Real risks of real life don't always involve airplanes and nuclear power plants. Dr. M. Elisabeth Paté-Cornell shares a personal example: She has a two-year-old little boy who likes to tumble down the stairs in her new home. If that doesn't sound dangerous enough, the landing also has a sharp post. Dr. Paté-Cornell uses risk analysis to calculate the number of times her son might tumble down the stairs, the accident rate and possible solutions. The result: She builds a bumper of three baskets that can absorb the force of a basketball without breaking.