Tamarack Mine Experiments: Plumb-bobbing the Earth
Around the turn of the century experiments were performed in Calumet Michigan where they suspended two plumb-bobs down adjacent mine shafts. Since we live on a convex spheroid(planet earth) where the center of gravity is about 4000 miles beneath our feet, we’d expect the two plumb-bobs to be closer together at the bottom than they are at the top. (tl/dr that didn’t happen) It took half and hour to drop the 50 pound plumb-bobs over 3/4 of a mile down the two mine shafts. They waited a full day for the two lines to remain still, even using engine oil at the bottom to submerge them in, quickening the settling process. Once they were fully settled, physical measurements were taken between the horizontal distances at the top and at the bottom. With a center of gravity roughly 4000 miles below (the center of earth),…
