10. "Faith in Physics" Pendulum

In this dramatic demonstration a massive weight is suspended by a wire from the ceiling of the lecture hall. The demonstrator stands braced against the wall, draws the mass to his nose, and releases it. If conservation of the energy holds, on the return swing the mass will stop just millimeters in front of his nose. But if conservation of energy fails,...!

The lengths of the pendulums in the corresponding lecture halls are as follows:

PAB 1425 4.66 m
KNSY PV 1220B 4.67 m