The World's Longest-Running Lab Experiment Is Almost 100 Years Old

The Pitch Drop Experiment, initiated in 1927 by physicist Thomas Parnell at the University of Queensland, is the world's longest-running lab experiment. It involves observing the flow of pitch, a highly viscous fluid, through a funnel. The first droplet took eight years to fall, and since then, only nine drops have occurred, with the last one in 2014. The experiment is now live-streamed, but no one has ever witnessed a droplet fall directly.