A 69-year-old experiment ended recently with a plop — a glob of asphalt, also known as bitumen or tar pitch, was caught on camera as it oozed from a funnel set up by a physicist at Trinity College in Dublin, Ireland.
The physicist wanted to find out whether the material was a solid or a liquid. In 1944, the question about a material commonly used as a sealant and adhesive was important. Now, other than in arguments about refining Canadian tar sands, bitumen is a back-shelf item.
The war ended, the transistor was invented, man walked on the moon, and we created home computers and sent a go-cart to Mars. Still, no one actually witnessed a drop falling — though over the years, eight globs of it wound up in the beaker.
Unsatisfied with the gravitational evidence that bitumen did indeed flow, Trinity College scientists set up a webcam to watch the experiment. It caught a drop falling on July 11 at 5 p.m. local time, or 10 a.m. here on the U.S. West Coast.
Scientists calculated the viscosity of the material to be about 2 million times more sticky than honey, according to the Nature report.
If you missed it, there's still a chance to catch a similar experiment in Queensland, Australia, that has been going on since 1927. There's a time-lapse video posted online of a drop descending from the University of Queensland experiment.