The Trinity Pitch Drop Demonstration
This time lapse video shows the moment the drop dripped on July 11th, 2013. The first time this rare event was capture on video. Tracking the evolution of the drop, Profs. Weaire & and Hutzler, and Mr. David Whyte calculated the viscosity of the Trinity pitch to be 2x107 Pa/s - approximately 2 million times the viscosity of honey, or 20 billion times the viscosity of water. The scientific articles [ The Pitch Drop Experiment & Physics World Article ] provide more information on how the viscosity can be calculated.
When you read this article from The Conversation you can start to understand how rare it is to see a drop drip!
Explainer: the pitch drop experiment (theconversation.com)
Further Information on the University of Queensland Pitch Drop Experiment can be found at
Pitch Drop experiment - School of Mathematics and Physics - University of Queensland (uq.edu.au)
Pitch-Tar Drop, School of Physics, Trinity College Dublin
Begun in October 1944, the Tar Drop experiment, at Trinity College Dublin's School of Physics, is one of the world's oldest continuously running experiments.