World’s Longest Experiment, Still Running Will Go For Another 100 Years

The Pitch Drop Experiment, started in 1927 by Thomas Parnell at the University of Queensland, is the world’s longest-running scientific experiment. It demonstrates the incredibly slow flow of pitch, a substance 100 billion times more viscous than water. Despite its glacial pace, only nine drops have fallen in nearly a century. Scientists predict it could continue for another 100 years.