<Tr> <Td> </Td> <Td> Look up pitch in Wiktionary, the free dictionary . </Td> </Tr> <P> Pitch is a name for any of a number of viscoelastic polymers . Pitch can be natural or manufactured, derived from petroleum, coal tar or plants . Various forms of pitch may also be called tar, bitumen or asphalt . Pitch produced from plants is also known as resin . Some products made from plant resin are also known as rosin . </P> <P> Pitch was traditionally used to help caulk the seams of wooden sailing vessels (see shipbuilding). Pitch may also be used to waterproof wooden containers and in the making of torches . Petroleum - derived pitch is black in colour, hence the adjectival phrase, "pitch - black". </P> <P> Naturally occurring asphalt / bitumen, a type of pitch, is a viscoelastic polymer . This means that even though it seems to be solid at room temperature and can be shattered with a hard impact, it is actually fluid and will flow over time, but extremely slowly . The pitch drop experiment taking place at University of Queensland is a long - term experiment which demonstrates the flow of a piece of pitch over many years . For the experiment, pitch was put in a glass funnel and allowed to slowly drip out . Since the pitch was allowed to start dripping in 1930, only nine drops have fallen . It was calculated in the 1980s that the pitch in the experiment has a viscosity approximately 230 billion (2.3 × 10) times that of water . The eighth drop fell on 28 November 2000, and the ninth drop fell on 17 April 2014 . Another experiment was begun by a colleague of Nobel Prize winner Ernest Walton in the physics department of Trinity College in Ireland in 1944 . Over the years, the pitch had produced several drops, but none had been recorded . On Thursday, July 11, 2013 scientists at Trinity College caught pitch dripping from a funnel on camera for the first time . </P>

What is the difference between sap and pitch