Pitch shatters like glass when you hit it with a hammer — yet left alone it flows. A single drop takes about a decade to fall, and for 97 years no one managed to catch one in the act.
Start here: how a lump of pitch sealed in a funnel in 1927 became the world's slowest science experiment, dripping on a timescale of human generations.
Thomas Parnell started it to prove pitch is a fluid; it is roughly 100 billion times more viscous than water. He died in 1948, long before the third drop fell.
Guinness World Records on the Queensland funnel — and the estimate that enough pitch remains to keep it dripping for another hundred years.
The custodian who watched over the drop for 52 years missed every single fall — once by stepping out for a cup of tea, once when the webcam crashed at the decisive moment.
In 2013 a rival experiment at Trinity College Dublin — running since 1944 — finally filmed a drop falling. The first time in history anyone witnessed it live.
A tidy recap of the whole saga: the physics of a solid that flows, the decades of near-misses, and why anyone bothers watching a funnel for a century.