Bilkent News Picture Challenge
I Know Where You've Been This Week

BY TULYA KAVAKLIOĞLU (MBG/IV)

Hello everyone! The weather is getting better, so why don't you get out and have a nice little walk on campus. Enjoy the breeze running through your hair, the sun above. Who knows, maybe you will come across this thing in the picture here? If you do, send your answer and maybe win a coffee or a lunch.

Last week I went behind the Faculty of Science building. I think many of you use those stairs starting from the parking lot, where you can see Cafe Speed from top. The stairs end at the back of SA building. Last week's picture was taken exactly at that place, and it was a picture of the stairs inside the building rolling around Foucault’s Pendulum.

This pendulum was designed by Jean Bertrand Leon Foucault in 1851 and hung in the Pantheon in Paris. Foucault proved for the first time without an astronomical observation that the Earth rotates on an axis. This pendulum is actually a long wire with a weight at its end. Once the pendulum starts to swing, at some point it starts to oscillate, subtly changing direction constantly. Since no other force is applied to the pendulum to alter its path, Foucault deduced that it is the movement of the Earth that affects it.

The Foucault Pendulum in the SA building works with the help of an electromagnet. Of course after a certain time, because of gravity, air friction and so on, it loses energy and starts to slow down. When its speed reaches a certain level, the electromagnet located on the floor turns itself on, pushes the pendulum a little bit and turns itself off again. So the pendulum oscillates all the time, night and day.