Pretty, Pretty, Bang, Bang

Dr Jackie Akhavan is a Senior Lecturer at Cranfield University in the Department of Environmental and Ordnance Systems. She began to supervise research in polymer bonded explosives and pyrotechnics and has developed the demonstration lecture from the results of her research. 

She started off explaining what a firework actually is and how the different parts are used to achieve the different effects that you see. This led onto how the various colours that you see in a firework are obtained. Red, green and yellow flames were formed from commercial manufactured pellets. We then moved onto a blue coloured flame, which is a far more difficult colour to achieve, due to the wavelength. 

She then explained the role of the rocket within the firework and how this is researched within an enclosed environment of a university laboratory. Inevitably this involved yet another demonstration. This led smoothly onto when you coil a tube you produce a Catherine wheel. It was explained that this causes its own problem and that they are notoriously unreliable. This was proved correct by the next demonstration, in which the Catherine wheel failed to work fully.

Jackie then discussed the cause of the Bang which is associated with virtually all fireworks that we use today. She compared the volume of a UK and Chinese banger.  

Recent developments into fireworks of the future allowed Jackie to show us a firework which has a controlled strobe effect, flashing on and off at timed intervals.  

Safety was paramount at all times, with safety screens separating the audience from the fireworks. The importance of the firework code was impressed upon us using vivid examples. The audience ranged from 11 through to 70 and all enjoyed the lecture, smoke and all and exited the hall with a better understanding of the chemistry which goes into the fireworks we take for granted every November.