Eötvös experiment

The Eötvös experiment is a program conducted by Loránd Eötvös and colleagues in Budapest experiment to gravity. The experimenters have checked whether the body would fall from different materials such as brass, glass, cork wood and Antimonitkristalle in divergent directions. There was no difference in the direction of fall for different objects to be measured. Within the framework of Newtonian gravity, the experiment is considered as a check of the relation between gravitational mass and inertial mass of the measured objects in question. This assessment is based on the idea that the body could respond with a different ratio of inertial and gravitational mass differently to the gravitational field of the earth. According to Newton's theory, the weight of a body on the earth's surface by two fundamentally different forces is determined - the gravitational force on the one hand and a resulting from the self-rotation of the earth inertial force, the centrifugal force, on the other hand.

Loránd Eötvös conducted this experiment first in 1889 by and published his results in 1890. Together with Pekár and Fekete he refined the measurements in the years 1906 until 1909.

At the location at which the experiment was performed, both forces are not in the same direction. Therefore, different types of bodies that react differently to the two force components of gravity, easily fall into divergent directions. It would also be conceivable that they fall at different rates. This possibility has not been studied in the context of the Eötvös experiment; this was done already by Galileo Galilei and Isaac Newton, and after that by many other experimenters.

For the experiment, a long torsion pendulum is used:

• Two body at the lower end of the pendulum experienced by the acting centrifugal force due to the Earth's rotation, a deflection in the direction of the earth's equator; the deflection force is proportional to the inertial mass.
• The deflection counteracts the gravitational force; this is proportional to the gravitational mass.
• The measured deflection is consistent with the calculated when inertial mass and gravitational mass are the same values ​​used in the calculations.

The fact that the examined body remain at rest in the laboratory system, no dynamic variables, but only the deflection angle were measured. It could be shown with a precision of 1:108, that the ratio of gravitational and inertial mass is the same for all investigated body. This accuracy was later improved by more than three orders of magnitude.

This first purely empirically established equivalence suggests a close relationship between gravitational and inertial forces. Albert Einstein made ​​the equivalence principle as the basis of his general theory of relativity.

A modern version of the Eötvös experiment is the molybdenum -disc experiment ( EOET -Wash experiment).