80-year experiment put in the hands of Ireland’s young scientists

Posted on: 27 November 2024

The National Pitch Tar Drop Event, run by Trinity's School of Physics in collaboration with the AMBER Research Ireland Centre and the Institute of Physics. will see a School in every county participate in Citizen Science.

A National Pitch Tar Drop event launches today, putting an 80-year experiment that continues to captivate people across the globe in the hands of Ireland’s young scientists.

The Pitch Tar Drop demonstration in Trinity’s School of Physics began in October 1944, and it has been running ever since. It is currently one of only three such experiments in the world, with the team last capturing footage of the pitch tar drop in Trinity in 2013.

While appearing solid at room temperature, the pitch tar flows very slowly with a drop falling from the end of the funnel approximately once each decade. The most recent drop fell unobserved in 2024.

It will be another decade before the demonstration will drip again, so Trinity’s School of Physics – as part of their 2024 Tercentenary Celebrations and in association with the AMBER Research Ireland Centre and the Institute of Physics – are hosting an All-Island Pitch Tar Drop Event.

Schools across Ireland will participate in the experiment in which they have been provided with a kit that uses a specially developed pitch tar, which has a lower viscosity than the Trinity demonstration, so we won’t have to wait 10 years.

In this national experiment students will see seemingly solid materials flow, be able to measure the formation of the drop, calculate the viscosity and perhaps even capture that special moment when the drop falls.

Hosted by Louise Bradley, Professor in Trinity’s School of Physics, the launch takes place today. She will be joined by Prof. Stefan Hutzler, who in 2013 alongside Dr Shane Bergin captured a drop falling in Trinity, when they became the first to record this rare moment.

The time-lapse video attracted global media attention at the time with Discover Magazine naming the Trinity Pitch Drop in their top 100 science stories of 2013 and a feature article in Nature News the third-most read piece on their website that year.

In recognition of its global fame the pitch tar demonstration had been on display in the Eavan Boland Library since 2014 but returned to its permanent home in the School of Physics in time for the tercentenary.

Professor Louise Bradley said: “This experiment is a fantastic example of citizen science and making STEM tangible and accessible. This experiment’s longevity and being only one of three in the world also gives participants the opportunity to be part of history.”

This National Experiment will culminate in a Shared Learning Day hosted by Trinity’s School of Physics and AMBER on Thursday 27th March 2025. Teachers from participating schools will bring two students from their school who will have contributed to the preparation of a scientific poster demonstrating the observations and outcomes of their own pitch tar experiments in the schools.

Media Contact:

Thomas Deane | Media Relations | deaneth@tcd.ie | +353 1 896 4685