Fireworks Above Bark Lake, Ontario
July 01, 2016
The photo montage above shows fireworks over Bark Lake, Ontario as viewed on July 2, 2015. Fireworks are missiles designed to explode in controlled bursts of sound and bright colors. There are five essential parts to fireworks – stick, fuse, charge, effect, and head. Some of the chemical energy locked inside fireworks launched into the sky is converted into four kinds of energy; heat, light, sound, and kinetic energy. Fireworks are powered the same way space rockets are – by Newton’s third law of motion. Hot exhaust gases fire backward creating an equal and opposite reaction forcing the firework to shoot into the air.
When fireworks explode, a number of chemical reactions take place at the same time or in rapid sequence, but it's heat that provides the activation energy to cause the packed compounds to combust with oxygen in the air, converting them into other chemicals. You may remember from a high school science class that when you burn metals in a Bunsen burner, they glow with intense colors. In essence, that’s what is happening when we watch fireworks.
- Strontium and lithium salts produce red colors
- Calcium salts produce orange
- Sodium compounds produce yellow
- Barium compounds produce green
- Copper compounds produce blue
- Incandescence of iron (with carbon) produce gold
- Mixture of strontium (red) and copper (blue) compounds produce purple
Note that both Venus and Jupiter joined this fireworks display. They can be seen in a number of the pictures -- look on the left-hand side just above the cloud line. These fireworks were originally scheduled for July 1 to celebrate Canadian Independence Day, but due to strong winds they were postponed until July 2.
Photo Details: Canon T3i camera on a tripod. I used a remote shutter release and a one- to two-second shutter speed; ISO 200; f/5.6 at 18 mm.