Fire

Lore & Background

Fire is one of the four classical elements and has been used throughout human history for purposes that now include cooking, generating heat and light, clearing land for agriculture, signaling, propulsion, smelting, forging, incineration of waste, cremation, rituals, weapons, and destruction, including in warfare. The word fire comes from Old English and has cognates in many Germanic languages and other Indo-European languages. The Proto-Germanic nominative form is reconstructed as , descending from Proto-Indo-European . An alternative spelling existed in Middle English: ; still preserved in fiery. The word ignite is derived from the classical Latin ignis meaning fire. The Greek term for fire, pyr, is used in words such as pyroclastic or pyrotechnic.

Reader's Guide

Fire, in its most common form, has the potential to result in conflagration, which can lead to permanent physical damage. Fire directly affects land-based ecological systems worldwide. The benefits of fire include stimulating plant growth and maintaining ecological balance. Its harms include hazards to life and property, atmospheric pollution, and water contamination. When fire removes protective vegetation, heavy rainfall can cause soil erosion. The burning of vegetation releases nitrogen into the atmosphere, unlike other plant nutrients such as potassium and phosphorus, which remain in the ash and are quickly recycled into the soil. This loss of nitrogen produces a long-term reduction in the fertility of the soil. However, it can be recovered by nitrogen-fixing plants—some of them of agricultural value, such as clover, peas, and beans, by decomposition of animal waste and corpses, and by natural phenomena such as lightning. Various technologies and strategies have been devised to prevent, manage, mitigate, and extinguish fires, with professional firefighters playing a leading role. For example, most home fires start from unattended cooking, although cigarettes are another major cause. Smoke detectors and sprinkler systems greatly reduce harm from home fires.

Did You Know?

• The fossil record of fire first appears with the establishment of a land-based flora in the Late Silurian period.
• Wildfire is first recorded in the Late Silurian fossil record by fossils of charred plants.
• The oldest clear evidence of deliberate firemaking dates to around 1.5 million years ago at the Koobi Fora site in Kenya.
• Globally today, as much as 5 million square kilometres – an area more than half the size of the United States – burns in a given year.