World record in the underground laboratory of Membach: A sphere of mass 4 grams has been levitating for 8081 days

On Monday 18th of September 2017, the superconducting gravimeter of the Seismology-Gravimetry service installed at the Royal Observatory of Belgium’s facility in Membach (close to Eupen, eastern Belgium), broke two records: firstly, the gravimeter has been measuring gravitational variations for the longest recorded period at a single location, and secondly, recorded the longest period that an artifact has been levitating [...]