The Pitch Drop Experiment: A 90-Year-Old Demonstration of Viscosity

TLDR The Pitch Drop experiment, created in 1927, is the world's longest running scientific experiment, demonstrating the concept of viscosity. After 90 years, only nine drops of pitch have fallen, with the next drop expected to occur later this decade.

Timestamped Summary

00:00 The Pitch Drop experiment, the world's longest continually running scientific experiment, was created in 1927 to demonstrate the concept of viscosity and is still ongoing 90 years later.
01:31 The concept of viscosity refers to a fluid's resistance to deformation at a given rate, with water having a low viscosity and substances like peanut butter and toothpaste having very high viscosities.
02:50 In 1927, Professor Thomas Parnell conducted an experiment to demonstrate that certain substances that appear solid are actually highly viscous fluids, using pitch as an example.
04:10 In 90 years, exactly nine drops of pitch have fallen from the funnel, with the time between drops increasing after the seventh drop due to the installation of air conditioning, and the next drop is expected to occur sometime later this decade.
05:36 No one has ever seen any of the nine drops take place, but the experiment has been awarded the Ig Nobel Prize in Physics and holds the record for the world's longest running laboratory experiment.
06:52 In April 2013, a drop was forming in the pitch drop experiment and was captured on camera in July of that year, revealing that pitch is 30 billion times more viscous than water.
08:10 The pitch drop experiment at the University of Queensland is not the only one of its kind, as there is another experiment at Aberystwyth University in Wales that dates back to 1913 and is estimated to take 1,300 years for the first drop to fall.
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