1 It's a convenience we use every day, usually several times a day. We walk into a room, flip on the switch, and presto - there is light!
2 The electric light bulb has been in use since 1879. Although other inventors had already developed the basic concept of the bulb, Thomas Edison was the man responsible for figuring out what kind of material would be best used for the filament (or wire) inside the bulb. The greatest challenge was to create a filament that would burn long enough so the bulb would provide light for an extended period of time.
3 Edison spent two intense years experimenting with such things as bamboo and silver before he finally stumbled upon the idea of using carbonized thread for the filament. This was ordinary cotton sewing thread burned to an ash. When an electric current was sent through the thread inside the bulb, it burned for an entire day providing a warm, bright glow. It would have burned longer; but Edison, being the curious inventor he was, increased the voltage of electricity to see how it would affect the bulb. Only then did it burn out. On December 21, 1879, news of Edison's invention of the electric incandescent light spread throughout the world.
1 It's a convenience we use every day, usually several times a day. We walk into a room, flip on the switch, and presto - there is light!