“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.
This curiosity of an experiment demonstrates that tar, or pitch, is a material that flows – albeit it with an incredibly high viscosity. Whilst pitch has been dropping from the funnel since 1944, nobody has ever witnessed a drop fall – they happen it happens roughly only once in a decade!
In May of this year, with the latest drop about to fall, Prof. Shane Bergin broadcast the experiment via the web. On July 11th, the drop dripped.
Tracking the evolution of the drop, Profs. Weaire & and Hutzler, and Mr. David Whyte calculated the viscosity of the pitch to be 2×107 Pa s – approximately 2 million times the viscosity of honey.”
From the Trinity College of Dublin website HERE
“A similar, better-known and older experiment in Australia missed filming its latest drop in 2000 because the camera was offline at the time.”
From Nature News HERE
The experiment is explained nicely in THIS Radiolab clip.
Or check out the video below!