FIREWORKS: Judging by the pops and crackles we’ve been hearing at night, the season of fireworks has begun.

A bit of history: The Chinese were the first to create fireworks — although the original intention was to scare away large mountain men. Chinese people were writing on green stalks of bamboo and heating them in the fire, when they realized that heating them for a longer period caused a loud noise and that noise scared men who happened to be large and mountain-dwelling. Fireworks were also credited with scaring away evil spirits.

Sometime between 600 and 900 C.E., Chinese alchemists discovered gunpowder by accidentally mixing saltpeter, sulfur and charcoal. This discovery was partnered with bamboo stalks, and with the mixture in the stalks, a form of sparkler. From there, military minds went to work and began to adjust the mixture for use in weaponry.

Italy took the firework a step further, creating a shell and also making the fireworks colorful.

Organic salt is layered with the oxidizer, potassium percholorate, to create the whistling sound that people associate with fireworks because each layer burns by itself. Flakes of aluminum or iron can be added to create sizzling, while the loud bangs come from titanium powder (which also provides white sparks).

It is not possible to recycle fireworks. Instead, the discarded shells should be soaked in water before they are thrown in the garbage. If you have fireworks that are unused and want to dispose of them, it is wise to call your local waste department to see what the preferred procedure is for your area.

It is important to note here that, while popular, fireworks are not fun for everyone. Veterans can suffer episodes of PTSD, animals can have adverse reactions and birds can become disoriented and get injured flying into things.

Be considerate with your celebrations.