The Light Bulb

Introduction

Thomas Edison is usually credited as the inventor of the light bulb. Indeed, the famous American inventor’s contribution to this revolutionary technology was hugely important, however we must realise that he was not the sole inventor of the light bulb. Many notable figures are also remembered for their work with electric batteries, lamps and the creation of the first incandescent bulbs. 

Early research & developments 

In 1802, an Englishman named Humphry Davy invented the first electric light. He experimented with electricity and invented an electric battery. When he connected wires to his battery and a piece of carbon, the carbon glowed, producing light. His invention was known as the Electric Arc lamp. However, while it produced light, it didn’t produce it for long and was much too bright for practical use.

In 1840, British scientist Warren de la Rue developed an efficiently designed light bulb using a coiled platinum filament in place of copper, but the high cost of platinum kept the bulb from becoming a commercial success. And in 1848, Englishman William Staite improved the longevity of conventional arc lamps by developing a clockwork mechanism that regulated the movement of the lamps' quick-to-erode carbon rods. But the cost of the batteries used to power Staite's lamps put a damper on the inventor's commercial ventures. 

In 1850 an English physicist named Joseph Wilson Swan created a “light bulb” by enclosing carbonized paper filaments in an evacuated glass bulb. And by 1860 he had a working prototype, but the lack of a good vacuum and an adequate supply of electricity resulted in a bulb whose lifetime was much too short to be considered an effective producer of light. However, in the 1870’s better vacuum pumps became available and Swan continued experiments on light bulbs. In 1878, Swan developed a longer lasting light bulb using a treated cotton thread that also removed the problem of early bulb blackening. 

In 1874, Canadian inventors Henry Woodward and Matthew Evans filed a patent for an electric lamp with different-sized carbon rods held between electrodes in a glass cylinder filled with nitrogen. The pair tried, unsuccessfully, to commercialize their lamps but eventually sold their patent to Edison in 1879. 

Thomas Edison and the “first” light bulb 

Edison and his team of researchers in Edison's laboratory in Menlo Park, N.J., tested more than 3,000 designs for bulbs between 1878 and 1880. However, he continued to test several types of material for metal filaments to improve upon his original design and by Nov 4, 1879, he filed a patent for an electric lamp with "a carbon filament or strip coiled and connected ... to platina contact wires." The patent listed several materials that might be used for the filament, including cotton, linen and wood. It was not until several months after the patent was granted that Edison and his team discovered that a carbonized bamboo filament could last over 1200 hours. This discovery marked the beginning of commercially manufactured light bulbs and in 1880, Thomas Edison’s company, Edison Electric Light Company began marketing its new product. 

Changing technology 

Nowadays, lighting choices have expanded and people can now choose between many different types of light bulbs. These include compact fluorescent (CFL) bulbs which work by heating a gas that produces ultraviolet light, as well as LED bulbs that use solid-state light-emitting diodes.