The history of the invention and evolution of the light bulb bears testimony of the endeavors of many scientists, physicists, and even chemists. The history of light bulbs is as old as two centuries. Sir Humphrey Davy worked out a formulation for the electric arc that resulted in Davy's miner lamp.
In 1802 he first demonstrated the working of the electric arc using 2 wires, one end of which was attached to a narrow thin piece of charcoal and the other to a battery. In 1820, Warner de la Rue used a coil made of platinum in an empty tube, passed an electric current through the coil and produced the first light bulb. Such a bulb was not commercially feasible, as platinum is a very expensive metal.
Research to find the right kind of filament was being worked out by many scientists. However, it was James Prescott Joule who first propounded that electric current when made to pass through a conductor with high resistance yields thermal energy, which can generate light energy or become luminous. The quest began to find the right filament, which was inexpensive, practical, commercially viable, and not too big. In 1840, Joseph Wilson Swan, an English physicist and chemist, developed the first practical working electric light bulb using a carbonized paper filament in partial vacuum. He patented this incandescent lamp in 1860.
However, this bulb produced fairly dim light, was not long-lasting, and had to be close to the power source. In 1874 he demonstrated an improvised version. However, Thomas Eliot made it commercially feasible in 1875 using similar technology. Eliot worked relentlessly to improve the light bulb. In 1880 he introduced a bamboo fiber filament lamp. With the use of a vacuum pump invented by Herman Spiegel he was successful at creating a complete vacuum inside the lamp chamber. The presence of oxygen was known to oxidize the filament and affected the life of the bulb.
The shape of the glass bulb that was used was originally designed by Henry Woodward and Matthew Evans. During this time scientists were working on a new form of electric arc lamp, the discharge lamp, first by using carbon dioxide inside the bulb and later by inserting a noble gas like argon or krypton. This was done to enhance the efficiency of the light bulb.
In 1901, Peter Copper Hewitt invented a lamp of mercury vapor, which emitted a bright bluish-white light. Later, a brighter sodium vapor lamp was invented. In 1903, Willies Whitney introduced a metal coating for the carbon filament to prevent it from getting charred and burned, and in turn blackening the bulb. In 1906 General Electric introduced the tungsten filament, which had a high melting point.
Although Eliot was aware of this metal and its use, there was no machinery to develop it during his time. In 1910 another engineer from General Electric, William David Coolidge, invented a tungsten filament with a longer life. The 1920s saw the invention of frosted light bulbs, which were used for cars and neon lights. In 1930, photographic flash bulbs and fluorescent bulbs were invented. The 1940s saw the invention of soft incandescent light bulbs and the 1950s saw the invention of quartz glass that was later used in halogen bulbs. The 1960s and 1970s paved the way for metal halide lamps, ellipsoid reflectors and mirrors, which were used to produce brighter lamps. In 1990 the Philips company invented a 60,000-hour bulb with magnetic induction, and later it also introduced the full-spectrum light bulb.
In modern times, scientists are working around the clock to develop more-energy efficient, power-saving and environmentally friendly bulbs.
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