Investigating fire – introduction
We often hear about destructive fires in the media. We know that fire is dangerous and can cause severe damage and destruction and, at times, death. Since our earliest days, humans have sought to find out what fire is, how it starts and what keeps it going.
Fire experiment
Fire is a chemical reaction between oxygen in the atmosphere and some sort of fuel.
Sometimes we might think that fire is a living thing! It moves, ‘eats’ things and seems to breathe. The ancient Greeks thought it was one of four major elements, along with water, earth and air. They could feel, see and smell fire just like they could the earth, water and air, but fire is something completely different. Earth, water and air are all matter – they are made up of billions of atoms. Fire is not matter at all, and it is not a living thing. It’s the visible effect of a chemical reaction between oxygen in the atmosphere and some sort of fuel.
It is important to understand this chemical reaction and how it happens. This helps us to know how to prevent and manage fire disasters.
Ballantynes fire in 1947
The Ballantynes fire in Christchurch in 1947 is considered the worst fire in New Zealand history. It resulted in the deaths of 41 people.
Throughout New Zealand’s history, there have been many kinds of destructive fires. The Ballantynes department store fire in Christchurch in 1947 was the worst in New Zealand’s history – 41 people died. Other fires have included the destruction of houses, factories, storehouses, shops, land and bush (wildfires).
Meet the scientists
Scientists are continually researching for ways to manage fire, reduce its destructiveness or even prevent it from happening. Meet some New Zealand scientists and find out about the work they do.
Fire engineers Charley Fleischmann and Mike Spearpoint are trying to slow how quickly flammable items like furniture burn, through the use of chemical fire retardants. They are also interested in how people behave in a fire emergency. In addition, Mike also has a long-term project to test the performance of smoke alarm batteries. Find out more about heat and smoke detectors.
Grant Pearce and Lisa Langer are scientists at Scion. Together with Stuart Anderson, the trio research fire behaviour in the outdoors and how to manage this risk. Part of their work investigates the public’s perception of fire danger.
Tim Curran, Sarah Wyse and George Parry research the impacts of invasive weeds and introduced plants on wildfires. They’re testing plant species to use as ‘green firebreaks’ – strips of vegetation made up of plants with low flammability.
PhD student Mun Kit Cheong used computational modelling to help predict what might happen if a truck catches fire in a tunnel.
Modelling a fire in a tunnel
In this video clip, Dr Mike Spearpoint from the University of Canterbury talks about using computational modelling to predict fire behaviour – what might happen if a truck caught fire in a tunnel?
Points of interest
• What are some of the variables that would need to be incorporated into the model?
• What does the model allow the scientists to do?
• Why are scientists concerned with fires in tunnels?
Key science concepts
Fire, as a context for learning, covers key science concepts in chemistry. The article What is fire? explores the fire triangle. What is smoke? explains incomplete combustion and the dangers that smoke presents. Heat energy looks at heat transfer – convection, conduction and radiation. Fire behaviour explores the variables that influence fire.
Smoke
Smoke is a collection of tiny unburnt particles – very small carbon particles and tiny droplets of tar.
Take up the challenge
There are a number of activities that support student learning. Hands-on activities include:
Drama in the microworld – using drama to model atoms, molecules, heat transfer and combustion.
Light a candle – observe and investigate a candle flame and the process of burning.
The great candle experiment – the oft-used inverted jar in a saucer of water but without the common misconceptions.
Putting out the fire – investigate ways of extinguishing fire, using knowledge of the fire triangle and fire chemistry.
The flying teabag – investigating convection.
Exploding flour – observing combustion.
A candle's flame
Observe the various parts of a candle's flame and start to develop ideas about the combustion process.
Literacy-based activites include:
Fire risk assessment – use of an interactive to identify and define rural fire risks.
Fire safety – using scenarios involving fire risks and safety plans.
Fire in Antarctica – a literacy activity using an online article.
Ethics in fire science – develop critical thinking skills through ethical discussions.
Teacher resources include Alternative conceptions about fire and Fire – unit plan. Read about how two year 7–8 teachers used these fire resources to teach a cross-curricular unit combining science, English and ethics.
Across our year 7/8 classes, we make considerable use of the Science Learning Hub. With the Fire resources, we use a predict, observe, explain format - prefaced with the question, 'What makes science, science?' The favourite activities are Exploding flour and The great candle experiment.
Tony Roberts, teacher
Wildfires – what are they? What causes them? How do wildfires impact us and are they affected by the climate? Find out the answers in this Connected article.
Question bank
The Investigating fire – question bank provides a list of questions about fire and places where their answers can be found. The questions support an inquiry approach.
Key terms
For explanations of key concepts, see Investigating fire – key terms.
Timeline
Explore the timeline to look at some of the events and disasters relating to fire and how humans have learnt to manage this chemical reaction.
Nature of science
Loss of life and property in fire disasters has prompted scientists to study fire and fire behaviour in both structural and rural fires. It has only been since the early 1990s that fire research has developed in New Zealand. Organisations involved with fire research collaborate with each other and work with fire science organisations internationally, combining ideas and finances to provide more substantial work.
Useful link
In this Radio NZ Our Changing World article and podcast find out how New Zealand scientists, including Lisa and Grant, are working to improve the modelling of wildfires, and how Mātauranga Māori can be harnessed to reduce the risk of wildfire.
