Light and Warmth

Light, Warmth and the End of the Age of Tungsten

Since humans first learnt to control fire a million years ago, people have created artificial light through heat. For most of that time, the naked flames of open fires, candles and oil lamps have illuminated nature’s darkness; in the nineteenth century, gas lighting brought new ways to distribute and control the fuel, but the fundamental mechanism for generating light was the same. The twentieth century saw the widespread adoption of electric lighting, made readily available by the invention of the tungsten filament lamp. Tungsten has the highest melting point of all metals, and in such lamps the filament is heated by electricity, replacing the glowing particulates of a naked flame with heated metal, producing light through the process known as incandescence.

Throughout the twentieth century, domestic lighting, and much public, commercial, industrial and stage lighting, was dominated by the tungsten lamp. Newer light sources gradually emerged, using different physics: discharge and fluorescent lamps made light by passed electricity not through a metal filament but through selected gasses enclosed in a glass envelope – a process not of incandescence but of luminescence.

Now, the twenty-first century is completing the revolution in how we create light. The introduction and widespread adoption of the light emitting diode (LED) as a light source means that for the first time in human history, luminescence (generating light without heat, or β€˜cold light’) has replaced incandescence as the primary means of illumination. The intimate relationship between light and warmth has finally been broken.

The Light and Warmth project is launching in Autumn 2022 - see the dedicated Light and Warmth project website for the latest news.