Pitch drop

A drop in the river of time

Some things in science are worth waiting for.

Sometime towards the end of this year, one of the rarest events in science is expected to occur. In a display case in the lobby of the physics department at the University of Queensland in Brisbane, Australia, a small drop of black tar distillate known as pitch will detach itself from the stem of a funnel and fall into a waiting beaker below. It will be the first time a drop has fallen in 13 years, and only the ninth such drop since the experiment was set up 86 years ago.

Thomas Parnell, the university’s first professor of physics, set up the pitch drop experiment to show his students that pitch, which is brittle enough to shatter if hit with a hammer, can flow like a liquid if left to its own devices long enough. Over the course of almost a century, the experiment has survived the relocation of the university campus, extensive renovations to the physics building where it is housed and innumerable changes in university administration and staff. But it serenely carries on, despite the turmoil of the world all around it. Read more in Materials Today.

Pitch-drop custodian dies without witnessing a drop fall

Photo courtesy of University of Queensland.

Photo courtesy of University of Queensland.

John Mainstone, who for 52 years tended to one of the world’s longest-running laboratory experiments but never saw it bear fruit with his own eyes, died on 23 August after suffering a stroke. He was 78.

Mainstone had been looking after the pitch drop experiment at the University of Queensland in Brisbane, Australia since he arrived at the university as a physics professor in 1961. The experiment, set up in 1927 by the university’s first head of the physics department, Thomas Parnell, consists of a sample of tar pitch slowly running through a funnel (see ‘Long-term research: Slow science‘). Read more in Nature.

Slow science

The world’s longest-running experiments remind us that science is a marathon, not a sprint.

Although science is a long-term pursuit, research is often practised over short timescales: a discrete experiment or a self-contained project constrained by the length of a funding cycle. But some investigations cannot be rushed. To study human lifespans or the roiling of Earth’s crust and the Sun’s surface, for instance, requires decades and even centuries.

Here, Nature takes a look at five of science’s longest-running projects, some of which have been amassing data continuously for centuries. Read more in Nature.