Pitch Drop Scientist Remembered For Record-Setting Experiment

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Science professor John Mainstone died over the weekend at age 78. The Australian was overseer of what is said to be the world's longest running physics experiment. It was a flask with "pitch" or tar set up to allow it to "drip" — but very slowly. In 87 years only a handful of drops have fallen. The test was to prove that pitch was actually a liquid not a solid, although it shattered like a solid.


We note now the passing of man who had patience, remarkable patience. John Mainstone died over the weekend. He was 78. For more than half a century, the Australian physics professor at the University of Queensland oversaw what Guinness World Records calls the world's longest running science experiment. His subject: pitch, as in tar.


Mainstone spoke in March to the Australian Broadcasting Company about the experiment that was begun in 1927 by Professor Thomas Parnell to prove the theory that an apparent solid could drip like a liquid.


JOHN MAINSTONE: He poured some pitch, which he'd heated up into the top of the funnel. The bottom of the stem had been sealed. We waited for it to settle over a period of about three years. And then, I guess, with slightly bated breath waited to see whether it would do what he thought it would do - hoped it would do probably is a better way of expressing it - namely produce drops.

SIEGEL: Got that pitch into a funnel. Once it's hardened, will it still drip? Well, since 1927, it has dripped just eight times. There's a little puddle beneath to prove it.


MAINSTONE: It's got a mind of its own. And in the blink of an eye, it can drop because ultimately it starts falling under gravity.

BLOCK: The last time a drop fell was back in November 2000. Mainstone's team had set up webcams to capture the moment, but they were shut off at the time. When he spoke this past spring, Mainstone said he thought it was time for another drop.


MAINSTONE: I would be surprised if it lasts more than until the end of this year.

SIEGEL: Scientist John Mainstone, who died over the weekend at age 78. After more than 50 years of studying tar in that funnel, we're sorry to report, he never did see it drip.

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