A team of scientists have finally filmed a sight they have been waiting to see for decades: a drop of extremely slow-moving pitch break off and fall.
The team running the pitch-drop project at Trinity College in Dublin witnessed the drop fall at roughly 5pm on July 11, according to Nature News.
It may not seem like a hugely momentous event, but moments like these only come around once a decade or so, and the drop has never been filmed before. Paying close attention to how this slower-than-molasses experiment gives scientists an extraordinary glimpse into the physical properties of an ordinary substance.
“We were all so excited,” project leader Shane Bergin told Nature News. “It’s been such a great talking point, with colleagues eager to investigate the mechanics of the break, and the viscosity of the pitch.”
Pitch, also known as asphalt or bitumen, moves so slowly at room temperature that it appears to be a solid. Watching the drop allowed the team to estimate the viscosity of the pitch: It flows about 20 million times slower than honey and more than 2 billion times slower than water.
They think that the funnel and pitch was set up in 1944 by Nobel laureate Ernest Walton who was a professor at the school. They think he wanted to use the experiment as an educational tool.
When first set up it took three years for the blob of pitch to begin flowing out of the funnel, and then another seven to 10 to form a drop. The set up lay neglected for years, until scientists literally blew the dust off the pitch and began watching it again.
The flowing pitch is one of the world’s longest-running scientific experiments. Last April, they set up a web cam so people around the world could watch the drop finally break off and fall.
While it has taken years to flow out of the funnel, it only takes a tenth of a second for the drop to dislocate and fall. Seeing it happen is so rare that in the 83 years that an even older pitch experiment has been running at the University of Queensland in Brisbane, Australia, no one has witness any of the nine drops have fallen.
Watch the Trinity College drop fall, the first time this historic event has ever been captured on camera:
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