In 1927, Professor Thomas Parnell of the University of Queensland in Australia set out to teach his students a lesson, and that lesson is still going on today and has at least another 100 years to go.
The physics professor wanted to demonstrate to his pupils that solid material could have viscous properties, so he used tar pitch, a derivative of coal once used to waterproof boats, in an experiment to prove his point.
At room temperature, pitch appears to be solid and can even shatter if hit with a hammer, but despite its look and feel, pitch can also flow at room temperature--just really, really slowly.
To conduct the Pitch Drop Experiment, Parnell melted some pitch into a glass funnel with a sealed stem and allowed it to settle for three years. In 1930, the funnel was unsealed, clearing the way for the pitch to flow freely, but it sure did take its sweet time. … Read more