Grand Valley State University Bifilar Pendulum

Today I gave a presentation at the 2014 Biennial Conference on Chemistry Education (BCCE) at Grand Valley State University.  Beforehand, I found this pendulum nearby which traces patterns in the sand below it. Though it is an excellent demonstration of pendulum motion, it is also known for its five minutes of infamy, as GVSU students tried to ride the ball in satire of the Miley Cyrus wrecking ball video.  Apparently students have done this before, but some of them were unclothed and someone almost got injured, so the ball got taken down while the installation was redesigned.  News about this can be found here: http://www.businessinsider.com/grand-valley-state-university-reinstalled-the-miley-cyrus-wrecking-ball-sculpture-2013-11