A Test of Newton's Inverse-Square Law in the Greenland Ice Cap.
01 January 1989
An Airy-type geophysical experiment was conducted in a 2-km- deep hole in the Greenland ice cap at depth between 213 m and 1673 m to test for possible violations of Newton's inverse- square law. An anomalous gravity gradient was observed. We cannot unambiguously attribute it to a breakdown of Newtonian gravity because we have shown that it might be due to unexpected geological features in the rock below the ice.