Strength, a powerful word, but what does it mean? How is it measured? Why are some things simply stronger than others? How strong is a rope, a tractor, a diamond, a tugboat or even plastic? From Spectra fibre to Lexan learn where, how and why strength matters to us every day.

Originally released by A&E Networks, 2006. Streaming video file encoded with permission for digital streaming by Infobase on May 16, 2015.

Introduction to Tractor Racing (5:21); --World's Strongest Tractor, The (4:00); -- Spider Silk (4:31); -- World's Strongest Ropes (2:48); -- Manufacturing Plasma Rope (4:41); -- World's Strongest Tug Boats (3:22); -- Tugboat Propulsion Systems (4:33); -- Strongest Natural Substance In the World, The (7:30); -- Strongest Plastic In the World, The (3:13); -- History of Plastic (3:10); .