By Becky Ferreira Feb 26, 2013
The Pitch Drop Experiment
"Pitch" is a term for tar derivatives (pictured here), and it's the material used in an experiment that has been ongoing for almost a century! Physicist Thomas Parnell wanted to demonstrate the extraordinary properties of ordinary materials, and used pitch to show that solids can act as fluids over long periods of time. The pitch was put into a funnel, and over the course of many decades, it has dripped into its container 8 times (you can watch the ninth drop forming here). Materials that may appear static in our timeframe tell a different story over longer time periods.