Fire is one of the four classical elements and is central to many cultures’ mythology. It’s also used for cooking, light, warmth and signalling, as well as for smelting and forging and to destroy waste. In modern times it is used for power generation, e.g. in coal or oil-fired power stations. It is also used for generating heat energy to dry clothes and cook food.
The energy released by burning fuel can be converted to electricity through a thermal generator such as a steam turbine, producing mechanical work. It can also be used to produce heat directly by combustion, in internal combustion engines. The energy from a fire is often absorbed by the surrounding environment in the form of heat or vibrations (sound). Fire can also be used to create energy through evaporation, where water absorbs the energy of the flame and releases it as a cooler substance such as vapour.
There are four things needed for fire to happen: oxygen, fuel, chemical reaction and heat. This is known as the fire triangle. Oxygen and fuel must be combined with the right amount of heat to cause a chemical reaction called combustion. When this happens, the atoms of the fuel rearrange themselves irreversibly and the resulting gases release heat. The reaction will continue as long as there is enough fuel, oxygen and heat. This is why it’s important to never leave candles unattended or keep them close to bed curtains, as this can lead to house fires.
A fire’s flame is formed by a series of gas molecules which are hotter than the air around them, so they expand and move upwards in the direction of lower pressure. This is why a fire typically appears to be pointed upwards. The hot gases are also much lighter than the air they are moving through, making them travel more quickly than a steady breeze. It is also the reason why it is so hard to stop a fire once it gets started.
Fire science is the branch of physical science which deals with fire behavior and dynamics. It includes research into the processes and physical properties of fire, such as its speed, shape and movement.
Fire is one of the world’s most useful and fascinating natural phenomena, but it can be dangerous if misused. The most common way that people die from fire is from smoke inhalation. A fire can also damage structures, and cause significant environmental problems. The causes of fires include lightning, human activity, arson and electrical failures. People can protect themselves by heeding evacuation orders and following simple safety precautions, such as not leaving candles lit or keeping them away from flammable items like blankets. People can also prevent house fires by keeping their doors and windows closed, making sure to check that they are closed properly before going to sleep. They can also install smoke alarms, place them near a working escape route and regularly test their batteries.