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In 1800 (exact date unknown), an Italian inventor named Alessandro Volta was the first person to discover how to effectively generate electricity when he used alternating disks of copper zinc (voltaic pile), which conducted electricity when a copper wire was connected at either end of the pile.
http://www.livescience.com/43424-who-invented-the-light-bulb.html -
In 1802 (exact date unknown), Humphry Davy connected wires to a battery and a part of carbon when the carbon emitted light, thus leading to the invention of the electric battery.
http://www.bulbs.com/learning/history.aspx -
In 1835 (exact date unknown), James Brown Lindsay showcased his invention, a constant electric light (in an actual light bulb) to a meeting where he stated that he could read a book using the light, however, with a limited distance of 1 1/2 feet.
http://www.gizmohighway.com/history/light_bulb.htm -
In 1841 (exact date unknown), Frederick de Moleyns developed the first incandescent lamp (and received the patent for it) by using powdered charcoal that was heated between two platinum wires.
https://www.britannica.com/technology/incandescent-lamp -
In 1878, Joseph Wilson Swan demonstrated his light bulb during a lecture in England. The light bulb was not a steadily working invention as it lasted a mere 13.5 hours due to its inability to connect to an electric source and the lamp caused soot to form on the inner surface, causing the light to appear dim.
https://www.wired.com/2009/12/1218joseph-swan-electric-bulb/ -
Using a carbon filament, which emitted light when heated by an electric current, Thomas Alva Edison was able to demonstrate his invention of a long-lasting light bulb in 1879 at a public demonstration. Although he had used a platinum filament a month before, platinum was too expensive, and thus, he replaced it with carbon, which could provide sufficient light at an affordable price.
http://www.americaslibrary.gov/jb/gilded/jb_gilded_edison_3.html -
In 1911 (exact date unknown), William D. Coolidge, along with his company General Electric, began to replace the carbon filaments that Edison's bulbs had used in favor of longer-lasting and brighter tungsten filament light bulbs.
http://www.delmarfans.com/educate/basics/who-invented-light-bulbs/ -
(exact date unknown) In 1962, a General Electric engineer named Nick Holonyak constructed a LED (light emitting diode), which emitted red light and worked with a semiconductor laser to convert electric currents into light. Without his invention, CD and DVD players would not exist today as well as the millions of LED light bulbs which are still used today.
http://www.gelighting.com/LightingWeb/emea/news-and-media/news/First-LED-by-the-GE-engineer-Nick-Holonyak.jsp -
In 2011 (no specific date), the L-Prize Competition, designed to encourage further development for energy efficient light bulbs, declared a company called Philips Lighting the winner of the competition in the 60 watt category, due to their bulbs that lasted for over 20 years and cost $40. Since then, these LED light bulbs have saved $675 million in annual costs and over 49 million have been used.
http://www.delmarfans.com/educate/basics/who-invented-light-bulbs/
