Fire has been around for thousands of years and has played a many role in our society. Fire has been around since before humans were born, but it was humans that controlled the power of fire for heat, light, tools, food and protection. Fire is unlike water or air in that it is not a form of matter (made of atoms) but rather a chemical reaction. Fire has helped humans and their development in many ways but it can also destroy houses, entire forests, and lives.
Fire develops due to the rapid oxidation of a particular material (highly flammable or combustible) through the chemical process of combustion. Flammable compounds often contain carbon and hydrogen that will recombine with oxygen to develop carbon dioxide, water and other gases. During the combustion process heat, light, and various reaction products, that also releases energy. A chain reaction develops during these processes and may commonly be referred to as a fire tetrahedron (the big 4!). Fire cannot exist without all elements; heat, oxygen, fuel combined to form the chain reaction; and at the right proportions. A fire can be put out if one of the four elements is taken away.
The flames of a fire are the most visible aspect of fire that provides heat and light. Fire flames can be different colors and temperatures depending on what is being burned. Flames form because of a reaction of gases and solids that in turn emit various types of light. Flames can emit infrared, and even ultraviolet light.
Different flame colors also determine its temperature. A cigarette that is burning slowly can be as much as 750��! That is more than enough to boil water and skin! People usually see that flames are a yellow-orange color. But flames contain many different colors depending on what is being burned, what chemicals are involved and temperature of the environment the fire is in. For example, during a forest fire most of the burning is occurring near the ground so the flames appear white and have the highest temperature. The flame will gradually go from yellow to orange to red, which will be the coolest part of the flame. Cool as in hundreds of degrees less than the white part of the flame but still hundreds of degrees.
The fossil record of fire was established some four hundred and seventy million years ago in the Middle Ordovician period. The concentration of oxygen in the atmosphere rose above 13 percent, raising the possibility of wildfires. Wildfires were first recorded over 420 million years ago by ���charcoalified� plants from the Late Silurian fossil record. The extensive growth of grasses 6-7 million years ago plus the higher oxygen levels helped to make more wildfires that could be spread more easily than before.
Fire is used to help people to stay warm, cook food, and also scare away enemies or animals. There is evidence that fire was used to cook food over 1.9 million years ago. Some 50,000 to 100,000 years ago, people began using fire in a more controlled manner. People were starting to use fire as a tool for farming, fuel and even as a weapon.
In the last few centuries, fire was first used in internal combustion engines, power stations, and warfare as thermal weapons. Fire was also used in wars, leading to the invention of bombs. Now fossil fuels such as coal, natural gas, and petroleum are used in power plants to produce power, which is converted to electricity. About 80 percent of the world�۪s total power comes from fossil fuels. Fire is also used to heat water, drive turbines, and create steam.
Major Fires in History
The Great Chicago Fire
The Great Chicago Fire is considered one of the major fires of the past 100 years. It occurred in October 1871 in the dry season for Chicago. The fire started in all the wooden buildings and quickly spread, killing almost 300 people and destroying millions of dollars�۪ worth of property, including 17,000 structures.
San Francisco Earthquake Fire
The San Francisco Earthquake Fire started on the morning of April 18, 1906. As a result of an earthquake, a lamp and a stove overturned and a fire was started. It destroyed the city�۪s water main, which made it difficult for fire fighters to stop the blaze. The fire lasted for 3 days, killing 3,000 individuals.
Triangle Factory Fire
In New York City a fire broke out at the Triangle Shirtwaist Factory on the 25th of March in 1911. This was the worst industrial disaster in all of New York�۪s history until September 11th. One hundred and forty-six workers died from the fire or from jumping in order to escape the fire. The stairways and exits were locked so the workers were unable to escape the fire. This tragic fire led to changes in labor codes and fire safety in New York State that eventually spread throughout the whole country. Fire extinguishers, fire exits, and escape plans are common in workplaces today around the country.
Protection and Prevention
Fire fighters are trained people who help to control and put out fires. They will often use a large hose from a fire truck and hook it up to a fire hydrant or another water source to fight the fire. Fire prevention is important for everyone, especially children, in order to understand the dangers of fire and what to do in case of a fire. Many large buildings, offices and schools regularly conduct fire drills to prepare for the dangers of fire. Building codes help to ensure fire protection and minimize damage from a fire. Many buildings have fire sprinklers that are in the ceilings to help put out a fire that triggers a fire alarm. People with homes should have their own fire escape plan along with fire alarms and a fire extinguisher in case of a fire.
Various restoration techniques are used to recover the charred buildings from fire damage. Fire and Water Restoration professionals and companies are involved in the restoration process. These professionals are trained to restore buildings in the safest way possible.
Here are some great resources for teachers to use with lessons for teaching students about fires: