More than two million semis travel some 120,000 miles apiece along America's arterial highways every year at an average efficiency of just 6 MPG. Six. Miles per gallon of diesel—not even Hummers are that wasteful. However, a new "Super Truck" design by Peterbilt has shown it can go the same distance for half the gas.
23-year-old Emily Cummins started her career as an inventor as a young girl tinkering in her grandfather's shed. Now, thanks to a solar-powered fridge that's already in use across Africa, Nobel winners are handing her awards.