It's New Year's Eve, which can mean only one thing. Fireworks.
Well, for some people anyway. Where I live the traditional New Year's fireworks have been postponed due to extreme fire risk.
While I understand that some people are disappointed by this, it doesn't bother me - I'm not that big a fan of fireworks anyway (I know, I know, I'm a total Grinch). They terrify our pets, disturb native wildlife, and generally cost an exorbitant amount - money that could perhaps be better spent on healthcare, education, social support services... but I digress.
Anyway, for those of you who will be enjoying some fireworks tonight, have you ever wondered what creates all those fantastic colours? It's all about the chemistry.
Fireworks are basically little rockets. Packed into those rockets are different metal elements or metal compounds. When heated these compounds emit different colours. Sodium salts, for example, are used to create brilliant gold sparkles. Magnesium gives off a bright white bang. If orange is more your colour, then calcium salts are what you'll enjoy.
Reds can be produced by lithium or strontium, while green is the result of burning barium. Blue is the trickiest. You need copper salts for blue, but they need to be at exactly the right temperature to emit a bright blue colour. If the explosion is too hot or too cold then then the colour will be washed out.
Other elements are added to fireworks to help with the special effects. Adding aluminium compounds helps to create a sparkler effect, while antimony gives more glitter.
Titanium will produce silver sparks, while some calcium can help to give deeper colours to fireworks. Adding zinc creates a great smoke show, and phosphorous is used for glow-in-the-dark effects. By choosing the right mix of compounds, and packing them together in the right way, pyrotechnicians can create an amazing range of effects.
But it's an art best left to the professionals. Many of the compounds used in fireworks are unstable and dangerous, and then of course there is all the black powder used as the propellant for launching them into the sky. Each year there are numerous injuries, and even deaths, when untrained people play around with lighting their own fireworks.
Whether your evening is full of fireworks, or like mine, a bit quieter, I wish you all the merriest New Year, as we send off 2019 with a bang.
Dr Mary McMillan is a lecturer at the School of Science and Technology, University of New England.