Waiting on a Different Time Scale

From “A Test of Patience,” by Mats Bigert, Cabinet Magazine, Issue 34, Summer 2009:

Pitch Drop Experiment The Pitch Drop Experiment was initiated in 1927 by Professor Thomas Parnell of the University of Queensland in Brisbane, Australia, to demonstrate for his ­students that some substances that appear to be solid are actually fluid. A heated sample of pitch, a naturally occurring petroleum substance, was poured into a funnel-shaped glass container and sealed. After three years, the sample had apparently coagulated and it was time to kick-start what is now the longest-running, and what must surely be one of the slowest, laboratory experiments in history. Parnell unsealed the funnel and the pitch was free to flow. After a couple of years, a drop began to form, but it took eight years for it finally to fall, the student audience of the experiment having long since graduated. The experiment continued, nevertheless, since it required no maintenance, and every eight or so years, a little baby drop left the nest of mama pitch for the growing expanse of papa pitch below. Eventually, after the eighth, and most recent, drop fell on 28 November 2000, the viscosity of pitch was finally calculated to be roughly one hundred billion times that of water.

To date, no one has ever witnessed an actual drop fall and there is no visual documentation of the dramatic event. The closest anyone has ever come was in April 1979 when Professor John Mainstone, who now maintains the experiment, came­ to work on a Sunday afternoon. He noted that the pitch drop was just about to touch down, but he did not have time to stay and watch. On returning the following morning, Mainstone saw, much to his chagrin, that the drop had fallen. Even modern technology has been foiled in its attempt to capture direct evidence of the pitch’s clandestine maneuvers; a video camera placed to monitor the experiment happened to fail at the very moment the eighth drop fell.






Experiment set up



The stem was cut


December 1938

1st drop fell


February 1947

2nd drop fell


April 1954

3rd drop fell


May 1962

4th drop fell


August 1970

5th drop fell


April 1979

6th drop fell


July 1988

7th drop fell


28 November 2000

8th drop fell