Ask the question, ‘Who invented the lightbulb?’ and most people will say Thomas Edison; and if they’re really good at remembering their facts, they’ll add that it was in 1879. This is generally what we’re taught in school but the story actually starts much earlier.
In the early 1800s, Humphrey Davy created an electric lamp that used a spark between two charcoal rods connected to a battery, which became known as an Arc Lamp. It was unfortunately, too bright to be used in most homes and needed a lot of power, so instead ended up being used in lighthouses and later, for searchlights to spot enemy planes in the war.
For a while, inventors tried to lengthen the light source. Warren de la Rue tried platinum coils in a vacuum tube and when a current went through it, it lit up. Unfortunately platinum wasn’t cheap, so once again this wasn’t useful for homes or businesses.
By now, scientists knew that passing electricity between two materials would light up and therefore, glow. If that lasted too long though, chances are the material would then melt or catch fire… not so good. As we know, fire needs oxygen, so they decided that by keeping oxygen out of the equation they might solve their unfortunate fire issues. Several inventers, including Joseph Swan, patented ‘bulbs’ which would keep the burner in a glass contained and expel the air, so making a vacuum. After early failures due to the poor vacuum pumps of the time, Swan’s carbon paper filament bulb was finally patented in 1878 in Britain and became widely used in people’s homes.
In swoops the already popular inventor, Edison. After a few failed attempts, he finally had a breakthrough by using carbonised sewing thread as a filament. Doing this produced a lightbulb that burned for over thirteen hours and if the filament was bent, over 100 hours! He tested thousands of materials and came up with a filament made of bamboo which lasted over 1000 hours, almost as long as our bulbs last today.
So although Edison patented the first long lasting, useful bulb, it was based on one Joseph Swan had patented long before. Swan, understandably got a little upset at this and sued Edison for patent infringement and as a result, Edison was forced to make swan a partner in his company. Really, neither one of them are 100% responsible; the credit lies with numerous inventors and scientists who, through trial and error, founded something that we would find it incredibly difficult to live without.
The Bulb Today
Incandescent – We still use incandescent bulbs today, although we’re moving towards more energy efficient lighting. Incandescent bulbs work by heating a tungsten filament until it glows.
Halogen – Halogen bulbs are similar to incandescent but they can produce the same amount of light but use less energy to do so, making them longer lasting and more energy efficient than their incandescent counterparts.
Florescent – These are really common in households today. Florescent bulbs generate their light by heating up argon and mercury gas contained inside the tube. They are super-efficient when it comes to energy and produce the same amount of light as other bulbs.
LED – The most energy efficient and long lasting bulb that you can get, LEDs move electrons through a semiconductor, creating photons which we see as light. They can be more expensive but are 90% more efficient compared to some incandescent and last for tens of thousands of hours, saving you tons on replacements!