What can be considered one of the longest running, single experiments finally has some closure after 69 years. The exiting moment that brought it to a close? A drop of “pitch-tar” finally fell — and someone saw it.
That’s right, the experiment at Trinity College Dublin was set up in 1944 to show the high viscosity of pitch/bituman/asphalt (the substance goes by many names), according to the college’s website.
The substance might appear solid at room temperature, but it is actually moving very, very slowly. According to the institution, it didn’t take nearly seven decades for a tar droplet to form and drip from the funnel, but no one had ever witnessed it happen since the experiment was running. A drop happens about once a every 10 years.
This spring when it looked like a drop was getting close to falling, Professor Shane Bergin wasn’t going to let anyone miss it, putting a webcam on it. Last week on July 11, the drop finally fell.
“People love this experiment because it gets to the heart of what good science is all about – curiosity,” Bergin said in a statement. Over these past few months, there has been constant chat about when the drip would drop. I watched the time lapse video of the pitch drop falling over and over again. I was amazed. This was the first time this phenomenon was ever witnessed!”
Here’s a time-lapsed video of the momentous occasion:
Having video evidence of the droplet and knowing how long it took to fall since the last drop, physicists estimate the substance is 2 million times the viscosity of honey.
The University of Queensland holds the Guinness World Record for longest experiment for a similar set up that has been running since 1927, but no one has yet witnessed it.