https://freerepublic.com/tag/populaymechanics/ en-us Sun, 7 Jun 2026 00:16:00 GMT Focus Forum 15 https://freerepublic.com/focus/f-chat/4382657/posts Water has mass, and mass has leverage. Move enough groundwater from aquifers onto farms, into cities, and eventually into the ocean, and Earth’s spin changes by a measurable amount. The shift is tiny on a planetary scale, but the number still grabs you: between 1993 and 2010, researchers estimated that groundwater depletion nudged Earth’s rotational pole by about 31.5 inches. The figure comes from a 2023 study in Geophysical Research Letters, which estimated that humans depleted about 2,150 gigatons of groundwater between 1993 and 2010. When researchers added that water movement to their polar-motion model, the model lined up much... Popular Mechanics https://freerepublic.com/focus/f-chat/4382657/posts#comment Sun, 7 Jun 2026 00:16:00 GMT