Complex sentence: Fenn Tower formerly housed what was at one time the longest Foucault pendulum in the world; however, the pendulum has been inoperational since 1980 and was removed during the residence hall renovation in 2006.
Split into simpler sentences: Fenn Tower formerly housed what was at one time the longest Foucault pendulum in the world. However, because the pendulum had been inoperative since 1980 it was removed during the residence hall renovation in 2006.