How Fire Works
Fire is a chemical reaction that turns fuel and oxygen into energy in the form of hot gases. These gases spread outward from the center of the flame and heat the surrounding air, which expands outward as well. This expansion gives the flame its characteristic shape and appearance. Fire burns hot and fast, so it can damage buildings and kill people. It can also destroy plant life and pollute the air.
Fire has many uses, and some humans use it intentionally to achieve certain results. For example, a fire in a power station converts coal into electricity. Other times, it is used to help plants grow, or in cooking and heating homes. It can even be useful in cleaning up the environment by destroying diseased trees and shrubs.
In addition to providing warmth and cooking food, it’s a source of light, which allows us to see in the dark. Some types of fire give off radiant heat, which warms objects that its rays touch. Other types of heat move through the air as convection, which is how your clothes feel when you sit in front of a fireplace or stove.
The way that fire burns is complicated and involves many steps. First, the flammable material (wood or gasoline) must be heated to its ignition temperature. This happens when it comes into contact with something that heats it up, such as a match, concentrated sunlight or friction.
Once a fire has started, it can be sustained by a process called rapid oxidation. This happens when the molecular structure of the fuel breaks down and releases a lot of energy. Then the atoms of the fuel fuse together with oxygen molecules from the air to create new molecules—water and carbon dioxide, for instance. The new molecules release more energy, which causes the fuel to keep igniting. The cycle continues until the fuel runs out or the chemical reaction slows down.
A good way to understand how a fire works is to imagine what it would look like in space. The hot gases in a flame are much less dense than the surrounding air, so they rise up and expand outward, creating the impression of a solid flame. On Earth, gravity helps this process along, but if we were in microgravity, a flame would spread outward and point downward instead of upward.
It is important to be prepared for a wildfire in your area, and make sure you take precautions to protect yourself and your property. Make sure your gas meter and propane tank are secured, and don’t use anything that could spark or explode. If you hear or see an evacuation order, follow it immediately. Check for smoldering debris and report any damaged utility poles or lines to the proper authorities. Make sure your family has a fire escape plan, and practice it often. Also, remember that fire can be dangerous to animals as well. So be sure to secure your pets and keep them inside if possible.