The Pitch Drop Experiment

Pitch Drop Experiment

At the University of Queensland in Australia there is an experiment going, an experiment that is now in the Guinness Book of World Records for "Longest Running Laboratory Experiment." It is the experiment of the pitch drop.

What Is Pitch?

It is actually an incredibly useful material. It is made from trees by heating up the wood, what drips away from the heated wood is pitch, something that looks like charcoal. Pitch was once used for sealing boats and ships by putting pitch between the timber. Pitch was also commonly used for torches by wrapping pitch around the end of a stick and lighting it on fire. It burns for a very long time and was used frequently even before we used candles. To get an idea of how long people have been using pitch for everyday use, in the story of Noah's Ark God tells Noah to cover the inside of the boat with pitch to waterproof it. Man has been using pitch long before any even remotely modern techniques.

pitch What natural pitch looks like

The Experiment

Professor Thomas Parnell was trying to convince his students that pitch was actually a fluid. A substance that looks like rock and can be shattered with a hammer is actually a fluid. In 1927 Parnell took some pitch and heated it up, he then poured it into a sealed glass funnel. Parnell then waiting 3 years for the pitch to settle and cut the stem off the funnel to allow it to drip. It has now been dripping for 87 years. In that 87 years it has only dripped 8 times. See, pitch is called a viscoelastic polymer, which means it's not a solid but an extremely viscous fluid. Pitch is estimated to be 100 billion times more viscous than water. Radiolab featured this story on their program and since then this experiment has acquired a sort of cult following.

Why?

Radiolab lays this out really well and you should absolutely listen to the episode about the pitch drop. However, one of the most intriguing things about this experiment is that no one has ever seen the pitch drop. It has always dropped right when no one is watching. The last drop in 2000 had a camera on it so that even if someone was not there to see it they could watch it later. But, right before the pitch dropped the camera failed and by the time they got the camera turned back on it was too late. So here we are it's 2014 and the ninth drop is about to fall. You could be the first person to actually watch the pitch drop, there is a live webcam you can tune into 24/7 to watch the pitch slowly dripping. The amazing thing is that when you tune in and watch this webcam you are watching an experiment that has been going on, and is still going on, since before even your grandparents were born, before WWII, before the empire state building was built, and before Amelia Earhart was lost at sea. The pitch drop experiment has been slowly dripping through so many of the historical events that we learn about in school and if we are lucky we can be a part of it and catch the ninth drop.

tagged with Mixer Direct Education, experiment, pitch drop, pitch