Notes from Professor Boggs:
Another big subject for a song! This will hopefully raise more questions than it will answer, but we cover some basics. Electric potential (voltage) versus kinetic flow (current) is contrasted. Conductors and insulators are explained, and how they can be used to direct current. The link between electricity and magnetism is touched on, and the concept of generating an electromagnetic wave using an alternating current. Finally, we (briefly) explore the computer with a cloth/stitching metaphor. You might consider having students or teams take a single verse and explore its concepts in more detail.
Where ya gonna see… E-lectricity
Where ya gonna see the spark?
From a doorknob tickle on a winter’s day
To the fire of lightning in the dark
Stack up some electrons on one side of a wall
They leave behind some positive holes
Plus and minus ions – they are always tryin
To jump across and balance out the difference in the poles
Now electrons like to travel through conductive things
An insulator keeps them where they are
If you know which way they’re flowin’ you can get a circuit goin’
You can run a fan or power an electric guitar…
If you spin a magnet near a copper wire
The electrons start to dancing back and forth
If you send electric power through a coil around a tower
You will find you have a magnet with a south and north
Jiggle some electrons in a piece of copper wire
You’ll be sending out a wave, you see
And over at a distance, something with a low resistance
Will pick it up and turn it into electricity
Look in your computer
It’s a million little switches
Patterns of electrons like a
Fabric and its stitches
Pushin’ those electrons through
A maze that’s never seen
But finally it lights up all the
Pixels on your screen
We can never really “see” electricity! Maybe the closest we come is to see the light generated by a spark, when an electric charge builds up and jumps through air (an insulator). The force that gives you the little “ouch” from built-up ions in your body discharging onto a doorknob – that’s the same force in a lightning strike. Just more ions!
Protons and electrons like to be closely paired up. But sometimes electrons can “roam free” and they leave positive-charged ions behind. This builds up what we call “electrical potential” or “charge” measured in Volts. The electrons want to get back to the protons! This is “potential energy” just like a heavy object uphill – ready to do work.
Electrons travel freely through most metals because of the loose bonding. Rubber, plastic, air, etc. are insulators, “walls” to electricity. Knowing this, we can engrave metal “traces” onto a plastic board and direct the electron flow (current, in amperes) where we want it to go. Or use wires, the old-fashioned way! Electron flow is “kinetic” energy and can do work, such as running a motor, generating heat and light, and so on.
Michael Faraday discovered that magnetism and electricity were closely related...