Burn Baby Burn

What is fire? To some people, fire is beautiful and incredible due to its random flickering beauty. To others is is feared, a force for destruction capable of consuming forests and the carbon based life which thrives on our planet. At risk of sounding like a pyromaniac my second post will be about this deceptively complicated process and the true nature of flames.

To understand fire first we have to understand what it means to burn. To burn or to combust is a chemical process which it is why so many things can burn as it is not limited specifically to wood or any other one material. Combustion is basically a high temperature chemical reaction between the reactant (the fuel) and an oxidant which is usually oxygen. This process produces oxidised products which form smoke, depending on the amount of oxygen available these may react further or just be comfortable in their own state.

The oxidisation reaction which occurs when fire burns is extremely exothermic which means that it gives out heat, this means that it transfers heat energy to other particles in the fuel, so they also break down. This means that fires are self sustaining and is why they grow out of control so easily, there is a surprising number of types of combustion, however they all work on this basic principle. 

Now for the flame.

When the molecules absorb energy this "excites" the electrons. This basically means that the move up a level or two. The flame itself comprises of an extremely hot gaseous mixture in which the electrons have been excited a considerable amount and as they drop down to their normal energy level they release bursts of electromagnetic radiation as visible light which is why flames can be different colours as the more excited the electrons are, the more energy they release and the bluer the flame is. 

The shape of a flame is caused by convection currents of soot and this also accounts for the changing colour as you go further out from the base. In minimal to zero gravity e.g. in space (right) flames are spherical as gravity plays a factor in the formation of convection currents.

And there you have it :) I hope you find this as interesting to read as i did to research and it really shows how much we have left to discover. As we probably know fire was the first chemical reaction man learned to control back when they needed a way to cook their mammoth steaks, and yet we are only now coming to terms with the complicated quantum mechanics which govern the way in which one of our most defining tools is made. Our universe is more vast and complicated than we will ever comprehend and it will forever inspire questions. Thanks for reading.