An example of the Ford viscosity cup as used to measure the viscosity of paints and other fluids that flow readily (Photo: Dariusa.Biegacz via Wikipedia)
Pitch drop caught in the act of falling in the Trinity College experiment (Photo: Trinity College)
Pitch behaves like a liquid when stressed slowly, but shatters like a brittle solid when struck with a hammer (Photo: University of Queensland)
The pitch drop experiment at the University of Queensland being watched by Professor John Mainsfield, current keeper of the experiment (Photo: University of Queensland)
The steely gaze of three webcams will help insure that the ninth drop of pitch from the University of Queensland pitch drop experiment will not go unnoticed (Photo: University of Queensland)
Is pitch a liquid or a solid? It turns out that while it appears to be a solid at room temperature, it actually flows like a liquid ... a very, very viscous liquid. Why is this interesting? One of the world's longest running experiments, which began nearly 70 years ago at Trinity College Dublin, has now recorded the fall of a drop of pitch on video for the first time.
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