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.