' Charge vs. Energy, or, "What is electricity, REALLY?"
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W. Beaty 1997

Here is the simple answer. There are two main things that flow along wires:

  • Electric Charge
  • Electric Energy
There are several other things that flow as well, but to keep it simple, we'll ignore them.

Because there are *two* things flowing, we cannot call them both by the name "electricity." And for this reason, we cannot ask "what is electricity?" (Which one are we asking about?!) So, instead we have to ask more specific questions, like these below:

  1. What is the stuff that flows through a light bulb and comes back out again through the other wire?
  2. What is the stuff that flows into a light bulb and gets changed entirely into light and heat?
The answer to question #1 is ELECTRIC CHARGE. Charge is a "stuff" that flows through lightbulbs, and it flows around a circuit. Normally no charge is lost during the operation of a circuit, and no charge is gained. Also, charge flows very slowly, and it can even stop flowing and just sit there inside the wires. In an AC circuit, charge does not flow forwards at all, instead it sits in one place and wiggles forwards and back.

The answer to question #2 is ELECTRICAL ENERGY. It's also called "electromagnetic energy". This energy is also like a "stuff" and it can flow from place to place. It always flows very fast; almost at the speed of light. It can be gained and lost from circuits, such as when a light bulb changes the flow of electrical energy into a flow of light and heat.

Here is a list of differences of these two kinds of "stuff":

Flows very slowly, and can even stop. ----- Always flows incredibly fast, almost at the speed of light.
The flow is called "electric current," measured in Amps. ----- The flow is called "electric power," measured in Watts.
Flows through light bulbs --- Consumed by light bulbs (and converted into light)
In AC cables, it wiggles back and forth --- In AC cables, it flows continuously forwards
Supplied by metals (and by all other conductors) --- Supplied by generators, batteries, etc.
It's a component of matter --- A form of energy
Doesn't usually leave a circuit. --- A "Source" injects it into a circuit, while a "load" removes it again.
Composed of movable charges from conductor atoms --- Composed of electromagnetic fields
Electrons and protons are particles of CHARGE --- Photons are particles of E.M. energy
Flows inside of wires --- Flows in the space adjacent to wires
Generators pump it through themselves --- Generators create it
Circular flow. It flows around and around the circuit, and never leaves it. --- One-way flow, from a "source" to a "load".
VISIBLE: it is the silvery part of a metal --- INVISIBLE: the EM energy can only be seen if you use iron filings, etc.
Measured in units called Coulombs --- Measured in units called Joules
Occurs naturally --- Produced and sold by electric companies
Scientists of old called it "electricity." --- Today, electric companies call it "electricity."


Still confused? Well, there's one way to connect all this stuff into a single coherent whole. Just realize that electrical energy is wave-energy, and charge is the "medium" for these energy-waves. Waves-versus-medium.

This idea becomes clearer in AC circuits, where the charge wiggles back-and-forth inside the wires, while the electrical energy zooms forward at the speed of light. (This is much like sound, where the air is wiggling forwards and back, yet the sound-waves move forward in one direction through the air.) If electrons inside metals were like air molecules, then electrical energy would be like sound waves! Well, approximately. Sorta. It's just an analogy.

Perhaps some pictures would help? Here are two diagrams below. More can be found at Where does the Energy flow?


CHARGE flows in a closed circle.
The flow is measured in Amperes
It flows inside the wires.
It's provided by the metal.
Batteries pump it through themselves.
None is created, none is ever lost.


ENERGY flows from the battery to the resistor.
The flow is measured in Watts
It flows in the space outside the wires.
It's made of invisible fields.
It's the same as light and radio, but lower in frequency.
Batteries create it. Electric heaters consume it.

Electric charge flows along wires. So does electromagnetic energy. If you ask "what is electricity", the answer is which one?


(Natural philoso-fiction?)

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