Who invented the light bulb? Looking for evidence

Think of great inventors and Thomas Edison is most likely to come to mind. He was an extraordinarily prolific inventor with over a 1000 patents to his name. He invented the light bulb, now the iconic image for "bright idea"...but did he.

In fact it was the master of the public scientific performance, Humphrey Davy, who is credited with creating the electric light back in 1800, 80 odd years before Edison's invention. By connecting a piece of carbon to a battery (which he also invented), Davy was able to heat the carbon so much that it started to glow incandescently. Electric lights had arrived in the lab, but that didn't mean they were ready for the home.

Over the next 80 or so years there was a scramble to turn this basic science into a sellable product. Lots of people tried to invent practical light bulbs with varying success. The winner in terms of patents was actually a physicist from Sunderland, Sir Joseph Wilson Swan. He gained a patent in 1860 for a lamp he demonstrated. It was based on Davy's basic science using a carbon filament in a partial vacuum (modern light bulbs actually use tungsten filaments). He had problems with the vacuum though, so it wasn't really practical. By 1878 he was awarded a new patent for a much better design that lasted longer, though.

Edison didn't invent the version he is famous for until 1879. Its claim is not really about being the first light bulb but just the most practical up to that point in that it lasted 1500 hours before burning out. Edison also had the business savy to turn it into a marketable product. Swan successfully sued Edison for breaching his patent though, forcing Edison to take on Swan as a partner in his British business which became known as Edi-swan, so it really was Swan's invention.

The true story is always more complicated than a simple soundbite. Often the story that wins is the one favoured by the person who shouts the loudest or has most influence in the right places. That is why the scientific method is so important to make scientific results themselves trustworthy. Results have to be based on evidence not just the beliefs of those with most clout.

Maybe you should double check everything we've written here before you believe it as gospel too!