Laser-aligned pendulum

Thanks to some undergraduate slave labor from the University of Buffalo, the Foucault Pendulum at the Buffalo Museum of Science is back in full-time service.

[John Cerne, assistant professor of physics] said the new-and-improved circuit at the Buffalo Museum of Science eliminates the loss of power that takes place as the pendulum oscillates by using an electromagnet to tug the weight or "bob" and restore momentum. The magnet is triggered in short bursts based on information it receives from two laser sensors. The original circuit at the museum used a less-efficient system that controlled the magnet with broken beams of light, rather than lasers.

Before the repair, the pendulum never ran for more than eight hours at a time. Now, as long as there's power, it will run indefinitely.

Unfortunately I couldn't find any good pictures of the museum exhibit but UofB installed their own pendulum in Fronczak Hall and have published a number of images online, shown through the link below.