What makes the Super Sparker spark?
When you rub Styrofoam on your hair, you pull electrons
off your hair and pile them up on the Styrofoam. When you put an aluminum
pie tin on the Styrofoam, the electrons on the Styrofoam pull on the electrons.
Some of the electrons in metals are free electrons --they can move
around inside the metal. These free electrons try to move as far away from
the Styrofoam as they can. When you touch the pie tin, those free electrons
leap to your hand, making a spark.
After the electrons jump to your hand, the pie tin is short
some electrons. When you lift the pie tin away from the Styrofoam plate,
you've got a pie tin that attracts any and all nearby electrons. If you
hold your finger close to the metal, electrons jump from your finger back
to the pie tin, making another spark. When you put the pie tin back on the
Styrofoam plate, you start the whole process over again.
What does all this have to do with lightning?
The lightning bolt is a dramatic example of static electricity
in action. You see lightning when a spark of moving electrons
races up or down between a cloud and the ground (or between two
clouds). The moving electrons bump into air molecules along the
way, heating them to a temperature five times hotter than the
surface of the sun. This hot air expands as a supersonic shock
wave, which you hear as thunder.