If U.S. lawmakers have their way, the lights may soon go out on Thomas Edison's greatest invention -- the incandescent light bulb. The 19th-century inventor brought illumination to the world's fingertips, but according to Congress, his invention isn't efficient enough for an age anxious about energy supplies. "Only 10% of the power used by today's incandescent bulbs is emitted as light, while the other 90% is released as heat," Rep. Jane Harman, D-Calif., said when she introduced her legislation to ban standard light bulbs. To eliminate this waste, Harman has proposed legislation that would effectively eliminate incandescent light bulbs from...