http://www.youtube.com/watch?v=SifcDzDcfkc Fire breathing is not a hobby I've ever attempted to take up and that's probably for the best - both for my own wellbeing and for that of those around me. However, I did recently have the pleasure of meeting Tim Cockerill - someone who has taken this up as a hobby and luckily is rather good at it. Actually, he's 'Doctor' Tim Cockerill, because he's also an entomologist, that's correct, a fire breathing entomologist!
Anyway, we decided to make a short and simple film exploring the science behind his act, also known as the 'human volcano' - essentially a film that would look at the process of combustion and how this relates to the methodology of fire breathing.
We also made good use of our GoPro and strapped it to his head to get some awesome point of view fire breathing shots - you can see these in full below:
There was a bit of a struggle in deciding how to explain burning, we wanted to avoid the use of the 'fire triangle' - (often taught at school) because we didn't want to make something resembling a dry educational film, but at the same time we didn't want to get too bogged down in the chemistry of oxygen and how this relates to its reactivity.
In the end we settled for explaining what 'burning' really means - I think the word often leads us away from understanding / remembering what it means to burn something. Essentially it's just the name we give to the chemical reaction between oxygen and a fuel, a reaction occurs and new products are formed (and energy is given off in the form of light and heat). In this case the fuel Tim is using is a hydrocarbon which he reacts with the oxygen in the air to form carbon dioxide and water (and the fire ball!)
So yes, we haven't gone into the chemistry of oxygen and why it's so reactive - but I think our explanation is sufficient for the purpose of the film - we wanted to attract people with the thrills of fire breathing and use this as an in-route to explain some of the underlying chemical principles.
I think it's really easy to forget simple things like this and we often assume we know what we mean when we use an everyday term like burning. It's only when someone calls you out and asks you to explain what's going on that we may stumble and realise we don't actually know as much as we assumed we did. The YouTube Channel Veritasium does a great job at highlighting common shortcomings and misconceptions when it comes to explaining everyday phenomena (watch the video 'Misconceptions About Temperature').