Sunday, October 27, 2013

Watching pitch drop

For the past few days I have been participating in the world's longest running laboratory experiment. Started in 1927, the Pitch Drop experiment observes the properties of pitch, a derivative of tar, that appears solid at room temperature but is actually a fluid. After heating the pitch, Professor Parnell and the University of Queensland left the pitch to settle in glass funnel with a sealed stem and then in 1930, cut the sealed stem.

Since then the pitch has very slowly formed drops and these have fallen approximately every decade, however no one has actually observed any of the previous eight drops falling. In 1988 the 7th drop fell while the custodian was having a five minute break. In November, 2000, a webcam malfunctioned and missed capturing the 8th drop falling.

As shown in this time lapse video of the last 18 months, the drop changes very slowly.

My own observations, measuring the size of the drop with a screen ruler over the last few days show that it has grown less than a pixel in diameter.

Watch the pitch live below, or join the experiment at


Gerry said...

Interesting experiment!

ChuckD said...

Utterly mesmerizing, though perhaps the world's most boring job, to watch over this thing. Hope they catch the next one on camera!

Peter Murray said...

I have watched this for 160 hours now. The Christmas decorations and occasional students peering at the display break the monotony.