Tar pitch is funny stuff. If you hit it hard, it’ll shatter — but give it enough time, and it’ll flow like water. How much time? Well, how about the rate of one dop per decade, and that famed drop has finally been captured on film.
The best known Pitch Drop Experiment began in 1927 and has been running ever since, but a similar eperiment was set up in Trinity College, Dublin in October 1944, and recently when the pitch dropped on that experiment, it was captured on film or video for the first time.
Due to the extreme viscosity of tar pitch (something like 230 billion times that of water), the pitch drops about once a decade, and only takes a few seconds to happen, making it easy to miss.
In fact, the original experiment in Australia has had a number of famous misses in its rare drops. Professor John Mainstone in Queensland once stepped out to get a cup of tea, leaving his long term vigil of the drop, and in the 15 minutes he was away the pitch dropped. In 2000, video equipment malfunctioned, failing to record the drop.
Thankfully, the advent of webcam technology has simplified the recording process, and finally, for the very first time, the pitch drop has been recorded.