Thomas Edison demonstrated his incandescent light bulb at his lab in Menlo Park, New Jersey, to the delight of 3,000 onlookers on New Year's Eve, 1879 - that's 132 years ago, for those who are counting. Of course, the rest is history, as the electricity juggernaut took over and lit up our world, with man-made light to rival the stars. Through a unique combination of insight and persistence, Edison economically and practically conquered the dark, changing the face of our planet and earning a special place in history, revealing his accomplishment to the public on this very night, four generations ago. The Writer's Almanac covers it well.

Edison didn't invent the light bulb — incandescent lights had been around for almost 40 years — but he was the first come up with a practical, long-burning design. He realized he was on the right track by the end of October, when he tested a carbonized filament inside a glass vacuum bulb, which produced a light that burned for more than 13 hours. He kept fiddling with it and modifying it, and each version burned a little bit longer than the one before it; by the time he was ready to reveal it to the public, his bulb was burning for 40 hours.

After 14 months of testing, 1,200 experiments, and $40,000, he was finally ready for his first public demonstration. He hung strings of lights inside his lab in Menlo Park, New Jersey, and switched them on and off repeatedly, to the awe and delight of his 3,000 spectators. He said, "We will make electricity so cheap that only the rich will burn candles."

While we should give Edison all due credit for his work on the light bulb (and so much more), I have to point out that he was less accurate in forecasting the cost of electricity / price of candles... we still have a long way to go in making electricity universally available and affordable to the world - note the dark areas on the attached graphic. Let us resolve to carry on Edison's tradition and employ our collective creativity to banish the darkness for all mankind.