The Eöt-Wash Group:
Laboratory Tests of Gravitational and sub-Gravitational Physics
Experimental Motivation
At the heart of General Relativity lies the equivalence principle. In its simplest Newtonian form, it simply states that inertial mass and gravitational mass are the same thing, that is, gravity (as we know it) is the only fundamental force that couples exactly to mass, rather than to some kind of charge. The latter statement forms the basis of many of the experiments our group performs.
Many modern quantum theories of gravity predict violations of the equivalence principle, usually by Yukawa forces that couple differently to different chemical elements. Predictions for the range and strength of such violations have varied a great deal, and so we have performed torsion balance tests of the equivalence principle designed to be sensitive to ranges as small as a centimeter.
Recently new predictions about possible new behavior of gravity at short length scales have appeared. Instead of violating the equivalence principle, these theories predict violations of the gravitational inverse-square law. These suggest that gravity, and only gravity, penetrates extra, compact dimensions. These interesting hypotheses have been offered as solutions to the hierarchy problem (gravity is extremely weak when compared with any other force), and are the basis for our latest, short-range experiment.
You're encouraged to peruse our front page, results, experiments, and, of course, our publications to come to a greater understanding of why we're excited about our work!
© 1987-2008 Eöt-Wash Group. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation, DOE or NASA. Trouble? Comments? Contact cah49#at#u.washington.edu