DIWALI

                                 DIWALI
According to belief, the sound of fire-crackers are an indication of the joy of the people living on earth, making the gods aware of their plentiful state. Still another possible reason has a more scientific basis: the fumes produced by the crackers kill a lot of insects and mosquitoes, found in plenty after the rains.

Diwali is associated with lights, sweets, and liveliness; especially lights. As, it is celebrated on the new-moon (Amavasya) night, lights and fireworks have a significant role to play in this festival. This is why, when we heard the name Diwali, the first impression that flashes through our minds is of multicolored and impressive fireworks, sprinkling various sorts of bright colored lights in the night sky. Although the tradition of fireworks on Diwali is not very old, still they have succeeded in becoming such a vital part of this festival that we can't even imagine a wonderful Diwali without them.
In Sivakasi the first fire works industry was started in the early 20th century. Having achieved a measure of success in Safety Matches, Colour Matches and Star Matches, Mr. A Shanmuga Nadar and Mr. Iya Nadar ventured upon the making of sparklers –then the most popular item in the Small Fireworks family, which were at the time imported from the UK and Germany.
Pyrotechnics is the science of using materials capable of undergoing self-contained and self-sustained exothermicchemical reactions for the production of heat, light, gas, smoke and/or sound. Pyrotechnics include not only the manufacture of fireworks but items such as safety matches, oxygen candles, explosive bolts and fasteners, components of the automotiveairbag and gas pressure blasting in mining, quarrying and demolition.
Individuals responsible for the safe storage, handling, and functioning of pyrotechnic devices are referred to aspyrotechnicians.
There are many varieties

Display pyrotechnics
Consumer pyrotechniques
Fireworks display

Fire works are used in many occasions in India -winning elections, winning cricket by the national team, and so on.

Pyrotechnics can be dangerous substances that must always be treated with the utmost respect and with the proper training. Due to the hazardous nature of these materials, precautions must always be taken to ensure the safety of all individuals in the vicinity of pyrotechnics. Despite all precautions, accidents and errors occur from time to time, which may result in property damage, injury and in severe cases loss of life. These incidents may be the result of poorly manufactured product, unexpected or unforeseen events, or in many cases, the result of operator error.

I don't believe in any scientific use of the fireworks.