SCIENCE
'(<a href="http://www.j-archive.com/media/2011-11-29_DJ_13.wmv">Sarah of the Clue Crew gives the clue as she and Kelly demonstrate a potato gun.</a>)  A potato gun demonstrates Boyle's Law using a simple tube & a stick; pushing the stick reduces the volume of air and increases this 8-letter term, making the potato go ballistic'
pressure