 When he was just 14 years old, Malawian inventor William Kamkwamba built his family an electricity-generating windmill from spare parts, working from rough plans he found in a library book. Josh Silver delivers his brilliantly simple solution for correcting vision at the lowest cost possible -- adjustable, liquid-filled lenses. Too much of the world lacks access to clean drinking water. Engineer Michael Pritchard did something about it -- inventing the portable Lifesaver filter, which can make the most revolting water drinkable in seconds. If you have a accident and need medical treatment, how does the insurance pays for the hospital costs and relative fees ? |
