Because we use water all the time, most of us have an intuitive sense of how long it takes a drop of water to form and fall. More viscous liquids, like oil or shampoo or honey, drop more slowly depending on how thick they are, which can vary depending on concentration, temperature and more. If you’ve ever tried pouring molasses, you know why it’s used as a metaphor for something moving very slowly, but we can easily see a drop of any of those liquids form and fall in a matter of seconds.
But what about the most viscous substance in the world? How long does it take to form a falling drop? A few minutes? An hour? A day?
How about somewhere between 7 and 13 years?
Pitch moves so slowly it can’t be seen to be moving with the naked eye until it prepares to drop. Battery for size reference.John Mainstone/University of Queensland
