3246 20170918145011.0 Van Camp, Michel World record in the underground laboratory of Membach: A sphere of mass 4 grams has been levitating for 8081 days 2017 2017-09-18 NO Membach superconducting gravimeter world record michel.vancamp@observatoire.be http://www.astro.oma.be/fr/record-mondial-dans-le-laboratoire-souterrain-de-membach/ http://www.astro.oma.be/nl/wereldrecord-in-het-ondergronds-laboratorium-van-membach/ http://www.astro.oma.be/en/world-record-in-the-underground-laboratory-of-membach/ PRESSREL