The invention of the lightbulb was a gradual process involving many inventors over several decades. However, Thomas Edison is often credited with inventing the first commercially practical incandescent lightbulb. Edison filed his first patent application for an "Improvement In Electric Lights" on October 14, 1878. After extensive experimentation, he successfully tested his incandescent lightbulb on October 22, 1879, with a test lasting 13.5 hours. He then filed another patent on November 4, 1879, for an electric lamp using a carbon filament. By early 1880, Edison had refined the design to use a carbonized bamboo filament that could last more than 1200 hours. Edison received the patent for his electric lamp on January 27, 1880. Though Edison is often credited with the invention, it is important to note that many inventors contributed to the development of the incandescent lamp before him, such as Humphry Davy, Joseph Swan, and others. Edison's key contribution was making a practical, reliable, and commercially viable electric lightbulb system.
