The science behind fireworks

The science behind fireworks

(WAFF) - Year after year, many of us head to area Fourth of July fireworks shows but we often take for gr anted the science behind the rocket's red, blue, or yellow flares.

The cause for that big, bright explosion of color actually starts at the molecular level.

Each element releases a different amount of energy, and this energy is what determines the color or wavelength of the light that is emitted.

The more energy that's released, the shorter the wavelength of light and the cooler color you'll see. For example, when a copper salt is heated it releases more energy and results in a cooler, blue color.

When a calcium salt is heated, it releases less energy and results in a warmer, more reddish color. Just like paints, secondary colors are made by mixing the ingredients of their primary-color relatives. A mixture of copper (blue) and strontium (red) makes purple.

The sights are incredible, but the loud booms are also all part of the experience.

That same release of energy causes the air to expand faster than the speed of sound, resulting in what many of us know to be a sonic boom. This is exactly why thunder is a result of lightning.

Fireworks, and thunder and loud booms on the Arsenal for that matter, can be louder when there are low clouds overhead, as clouds trap the sound towards the surface.

So why do we see the light before hearing the sound?

Think of a thunderstorm. You see lightning way before you ever hear thunder in most cases.

That's because the speed of light is 300 million meters per second, whereas the speed of sound is only 340 meters per second. That means that light travels 900,000 times faster than sound.

As you celebrate America's independence, just remember that a firework is more than meets the eye and ear.

Copyright 2016 WAFF. All rights reserved.