Slowest liquid in the world?

While a lot has changed in the last 77 years, some things have remained stable. The pitch drop experiment in Trinity College, Dublin is one such example. It was started in 1944 by a colleague of Ernest Walton (Nobel Prize winner) to prove the high viscosity of pitch. At room temperature, pitch appears solid but it’s actually fluid in nature. It’s just that one drop takes 10 years to form.

To understand viscosity, take a drop of water in a spoon and allow it to fall. It does so very quickly because water isn’t highly viscous. Now, take a drop of honey in a spoon and allow it to fall. It takes a longer time as the honey will first form a thread before detaching. In the case of pitch, this simple process takes ten years.

In 2013, Stefan Hutzler (Associate Professor of Physics in Trinity) and his colleague Shane Bergin noticed a drop forming. They decided to create a time lapse video recording the drop. Once the video was made, it started getting recognition from media outlets like RTE News, Huffington Post, Wall Street Journal, New Scientist and National Geographic.

Despite its success, Hutzler is embarrassed about being the face of the experiment. “I mean, we didn’t really do much, the stuff was there. Shane (Bergin) and I just decided to put a camera on it, a very poor resolution camera and all of a sudden you get RTE interviewing you.

You do good scientific work and you get no publicity, and then this thing comes along and all of a sudden you make it on the main evening news. I thought that was bizarre,” he said in an interview with The University Times.

You can watch the first recorded instance of a pitch drop here.