The development of artificial light

Master of Fire

The control of fire by early humans was a turning point in the cultural development of man. About 400,000 years ago, Neanderthals created fires with fireplaces for cooking, heating and making tools.¹ Light at this time was most likely just a by-product of the fire.

The first ‘lamps’ are said to come from about 40 000 years BC (numbers vary by a few thousand years depending on authors). Animal fat was burned in a small bowl of lime or sandstone and lichens or bark probably served as wicks. Such lams were found in rock paintings in caves in southern France.²

The candle - a first generation of lamps

By the beginning of about 500 BC, the romans made the first true dipped candles made from tallow, and wicks were made of bulrush, straw, hemp, papyrus or reed. Other civilizations (China, Japan, India) made candles from plants and insects.³

The Alexandria lighthouse, dating back to 260 BC, leading ships out of danger is a unique example of the early use of light. It is considered one of the seven wonders of the ancient world.⁴

Torches (initially using tinder), oil lamps and candles remained for millennia man’s only "artificial" light sources. By the middle of the 2^nd century AD, they were refined by the Romans: short wax candles that could burn in closed room without excessive soot and odour.

Access to artificial light meant extending the day into the night – a step into independence from natural light, to freedom.

Right up until the 19^th century, lamps were improved, but light and heat were always connected. In around 1862, coal gas, a by-product of mining, was used for street lighting. Today such a dim light would not be called bright.

The discovery of electricity

changed the definition of light and lighting. During initial experiments with what is called the arc lamp, which produced bright light for several hours, Humphry Davy invented the carbon arc lamp in the first decade of the 1800s. In 1879, Thomas Alva Edison developed a more durable filament lamp with bamboo charcoal fiber which increased the light span to about 40 hours. Ten years later, Carl Auer created the metal filament lamp, whose bright long-lasting light then became the standard. The next step to the revolution of electric lighting began when Edison combined systems of power generation and distribution, making electric light (unlike the flammable gas lamps) suitable for indoor lighting.

Osram (derived from osmium and tungsten - in German wolfram) was founded in the early 20th century by Siemens and AEG, the first major lighting group in Europe. However, at this point, electricity was still a luxury: in the 1920s, only half of even a large city like Berlin was connected to the electric grid, and it was not until the 1940s that electricity was readily available in Germany. In fact, we are only the second generation to have artificial lighting in our daily lives!

Widespread accessibility to light revolutionized the labour market: shift and night work were introduced. Streets came alive at night and the private household was completely independent. Fire dangers were eliminated - electricity was considered clean, practical and modern.

Light became a market with a future - and in 1929 the Phoebus cartel, the first global cartel, divided the market among the major light manufacturers in Europe and the United States (cartel included General Electric, Philips, Osram.) The illegal pricing and marketing agreements, along with the standardisation ie shortening the lifespan a light bulb 1 000 hours, led to lawsuits in 1942 against the respective companies involved in the cartel. These decisions also resulted in the standardisation of the bases of the E14 and E27. With the onset of the war in the US, the cartel was officially dissolved.⁵

The great lightbulb conspiracy became a controversial issue – it was often argued that a bulb was less efficient due to its shorter life span. The famous ‘Centennial Bulb’⁶ has been burning continuously in the Livermoore/California police station since 1901. However, this bulb use can hardly be compared to daily use (being switched on and off). Nevertheless, such examples show that the technical ‘facts’ and standards are often not as clear and undisputable as it is claimed.

After electricity became a widely available commodity during the post war period, the oil crisis and disputes about use of coal and nuclear power in the 1970s, exposed that our resources are in fact exhaustible.

At this time, the main concern in lighting technology was to reduce the energy consumption of incandescent lamps and bring new inventions to the market. Energy efficiency was and is considered the leitmotif of light development. General principles are described below and information about different types of lamps here.

To limit the enormous heat consumption of the incandescent lamp, the glass bulb, encasing the filament is located, was made smaller and filled with halogen gas, which provided a higher light output. The halogen bulb works in principle like the bulb but consumes about 30% less energy. In 1959, the first patent was issued for a halogen incandescent lamp.

In addition to thermal radiators

as of 1938, discharge lamps were manufactured. These are ‘neon tubes, fluorescent lamps filled with gases and compact fluorescent tubes were developed for household use. In 1980, Philips put a curved shape fluorescent tube on the market as an ‘energy-saving bulb’ on the market and expected it to replace the bulb. However, since these bulbs had strong green tones, taking away cozy aspect of the other bulbs, manufacturers were disappointed that the sales of energy saving bulbs were not as high as expected. Furthermore, they are controversial because of their mercury content. However, the discharge lamps, generate light through a chemical-electrical process, so there is but a little heat given off by the light.

Third light generation

Began in 1993, with the invention of the LED (light emitting diode, light emitting diode). Light no longer is created with moving gases, but from semiconductor crystals. LEDs emit highly directional light with the help of optics, each of which has a very specific colour (monochromatic light). From the 1970s onwards, red, yellow and green diodes were produced which had a very low power, so that they were only used in the signaling technology (for example for the control of light barriers), for calculators and digital clocks. White light can not be generated with the LED technology. Only the Japanese development of very energy-efficient blue LEDs in the 1990s made the LED interesting: when blue LEDs shine on a converter dye (usually phosphor), "white" light of all color temperatures can be brought to light with low energy consumption. The use of the LED in all areas of lighting technology could begin. Isamu Akasaki, Hiroshi Amano and Shuji Nakamura received the 2014 Nobel Prize in Physics for the use of effective semiconductors in LED lighting technology.

The artificial (electric) light has a brief history of the last hundred years. We are only the second generation with electric light and many of the consequences of our brighter world are only slowly coming to light ...