We are used to thinking that it takes a lot of energy to produce light. This time, we will see that even a small amount of the right kind of energy can give us some light.
This experiment will not work with the incandescent bulbs commonly used in lamps. They have a thin wire, called a filament, which has to get hot enough to glow to give you some light. That takes quite a bit of energy, and much of it is lost as heat.
The fluorescent bulb does not have a filament. Instead, the air has been removed and replaced with mercury vapor and other gases at low pressure. When high voltage electricity moves through a gas, it can change the gas into plasma, the fourth state of matter. We have all learned about solids, liquids, and gases, but plasma, the fourth state is by far the most abundant kind of matter in the universe. Plasma is like a gas that has had its electrons ripped away. The atoms are surrounded by a sea of electrons, making plasmas very good conductors of electricity. When you consider that stars (as well as flames, electric sparks, and the glow in a neon light) are made up of plasma, you can see that it is very abundant, making up over 98% of all the known matter in the universe.