Longest-running laboratory experiment
The Pitch Drop Experiment
Australia (Toowoomba)

The Pitch Drop Experiment has been running since 1927 at the University of Queensland, Australia. It consists of black pitch contained in a glass funnel, with the entire apparatus enclosed in a container. It demonstrates that pitch is actually an extremely viscous liquid. Once the stem of the funnel was cut, the pitch slowly began to drip. In late 2000, the 8th drop fell. From this experiment it has been possible to demonstrate that the viscosity of pitch is about 100 billion times that of water. There is enough pitch still in the funnel for this famous experiment to run for another hundred years.

The experiment was initiated by the University of Queensland's first physics professor, Thomas Parnell.