Fireworks how they work

Fireworks how they work

Fireworks have a history going back thousands of years. It is generally believed that they were accidentally discovered by a cook in China using commonly available kitchen ingredients. The ingredients that went into the first fireworks were charcoal, potassium nitrate and sulphur.

Fireworks how they work

Fireworks have a history going back thousands of years. It is generally believed that they were accidentally discovered by a cook in China using commonly available kitchen ingredients. The ingredients that went into the first fireworks were charcoal, potassium nitrate and sulphur. These ingredients along with some additions are used in fireworks, firecrackers and sparklers to this day.

What goes into fireworks

A firecracker is made by adding these ingredients into a tight paper tube, along with a fuse that is inserted into the tube to help ignite the mixture. A firecracker may also contain aluminium to add brightness to the explosion. A sparkler burns for a longer time giving out bright colours and a shower of sparks that can be varied by changing the composition. A sparkler contains the same basic ingredients – charcoal, potassium nitrate and sulphur – but they are mixed in a different proportion than that used in a firecracker so that they burn more slowly. In addition, a binder such as starch or sugar is added to form a slurry that is poured into a tube or coated on a wire. Once this dries, the sparkler is ready to burn. To create bright sparks, aluminium, zinc, magnesium or steel dust is added. These materials heat up easily to become incandescent adding to the brightness. The sparklers get their variety of colours from chemicals added for this purpose. As you can see, fireworks can be made to burn and give off a variety of sparks and colours by burning slowly, or to explode suddenly, through the manipulation of the mixture and the addition of appropriate ingredients. Now let’s see how they can be made to generate a variety of fireworks displays that we commonly see.

Aerial fireworks

Aerial fireworks are among the most common types of fireworks that we see at any fireworks display. These shoot up to a considerable height before exploding into a shower of sparkling colours. How do they first rise to such a height and then explode? Basically, aerial fireworks have two components – a shell and a mortar. The shell is the part of fireworks that goes up into the sky and bursts into a display of colourful sparks. The shells of fireworks contain four ingredients – a container, stars, a charge to enable the bursting, and a fuse. The container is usually a spherical or cylindrical item made of paper or board and string. This container is filled with the stars and the bursting charge. The stars are cylindrical, spherical or cubical pieces that burst into the colours that you see in a fireworks display. They are made from the ingredients that go into a sparkler so that they burn with an incandescent light, and depending on the chemicals added, give out different colours. The bursting charge is placed at the centre of the shell and is ignited by a fuse, which also forms part of the shell. The other component of the aerial fireworks, namely the mortar, is what launches the shell into the sky. The mortar is made up of a small metal pipe that is filled with the exploding charge and a fuse. When the fuse is lit, it ignites the charge and causes it to explode, launching the shell into the space above. At the same time, it also ignites the fuse in the shell, which ignites the bursting charge in the shell after the lapse of a suitable interval. By the time this happens, the shell has reached a respectable height, and that is how you see the wonderful display at a great height in the sky.

Adding sophistication

This process can be extended to multiple levels by including more than one shell in fireworks. Subsequent shells can be ignited by each shell as it receives the ignition, causing a time delay between the bursting of different shells. This results in a complicated array of multiple shells that seem to burst one after the other in the sky. This idea can be further extended to create patterns in the sky by arranging the shells in a carefully planned manner and planning their ignition at the right time. This can be used to create a variety of visual effects that result from different shapes, leading to beautiful patterns and captivating fireworks displays.