At the night before Eid, takbeer night, children often play fireworks. This has become a culture in Indonesia. Some fireworks are thrown and some are held by hand. Fireworks that are held by hand are usually in the form of powder dough attached to a metal wire. The length is various, from about 10 cm to more than 50 cm.
There was an interesting thing when we playes fireworks on the takbeer night of 2014. When a 40 cm-length firework was accidentally tilted when burned, it appeared that the shape of the final shape of the left wire was depending on the angle when burning. This means that there is a physical mechanism behind this phenomenon. We then formulated the physics model (theory) to explain that observation. Fireworks burning experiments at various angles were also carried out. We obtained the experiment results were in accordance with the model predictions. Those results have been published in the European Journal of Physics with the title “Bending of sparklers”
Image source: aditsuandana.wordpress.com