Building Better Bridges

ABOUT STRUCTURAL DESIGN: All modern high-rise buildings and most bridges feature something called redundant design: when one section fails, the entire structure should still be able to stand. It's a bit like a net: lose one string and the net will be weakened, but as a whole, the net still functions. Most high-rise buildings and bridges also are designed to sway in the breeze, because if the structure is too rigid it can snap under too large an impact.

DIFFERENT DEFORMATIONS: Different materials can withstand different amounts of deformation, a property known as elasticity. Most materials are elastic to some degree: when they are deformed or bent, they will bounce back to their original shape. But elastic materials all have their limits. Metal springs and rubber bands are very elastic. Plaster and glass are not; instead, they are brittle and snap even with a small deformation.

MATERIAL ISSUES: Materials science is the study of stuff -- the substances that make up things you use every day-- from your shoes, dishes, CDs, or your bicycle or skateboard. All are made from different kinds of materials. Materials derive their unique properties from atomic structure so materials scientists can manipulate atoms and molecules to design new kinds of stuff with different properties that could show up in the nifty gadgets, clothing and kitchenware of tomorrow.

The American Society of Civil Engineers and the Materials Research Society contributed to the information contained in the TV portion of this report.