Science 7 & 8 classes tried building bridges and towers from spaghetti, straws, plasticene, and marshmallows. Here are a few of their designs. Some were more successful than others. The class discovered that soft marshmallows don't work well with large structures ... the straws weren't held firmly enough to prevent sideways motion. Similarly, long pieces of spaghetti tended to flex too much. Only the best designs using marshmallows or spaghetti avoided tipping. Plasticene worked well as a connector, and provided good lateral (shear) strength The tower designs had to hold a golf ball for twenty seconds without collapsing. Some structures disintegrated in spectacular fashion. Several students realized that a wide base places the centre of mass in a position less likely to cause the structure to tip over. Structures were also tested for their resistance to shear forces by a massive application of well-placed hot air. Introduction Bridge Structures | Bridge Photos | Using Toothpicks | Marshmallows | Make a Plan