Thomas Edison had little in the way of formal schooling, but a lot of self-taught talent. His first science experiments came at home from a book his mother got him, stimulating and developing his love of science. In his youth, working with the telegraphs led him to invent ways to improve them. Already an accomplished inventor, he moved to Menlo Park to work on improving another technology, the incandescent bulb – the early models available then gave off too bright a light for small rooms. Edison tried thousands of different techniques before finally finding the one that worked.

On this day, December 31, in 1879, several months after discovering the perfect incandescent light bulb, burning longer and with less power than conventional models, Thomas Edison unveiled them to the public.

Edison settled on using filaments – thin strips of material, which would glow when electricity is passed through them in an airless bulb – to make his light bulb. The only question was what would be the best filament material, and here Edison had no idea. His discovery came from the brute force method: he and his assistants made them out of thousands and thousands of different materials, testing each one. Was he ever frustrated by the scores of failures along the way to his invention? “The electric light … required the most elaborate experiments,” he wrote. “I was never myself discouraged, or inclined to be hopeless of success. I cannot say the same for all my associates.” He added later, “Genius is one percent inspiration and ninety-nine percent perspiration.”