Pitch Experiment Encounters Ninth Drip In 87 Years

Since 1927 scientists at the University of Queensland in Brisbane, Australia, have hosted the worlds longest experiment. It all started to prove that materials we think to be solid are in fact highly viscous fluids. And now, for the first time in the experiment’s history, a drop of pitch has been observed.

This isn’t the first time the pitch has dripped a drop. It’s happened on eight other occasions – but none of those times have been witnessed by eye or camera. It’s a slow process that used to take 9 years each drip. The 8th and 9th drops of pitch have taken 4 years longer (13 years total) because gases in the pitch escape and the weight of the pitch in the funnel decreases. So far the experiment has been going on for 87 years, making it the longest lasting experiment in the world. The funnel of pitch is kept on campus at all times unless on exhibition.

Pitch was believed to be a solid. It’s the stuff used to make boats waterproof and it can be shattered into pieces by a hammer. The pitch experiment began by heating up some pitch to get it into a container. After that they let it settle for a bit – three years – and opened a seal at the bottom of the funnel. And it’s been slowly making history ever since. Even though the pitch is painfully slow moving and a bore to watch without time-lapse, when developments happen they happen fast. The ninth pitch drop was announced the moment it touched against the glob of the eight drop. The moment was captured on film and becomes the first documented pitch drip.

The pitch’s former custodian of the experiment, John Mainstone, missed observing the drops fall on three occasions – by a day in 1977, by only five minutes in 1988 when it was on display at the World Expo in Brisbane, and in 2000 when a webcam that was recording it missed the crucial moment when the drop fell during a 20-minute power outage. Unfortunately he was unable to witness the illusive and long-anticipated pitch drip in his lifetime.

The pitch is under constant video surveillance to capture the long-lasting flow that confirms the University’s original hypothesis. After seeing the time-lapse results it can’t be denied that pitch is in fact a liquid. The remaining volume of pitch will continue to challenge our perception of reality until it’s last drop is dripped.