Many encyclopedias, dictionaries, and textbooks contain very clear statements about the nature of Electricity. They say this:
- Electricity is a type of energy.
- Electric current is a flow of energy.The above statements are wrong. Yes, electrical energy does exist. However, this energy cannot be called "Electricity," since Coulombs of electricity are very different from Joules of electromagnetic energy. Energy and charge are two different things, so they cannot both be the electricity. It's not too difficult to demonstrate the mistake. Below is a collection of simple facts which show that Electricity, the stuff that flows within copper wires, is not form of energy.
- In a simple electric circuit, the electricity flows slowly in a complete circle, while the energy moves differently. The electrical energy flows rapidly across the circuit, going from the source to the load but not returning. The energy does not follow the circular flow of electricity; electricity and electrical energy are two different things. No charges of electricity are gained or lost as the charges circulate within the wires, yet batteries create electrical energy from chemical energy, and light bulbs destroy[1] the electrical energy as they convert it into light. Electrical energy takes a rapid one-way path from battery to bulb and then leaves the circuit as light, while electricity flows slowly around (and around and around) a closed-loop path and none is lost.
- If electricity is like water inside a pipe, that's the Hydraulic Analogy. But water is not a form of energy. In hydraulics, the energy travels instantly to all parts of the fluid loop, while the fluid itself moves slowly. Two things are flowing through the pipe: slow fluid and fast energy. Or, suppose that electricity is like a row of billiard balls inside a tube. When you push one billiard ball of electricity into one end, all the balls move forward. The energy travels almost instantly along the column of electricity-balls, while the electricity itself moves slowly. The balls aren't made of energy. And two things are moving through that tube: slow electricity and fast energy.
- In a lightbulb, charges of electricity flow through the filament and back out again. None are lost. This electricity enters the light bulb through one wire, and the same amount of electricity leaves through the other wire. Yet the energy doesn't act like this at all; it doesn't flow through. Instad the light bulb uses up the electric energy: the electrical energy flows one-way: into the bulb via both wires and it's all transformed into heat and light. The electrical energy doesn't come back out through the second wire and return to the battery. Two things are flowing: electricity flows in a closed loop, while energy is flowing one-way from source to load.
- In an AC system, the charges of electricity move back and forth
over a distance shorter than a ten-thousandth of a millimeter. In other
words, they sit inside the wires and
vibrate. That's what "Alternating Current" or AC is all about. The
electricity does not move forward at all (if it did, that would be
a direct current or "DC.") Yet while these charges of electricity are
wiggling back and forth, at the very same time the electrical energy moves
forward rapidly. Only the electricity "alternates." The electrical
energy does not; the energy flows continuously forwards as waves.
If this is confusing, consider sound waves which move through collections of air molecules. Electricity is like the air which is vibrating, while the electrical energy is like sound waves which fly through the air. Sound and air are two different things, just as energy and electricity are two different things.
Before I go too far with this, I must admit that I am playing a small trick with words. In the above statements, I am using the word "electricity" in the way scientists have used it since Electricity was first investigated. I am using the word "electricity" to name the stuff that flows inside the wires; where a quantity of electrons is a quantity of electricity, and where a flow of electricity is called "an electric current."
Why is this a trick? It's a trick because most people use the word "electricity" in a totally different way. They begin by defining the word "electricity" to mean electrical energy! Electric companies do this (think of kilowatt-hours of electricity.) So do the science textbooks written for grades K-6. So do many dictionaries and encyclopedias. This causes endless confusion. Physicists try to tell us that the charges of electricity are not energy, and that a flow of charges is not a flow of energy. But then what is an electric current? Under the definition of "electricity" used by all the non-scientists, an electric current IS NOT a flow of electricity!
Huh? Confused? You SHOULD be confused. There's something wrong here.
Note: my above statements about electricity and energy would be accepted by most scientists throughout history, including Ben Franklin, Michael Faraday, James C. Maxwell and Robert Millikan. I'm using the word electricity in the same manner as they did: electricity is the positive and negative "stuff" that's found in all electrons and protons. It is the "substance" that flows along inside of the wires. When it flows, these scientists would call it a "current of electricity." They'd say that any charged object has a "charge of electricity," and that electrons and protons are "particles of electricity."
Without realizing it, the electric companies and the K-6 science textbooks are trying to re-define the original meaning of the word electricity. How can such a thing happen? I'll examine this, but first here are more facts about "electricity" as scientists use the word.
MORE TRUE STATEMENTS ABOUT "ELECTRICITY"
- In a DC circuit, the electricity within the wires flows exceedingly slowly; at speeds around inches per minute. At the same time, the electrical energy flows at nearly the speed of light.
- If we know the precise amount of electricity flowing per second through a wire (the Amperes,) this tells us nothing about the amount of energy being delivered per second into a light bulb (the Watts.) Amperes are not Watts, an electric current is not a flow of energy; they are two different things.
- In an electric circuit, the flow of the electricity is measured in Coulombs per second (Amperes.) The flow of energy is measured in Joules per second (Watts.) A Coulomb is not a Joule, and there is no way to convert from Coulombs of charge into Joules of energy, or from Amperes to Watts. A quantity of electricity is not a quantity of energy.
- Electrical energy is electromagnetism; it is composed of an electromagnetic field. On the other hand, the particles of electricity (electrons) flowing within a wire have little resemblance to an electromagnetic field. They are matter. Electricity is not energy, instead it is a major component of everyday matter.
- In an electric circuit containing coils, if we reverse the polarity of voltage while the direction of the flowing electricity remains the same, then the direction of the flowing energy will be reversed. Current same; energy flow reversed? Yes. A flow of energy does not follow the direction of the flowing electricity. You can know everything about the direction of the electricity within a wire, but this tells you nothing about the direction of the flowing electrical energy.
- In any electric circuit, the smallest particle of electrical energy is NOT the electron. The smallest particle of energy is the "unit quantum" of electromagnetic energy: it is the photon. Electrons are not particles of EM energy, neither do they carry the energy as they travel in the circuit. Electricity is 'made' of electrons and protons, while electrical energy is electromagnetism and is 'made' of photons.
- In the electric power grid, a certain amount of energy is lost because it flys off into space. This is well understood: electrical energy is electromagnetic waves travelling in the air, and unless the power lines are twisted or somehow shielded, they will act as 60Hz antennas. Waves of 60Hz electrical energy can spread outwards into space rather than following the wires. The power lines can even receive extra 60Hz energy from space, from magnetic storms in Earth's magnetosphere. Electric energy is gained and lost to empty space while the charges of electricity just sit inside the wires and wiggle. Energy is not electricity.
- In an electric circuit, electrical energy does not flow inside the copper. Instead it flows in the empty air surrounding the wires. This fact is hidden because we calculate energy flow by multiplying voltage times current. College-level physics books describe a less misleading method of measuring this energy flow: take the vector cross-product of the E and M components of the electromagnetic field at all points in a plane penetrated by the wires. We call this the Poynting Vector field. Add these measurements together, and this tells us the total energy flow (the Joules of energy that flow each second through the plane.) In other words, in order to discover the rate of energy flow, don't look at the flowing electrons. The electricity flow tells us little. Instead look at the electromagnetic fields which surround the wires.
How can dictionaries, encyclopedias, and textbooks make such a gigantic error about electricity? I'm not certain, but I suspect that the mistake was missed because it slowly crept into the books over many decades. Most people practice "learning" rather than "unlearning." Since we accumulate knowledge rather than busting misconceptions, we never stumbled across the problem. Since most people don't really understand electrical physics, nobody complained, or even noticed. And if you raise the temperature of the lobster pot slowly enough, the live lobsters won't realize that they're in trouble! (grin)
What about the experts? Why don't the science experts complain? Here's one reason: modern scientists used the term "electricity" less and less over the years. Perhaps they're aware of the creeping distortion of the word "electricity", and so they avoid using it. Instead they adopted some improved terminology. Scientists of today don't say "charges of electricity" anymore. Instead they call it "electric charge." Also, modern scientists no longer say that electric current is "a flow of electricity." Instead they call it "a flow of charge." They also say that electrons are "charge carriers" rather than "particles of electricity." Even Faraday's Law has been changed, and today scientists usually speak of "quantities of charge" rather than the "quantities of electricity" discussed in the traditional definition of the Electrolysis Law.
If today's scientists notice their textbooks asserting that "electricity is energy", they will not necessarily realize that this is an error. They will not realize that the phrase "electricity is energy" makes the same mistake as this erroneous statment: "electric charge is a type of energy." Scientists no longer use word "electricity" in their day-to-day science profession, they mostly use it when explaining physics to children. As a result, they don't rigorously police their own usage of the word "electricity" in uncritical situations, and they don't notice when children's textbooks get it wrong.
Also, contemporary scientists are in the same position as everyone else: they learned some of their terminology in elementary school, and if their books were wrong, their minds might still retain those errors. If every one of us learns in grade school that the charges of "electricity" are a form of energy, we may remain blind to the contradictions even when we grow up to become scientists. The scientists put the mistakes in a mental pigeonhole and never use them during work, but they still may bring them out when explaining electricity to non-experts. I caught myself doing this at the start. I doubt I'm the only one with this problem.
Another reason why the error was never fixed: if an error becomes extremely widespread, and hundreds of thousands of people begin making the same mistake, then the error will become invisible. Those people will refuse to even acknowledge the error as being an error. After all, this many people cannot be wrong! Oh yeah? The majority rules? Not where the real world is concerned! It doesn't matter how many people make a factual error: the error remains just as wrong. However, any expert who objects, and who tries to fix the massive error, they will perhaps be seen as grammar-nitpickers living in ivory towers. The ones who have the ambition to point out the error are easily ignored because they are so few.
In most school subjects, majority does rule, and the "grammar nitpickers" are actually wrong. For example, if millions of people use slang words in their daily speech, then eventually those slang words will become acceptable. The words themselves didn't change ...yet they're no longer slang. As the slang is used over many years, dictionaries eventually include those words (dictionaries RECORD definitions, they don't promote them, and the common mistakes are recorded too.) Eventually all the dictionaries will include the slang words, and those words will become proper English and will be slang no longer. For this reason, people usually ignore Grammarians who object to the "misuse" or "corruption" of the English language. Such misuse is a matter of opinion.
But Science classes are different than English classes. In Science, reality rules, and if a large group of non-scientists tries to change the description of the real world, then that large group falls into error. It doesn't matter how many people "vote" for the change, because Nature isn't listening. If "electricity" originally means electric charge, and if people try to change things so that the word "electricity" now means energy, then we have a special word for their actions: MISTAKEN TERMINOLOGY.
I don't quite know how to solve the problem regarding the word "electricity." Too many reference books contain the errors. The word has been misused for so many decades that I am tempted to follow the lead of the scientists: just give up! Just admit that the word Electricity is irretrievably contaminated, and simply abandon it. Abandon it silently, that way nobody has to get embarrased. Yet doing this silently has caused serious problems in the past. It doesn't fix the problem, it just covers it up.
Abandoning the word electricity might defend Science against the brain-damage caused by contradictory terminology, but it does nothing to fix all of the reference books which are filled with confusing explanations of "electricity." More importantly, if we quietly abandon the word "electricity" without discussion, this will do nothing to help all of the poor souls who are currently confused by the incorrect "electricity" concepts. Neither will it give any aid to all of the poor science students who are butting their heads against the contradictory material still present in their science textbooks.
William Beaty 1999 souce : http://amasci.com
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