Think light bulb and you think of Thomas Edison, right? Well, two Canadians patented the light bulb in Canada in 1875. Henry Woodward and Matthew Evans were working on the same idea as Edison, although who got there first is still a matter of debate. We do know that Thomas Edison bought the rights to their patent. Edison successfully demonstrated the light bulb in 1879 and barely anyone remembers Woodward or Evans.

To keep light bulbs running, you need electricity. In many parts of Canada that's accomplished by hydro-electric dams that use falling water to drive turbines that spin generators. Here's how you can make your own turbine.

• Scissors
• 2L plastic drink bottle
• Pencil
• Two wide drinking straws
• Duct tape
• Thin string
• Water

1. 1. Cut off the top of the bottle and using the pencil, poke four holes around its base, but not directly on the bottom.
2. 2. Cut the straws in half and push them through the holes. They should be sticking out at an angle. The duct tape can be used to hold the straws in place.
3. 3. Poke three equi-distant holes around the top of the bottle and a string through each hole. Each string should be the same length. Then join the three strings to one long piece of string.
4. 4. If you're inside, hold the "turbine" over the bathtub, or go outside. Fill the bottle with water. It will squirt through the straws, and the bottle will spin.

Hydroelectric dams are built in areas where large reservoirs of water can be created. The dam has channels that lead to the turbines. When water is allowed to enter the channels, the turbines spin (just like yours did). Spinning turbines drive an electric generator which transforms the mechanical energy into electrical energy. The word turbine comes from the Latin turbot, meaning whirling object.