It’s that time of year again, when we light up the barbeques and fireworks to celebrate another fantastic July 4th, with this year being America’s 247th birthday since the signing of the Declaration of Independence. As we watch the glorious light shows and explosions followed by the “Oooohs” and “Aaaahs”, it’s not uncommon to catch ourselves wondering how fireworks and firework shows work.
For instance, what are the specific chemical reactions that are responsible for these breathtaking light shows, and what steps are taken to make firework shows happen in the first place? Here, we will discuss how fireworks work and the behind-the-scenes logistics, which will give you some insight into what’s going on to make these spectacular light shows.
The primary ingredient in fireworks is black powder, also known as gunpowder, with the earliest usage of gunpowder being in 9th century China. For fireworks, the black powder is broken down into small pellets called stars, which ignite when lit. But what gives fireworks their breathtaking visuals are the plethora of colors, which are created through a variety of metals or chemicals. For example, red is produced from Strontium (Sr), yellow is produced from Sodium (Na), green is produced from Barium (Ba), blue is produced from Copper (Cu), orange is produced from a combination of Strontium (Sr) and Sodium (Na), purple is produced from a combination of Strontium (Sr) and Copper (Cu), and the various greys and whites are produced from a triple-combination of Titanium (Ti), Magnesium (Mg), and Zirconium (Zr).
The actual firework show involves launching a shell into the air from one ignition, where a second ignition causes the explosion in the sky that we observe as the final product. While an average firework show lasts approximately 20 minutes, the preparation for each show takes several days to weeks, as trained pyrotechnicians must adhere to strict guidelines outlined by the United States Department of Labor to ensure the safety for both the workers and viewing public down to the smallest of details. This includes a series of checklists to include meticulous inspections, handling procedures, and cleanup procedures. The trained experts also get the timing down, either with the aid of computers or an expert pushing the buttons for each launch, to ensure everything launches without a hitch.
This hopefully offered some insight into the chemistry and logistics of firework shows that you can enjoy while celebrating this year’s July 4th festivities. Stay safe, stay alert, and remember there’s always more going on behind-the-scenes than meets the eye!
Sources: Wikipedia, Library of Congress, United States Geological Survey, Geology.com, United Stated Department of Labor
As always, keep doing science & keep looking up!
