The custodian of the world’s longest running laboratory experiment, Professor John Mainstone, died last week after suffering a stroke. He was 78.



The former Head of the Department of Physics was the guardian of the world-famous pitch drop experiment.

The University of Queensland’s Head of the School of Mathematics and Physics, Professor Halina Rubinsztein-Dunlop, said UQ had sent its condolences to Professor Mainstone’s family.

"Professor Mainstone’s dedication to the long-running experiment well past his official retirement ensured that media, researchers and undergraduate students had easy access to relevant information and an understanding of the important science behind it,” she said.

“John will be greatly missed around the halls of the Parnell Building at UQ where he maintained an office and a close connection with UQ until his death last week.”

The Pitch Drop Experiment was established in 1927 by Professor Thomas Parnell to demonstrate the fluidity and high viscosity of pitch, a derivative of tar once used to waterproof boats.

At room temperature pitch feels solid - even brittle - and can easily be shattered with a blow from a hammer but, surprisingly, it acts like a fluid.

Three years after the commencement of the experiment, the glass funnel holding the pitch was cut to allow the pitch to “flow”.

Only eight drops have fallen in the 83 years since the pitch began dripping, and no-one has ever seen one fall.

Professor Mainstone had been custodian of the Pitch Drop Experiment for 52 years.

“John’s death is particularly sad as in his time as the custodian of the experiment, he did not see a single drop fall,” said Professor Rubinsztein-Dunlop.

The experiment is now under constant surveillance, with three webcams trained on it to capture the ninth drop’s fall on camera.

The live feed of the experiment can be viewed at www.smp.uq.edu.au/content/pitch-drop-experiment.

The Pitch Drop Experiment has been seen by many as an enduring example of UQ’s dedication to the pursuit of scientific knowledge.

Media: Julie Baglot, UQ Faculty of Science; 0411 162 577; j.baglot@uq.edu.au; Chris Shannon, SMP School Manager, 0403 349 320 or chris.shannon@uq.edu.au

Professor John Mainstone, OAM (1935-2013)

• Joined the University of Queensland as a Lecturer in Physics in 1961.

• Became Senior Lecturer in 1966 and was promoted to Associate Professor in 1973.

• Head of Department of Physics at UQ from 1989-1996.

• Research interests were in in the area of Physics of Atmosphere and Magnetosphere.

• Awarded Order of Australia: OAM in the General Division: Queen’s Birthday Honours List in 2004.

• Custodian of the World’s Longest Running Laboratory Experiment, The Pitch Drop Experiment, for 52 years.