Thomas Edison’s search for a filament for the lightbulb is quite inspiring. After trying two thousand different materials, his assistant complained, “All our work is in vain. We have learned nothing. Not sure if we can use an electricity properly.” Edison’s reply suggests that their failures had not gone to waste: “Oh, we have come a long way and we have learned a lot. We know that there are two thousand elements which we cannot use to make a good light bulb.” *We know the ending of this story. According to Edison’s account, “Before I got through I tested no fewer than 6,000 vegetable growths, and ransacked the world for the most suitable filament material. . . . The electric light has caused me the greatest amount of study and has required the most elaborate experiments. I was never myself discouraged, or inclined to be hopeless of success. I cannot say the same for all my associates.”
