The Lightbulb 

Thomas Edison is often — and incorrectly — given all the credit for inventing the lightbulb. But the lightbulb was actually the result of a processthat began before Edison was even born. In 1802, English chemist Humphry Davy used a voltaic pile(invented by Alessandro Volta, after whom the volt is named) to create the first “electric arc lamp” between charcoal electrodes. His rudimentary lamp was too bright and burned out too quickly, but it was nonetheless an important breakthrough. Other scientists worked to refine the lightbulb, but problems with filaments and batteries made these early bulbs impractical for everyday use. In 1860, English physicist Joseph Swan developed a primitive electric light that utilized a filament of carbonized paper in an evacuated glass bulb. Lack of a good vacuum and an adequate electric source ultimately made it inefficient, but it did pave the way for later innovations, including those by Edison. Edison purchased some of his predecessor’s patents, improved upon them, and came up with his own lightbulb, which, while not the first overall, was the first to be commercially viable.