Fire is an ancient technology that has helped shape human evolution. Our ancestors used fire for safety, cooking and preserving food. They gathered around a flickering fire to share stories, pass on cultural knowledge and build community.

Today, fire is an important industrial tool. It remains woven into our daily lives and rituals (think blowing out candles on your birthday cake). As it did millions of years ago, fire can shape our landscapes, having the power to both devastate and rejuvenate entire ecosystems.

Fire is so familiar, and yet it can be hard to define. What actually is fire?

Let’s begin with a question that’s a little easier to answer.

To light a fire we need three things: fuel (something to burn), oxygen and an initial spark or heat source. This is known as the fire triangle, but you could also call the fuel and oxygen “reactants” and the initial heat the “activation energy”.

For a bushfire, organic matter (such as wood) provides the fuel. Oxygen is available in the air, and the activation energy could come from a range of sources, such as

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