Fire was discovered by early humans by chance. How? Now we know that for a fire to be ignited, we have to heat up fuel like gas, wood, coal to a high enough temperature. One of the ways this can be done is by rapidly grinding pieces of fuel like wood against each other or against a hard surface. But early humans did not know this. They had no idea about fire or that friction could make fire. It is said that early humans, somewhere about 1 million years ago accidentally rubbed stone or wood together when a spark popped. It confused them, scared them in the beginning. Slowly they explored how useful this discovery was. It kept them warm, helped them cook meat and also kept them safe by scaring wild animals away.
What actually is fire? Fire is a chemical reaction that releases light and heat. Any fuel heated up to very high temperatures, when combines with oxygen in the air, produces a flame known to us as fire. The part of the fire we see is known as flame. Flames are of different colours depending on the substances burnt and also on their temperatures. Have you noticed a candle flame? It is blue coloured in the centre(closest to the wick) and yellow outside. It is because centre of the flame burns at a slight higher temperature that outside of the flame. Typically, a candle flame burns at around 1000 degrees Celsius. The process of burning something is called combustion.
We can’t imagine our world without fire today. The most common use of fire is in households for cooking. Fire is also used a fuel. It is used in power stations to create steam that drive turbines. These turbines in turn spin the electric generator that produces electricity. Have you notice rockets bursting into space while emitting fire from the base? Space crafts are propelled in space today using fire as an important tool.
However fire can be particularly dangerous and destructive too. It is very important for humans to use fire with caution as it easily burns human skin. The resulting blisters are extremely painful. Ouch! Wildfires in woods resulting from extremely dry temperatures are immensely destructive for wildlife.
Fires can be extinguished in three ways. By either removing the fuel source from a burning fire or by cutting the supply of oxygen or by removing the heat from the fire. Fire extinguishers are used to douse the fire by discharging water to remove heat or by discharging chemicals like carbon dioxide to cut off oxygen.
Do you know what people with the job of putting out fires called?