Abstract

About 22 years ago, the physics world was briefly rocked by claims of evidence for a new “5 th force”, based on reanalysis of data from an early 20 th century experiment. Baron Roland von Eötvös, a Hungarian nobleman, had performed extensive measurements of the correlation between inertial mass and gravitational mass and published them in 1922. The lead article in the January 6, 1986 issue of Physical Review Letters had the unassuming title: "A Reanalysis of the Eötvös Experiment" by Ephriam Fischbach, et al. Two days later the New York Times ran an article with the headline: "Hints of Fifth Force in Universe Challenge Galileo's Findings" describing the possible implications of Fischbach's work.