alternative_right shares a report from ScienceAlert: *It all started in 1927, when physicist Thomas Parnell at the University of Queensland in Australia filled a closed funnel with the world’s thickest known fluid: pitch, a derivative of tar that was once used to seal ships against the seas. Three years later, in 1930, Parnell cut the funnel’s stem, like a ribbon at an event, heralding the start of the Pitch Drop Experiment. From then on, the black substance began to flow. At least, that is, in a manner of speaking. At room temperature pitch might look solid, but it is actually a fluid 100 billion times more viscous than water.

It took eight years for the first droplet to finally hit the beaker below. Then, they dripped at a cadence of once every eight years or so, slowing down only after air conditioning was installed in the building in the 1980s. Today, 96 years after the funnel was cut, only nine drops in total have seeped out. The last was in 2014. Scientists expect another will fall sometime in the 2020s, but they are still waiting. No one has ever actually seen a droplet fall directly, despite all the watchful eyes. The experiment is now live-streamed, but various glitches in the past meant that each fateful moment has slipped us by.