As every third-grader knows, Thomas Edison invented the electric lightbulb. Or did he? It’s painful to cast aspersions on the reputation of one of America’s heroes, but Edison, who patented his bulb in 1879, merely improved on a design that British inventor Joseph Swan had patented 10 years earlier. Swan sued Edison for patent infringement, and the British courts ruled against Edison (as punishment, Edison had to make Swan a partner in his electric company). Even the U.S. Patent Office decided in 1883 that Edison’s patent was invalid, as it also duplicated the work of another American inventor. As it happens, Swan and Edison worked from bulb designs that had been in use since the early 1800s. The general principle was, and still is, this: When electrical current flows through the bulb’s filament, the filament heats up and glows, which produces light. The inside of the bulb is a vacuum, hence oxygen-free, so the filament doesn’t get oxidized and the glow lasts a long time. Swan used a carbonized paper filament, but the poor quality of the vacuum in the bulb caused the carbon to disintegrate rapidly, so the bulb glowed for just 13-and-a-half hours. Edison used a better vacuum pump, and after he and his posse of assistants had tested thousands of materials, he made a filament derived from bamboo that lasted up to 1,200 hours. Today’s incandescent bulbs, in which the filament is made of tungsten, last about 1,500 hours. Related content Feature AMD takes hybrid approach to engineering the cloud’s future To ensure AMD can power a more powerful public cloud, CIO Hasmukh Ranjan embraces two worlds: cloud-fueled business transformation and massive engineering workloads on the ground. By Paula Rooney Mar 31, 2023 7 mins Technology Industry High-Performance Computing Digital Transformation Feature Best business analyst certifications to level up your career Business analysts blend data skills and business acumen to the benefit of analytics-driven organizations. Here are 13 noteworthy certs to help you get ahead as a business analyst. By Sarah K. White Mar 31, 2023 12 mins Business Analyst Certifications IT Skills BrandPost Are tech layoffs inevitable, or can your company avoid them? Despite tech industry layoffs, one ITSM company remains committed to growth and expansion of internal teams. The company’s successful endeavor is largely credited to one difference between TOPdesk and other tech organizations. By TOPdesk Mar 30, 2023 6 mins IT Leadership Analysis CIOs must evolve to stave off existential threat to their role With LOB leaders learning tech faster than CIOs gain business-savvy, IT leaders must strengthen advisory skills, build relationships, and embrace strategic transformation before losing out to business counterparts. By Yashvendra Singh Mar 30, 2023 10 mins Roles Podcasts Videos Resources Events SUBSCRIBE TO OUR NEWSLETTER From our editors straight to your inbox Get started by entering your email address below. Please enter a valid email address Subscribe