The Science of Fire

Fire is a display of heat and light that occurs when a combustible material, such as wood or paper, is exposed to the combination of heat, oxygen and energy (often in the form of electricity). The chemical reaction that produces fire is called combustion. Combustion changes the chemical composition of the starting material and produces different product molecules — including water and carbon dioxide — that are not the same as the original fuel. This is an exothermic process, meaning it releases more energy than is consumed to start and sustain the reaction.

While early chemists once believed that fire was caused by the liberation of a mysterious substance known as phlogiston, the science behind fire has changed dramatically over time. Today, scientists know that the flames you see at a campfire are the result of a simple chemical reaction. The same type of reaction occurs when you leave a cut apple on your counter, when silver tarnishes or an iron nail rusts.

During the chemical reaction that creates flames, the product molecules release a large amount of heat. This energy can then cause other chemical reactions, such as erosion or chemical weathering. For instance, erosion of soil can loosen rocks and debris, which can then be carried away by wind. Chemical weathering can also reshape the surface of a building, creating cracks or crevices. This may lead to the collapse of the structure and injuries to people or animals living inside the building.

Humans have used fire for thousands of years, both for cooking and for creating a variety of materials. Many modern buildings, such as homes and office buildings, are designed with fire-resistant features, including firewalls and other barriers to prevent the spread of fire from one room to another. Other modern uses for fire include heating, electrical generation, and drying or sterilizing items.

When a wildfire approaches your home, follow the instructions of local officials to prepare for an evacuation. Make sure your car has a full tank of gas and that you have alternate routes if the need to evacuate arises. Check your house to be sure it is safe, closing all windows and doors, turning off the air conditioner and other systems that circulate air, and making sure your pets are secure. If you are able to stay at home, turn off any water faucets and be sure the water heater is turned off. Keep your distance from a wildfire, as smoke and dust can be harmful to you, your family and your pets.

In some areas, fires are deliberately set and regulated for safety reasons. These types of fires are called controlled burns and they can be important to ecosystems by clearing out brush and undergrowth that is threatening the health of natural vegetation. In addition, wildlife species such as whitetail deer thrive in habitats that have recently experienced a controlled burn because they are able to obtain food from vegetation that would otherwise be out of reach.