A SIMPLE EXPERIMENTAL DEMONSTRATION OF THE PRINCIPLE OF EQUIVALENCE

According to the principle of equivalence, local experiments, in all f reely falling frames of reference, are independent of the gravitationa l held surrounding this frame. A simple experiment, in which Einstein' s freely falling elevator is replaced by a pendulum system sliding dow n an inclined plane, serves as a demonstration for this principle. The pendulum experiences a force orthogonal to the inclined plane. With a n eddy current damping mechanism, the oscillation of the pendulum can be damped, and the pendulum will move into its equilibrium position or thogonal to the inclined plane shortly after being released from rest. (C) 1997 American Association of Physics Teachers.