Discover the Century-Long Pitch Drop Experiment: The World’s Longest-Running Scientific Study

The Pitch Drop Experiment, held by the University of Queensland, Australia, is the longest-running scientific experiment. It started in 1927 under physicist Thomas Parnell. The goal is to measure the flow and high viscosity of pitch, a thick fluid derived from tar.

What Is the Experiment?

Parnell heated pitch and poured it into a glass funnel. After three years, he cut the funnel’s stem to observe the flow. The experiment was a demonstration, and it is displayed in a cabinet. Its rate of flow changes with temperature.

After Parnell, Professor John Mainstone took care of the experiment for 52 years. Since it began, the pitch has dripped very slowly. The first drop took eight years to fall, and more than 40 years passed before five more drops fell. So far, nine drops have fallen, and another one is expected this decade. However, no one has witnessed a drop fall due to delays.

Findings of the Experiment

Pitch seems solid and can shatter with a hammer, but it has a viscosity 100 billion times greater than water. There is enough pitch in the funnel for the experiment to continue for another 100 years.

In 2005, the Ig Nobel Prize was awarded to Maidstone and Parnell. This prize celebrates unusual scientific achievements that make people laugh and think.