Tag Archives: Pitch Drop Experiment

The Slowest Pitch

pitchdropexperimentBaseball fans may know that the fastest pitch ever recorded was 105.1 miles per hour. The ball was thrown by Cincinnati Reds pitcher Aroldis Chapman in 2010. But what about the slowest pitch? Take a guess. You will probably be wrong by about a decade.

The slowest pitch ever recorded took over 11 years to travel an inch! No joke! It was the amazing result of the world’s longest running scientific experiment, going since 1927.

Okay, first you need to understand that a “pitch” is not just a thrown baseball. ‘Pitch” is also the name of a black gooey liquid made from petroleum (oil). Familiar types of pitch include tar, asphalt and resin.

What do I mean by calling pitch “gooey?” Scientists describe the gooey-ness of a liquid by measuring how fast it pours, and they call this number “viscosity”. The higher the viscosity, the slower it pours. Water has a viscosity of almost zero (0.00089), honey is 10, and ketchup is 100.

Scientists didn’t know the exact viscosity of pitch, but they knew it was really high, estimated to be about 100 million (100,000,000)!

In 1927, Professor Thomas Parnell at The University of Queensland, Australia, wanted to demonstrate to his students that pitch was really a liquid; and fortunately he had a lot of time. He heated up some pitch (which lowered the viscosity making easier to pour), and filled a glass funnel. He let it cool for three years, then opened the bottom of the funnel, and placed a small cup underneath to catch any drops. Then placed it in a display case outside his office, and he waited . . .

It took over ten years before the first drop fell. Over eighty years have now passed, and the experiment keeps going. So far 9 drops have fallen.

It has become known as the Pitch Drop Experiment, recognized by the Guinness Book of World Records as the longest running laboratory experiment in history.

A similar experiment was started at Trinity College in Dublin, Ireland, in 1944. It dripped in 2013 and the event was caught on film. Based on that drop, the viscosity of pitch was revised and calculated to be 218 million! Among other things, this more accurate measurement will allow scientists to design better, longer lasting and safer roads.

Fun Phineas Facts: The expression “pitch black” to describe complete darkness comes from the highly viscous liquid.

Pitch has at least four other completely different meanings besides baseball and tar.

  1. “to build” as in “pitch a tent”
  2. “a single musical note” as in “singing in perfect pitch”
  3. “a sports field” as in “Harry Potter’s quidditch pitch”
  4. “an advertisement” as in “a sales pitch”

Check out a 20 second time lapse YouTube video of the only drop of pitch ever filmed:


SOURCES

The Baseball Almanac

NEWS: The (U.K.) Independent: The Pitch Drops: Science experiment going for 69 years caught on film for first time

The University of Queensland – Australia – The Pitch Drop Experiment Page

WIKI: The Pitch Drop Experiment

WIKI: Pitch (Resin)

PODCAST: The Skeptics Guide to the Universe episode #419:


PHOTO CREDIT: Picture of the Pitch Drop Experiment at the University of Queensland, with 9-volt battery for size comparison (University of Queensland).