Drip from Tar-Pitch Experiment Seen After Decades of Waiting

By Breanna Draxler | July 19, 2013 5:11 pm

pitch drop experimentThe drip has dropped! (Or has the drop dripped?) Either way, the curse of the 69-year-old pitch-drop experiment has finally been broken: physicists at Trinity College in Dublin have finally caught the falling drop of asphalt on film for the first time ever, without a malfunctioning camera or an ill-timed tea run thwarting their plans. And it’s a good thing they have videographic proof this time because it’ll be another 7 to 13 before the pitch drips another drop.

The sticky black tar pitch, also known as asphalt, is an über thick liquid that flows reeeeeeeeeally slowly. The Dublin pitch-drop experiment was set up in 1944, and is a riff off an earlier Australian demo set up in 1927, but very few people have been watching it with rapt attention during those decades. In fact, for a while it was forgotten, collecting dust instead of accolades. But no more! Physicists at Trinity College finally caught the drop on tape on July 11. They estimate the viscosity (resistance to flow) of tar pitch is 2 million times greater than that of honey and 20 billion times the viscosity of water, as reported in Nature today.

Image and video courtesy of Chris Heller/Trinity College

CATEGORIZED UNDER: Space & Physics, top posts
MORE ABOUT: physics, viscosity
  • Buddy199

    So why don’t these guys have girl friends?

    • Ryan Mercer

      Why do you assume they are all men? Or heterosexual for that matter? You’re not real interested in learning, are you?

      • Buddy199


    • Sisi Ville

      Many of them are married. I’m sure their wives wouldn’t appreciate them having girlfriends.

  • Hisham ElDai

    I am really very curious trying to be educated on the purpose of this experiment or the applications of this in physics beyond the theoretical realm… Something the writer could’ve just alluded to briefly in his closing line…

    • lisa741

      as Steven replied I’m dazzled that some one able to earn $8045 in 1 month on the computer. have you seen this web link w­w­w.K­E­P­2.c­o­m

    • drchuck1

      these types of experiments are for those with little knowledge of science…it shows what appears to be a solid is actually a liquid…an example of the obvious not always being the whole story…a valuable lesson for everyone to keep in mind

      • Hisham ElDai

        If you’ve ever worked with tar or have seen ppl workhor with it. Say in construction for example you’ll see that it’s liquid or semi solid depending on temperature. What application can that have is a lot because UC is less viscous than water then it’s a good in proofing roofs but that it’s too heavy is a disadvantage.

    • http://blogs.discovermagazine.com Breanna Draxler

      These types of experiments are often called “demonstration pieces.” The researchers use them to show how something works in real life.


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