Electric light be made with a screw-thread base, two metal pins, two metal caps or a bayonet cap. The three main categories of electric lights are incandescent lamps, which produce light by a filament heated white-hot by electric current, gas-discharge lamps, which produce light by means of an electric arc through a gas, and LED lamps, which produce light by a flow of electrons across a band gap in a semiconductor. Before electric lighting became common in the early 20th century, people used candles, gas lights, oil lamps, and fires. Cornish chemist Humphry Davy developed the first incandescent light in 1802, followed
A Crude Awakening: The Oil Crash A Crude Awakening: The Oil Crash A Crude Awakening: The Oil Crash is a 2006 documentary film about peak oil, produced and directed by Basil Gelpke and Ray McCormack. "A Crude Awakening: The Oil Crash" explores key historical events, data and predictions regarding the global peak in petroleum production through interviews with petroleum geologists, former OPEC officials, energy analysts, politicians, and political analysts. The film contains contemporary footage interspersed with news and commercial footage from the growth heyday of petroleum production. The documentary focuses on information and testimony that supports the projection of a near-term oil production peak. The documentary