General Relativity - Eotvos Experiment
The Eotvos experiment is a key test of the Equivalence Principle,which is a foundation of Einstein’s General Theory of Relativity. It was conducted by Baron Lorand Eotvos, Hungarian physicist,in the late 19th and early 20th centuries. The objective of this experiment is to test whether inertial mass and gravitational mass are equivalent - that’s, whether different materials fall at the same rate in a gravitational field,regardless of their composition. He looked for differences in the gravitational acceleration acting on different materials,but no measurable difference was observed in the acceleration of the test masses. Eotvos results confirmed that gravitational mass is proportional to inertial mass to very high precision,of the order of 1 part in 10^9 in later improvements.