15 Gravity vs. Gravitation (media.communities.win) posted 2 years ago by PepesCovfefe 2 years ago by PepesCovfefe +15 / -0 26 comments download share 26 comments share download save hide report block hide replies
Gravimeters, they use them in geology and mining. It measures variations in gravity. You can tell if you are on top of a cave system, or over heavier deposits.