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Using data recovered from a damaged computer hard-drive that was aboard the ill-fated Space Shuttle Columbia in 2003, scientists have recently learned more about why the act of shaking a material can quickly transform it into something completely different.

One of the best examples of this phenomenon is ordinary ketchup. Shake the bottle and the semi-solid paste becomes a runny liquid. Food scientists do the shaking in a controlled way by putting ketchup (and other processed foods) into a rheometer (rheo, meaning "flow") to see how its viscosity -- the scientific word for stickiness -- decreases when shaken.

http://www.space.com/scienceastronomy/080502-ketchup-science.html