finding none. This means the passive and active gravitational masses are equal to approximately 14 decimal places—100x hundred more accurate than the best previous study, dating back to 1986.