It boils down to the sloppy use of "definitions" in physics, the so called hard science with strict definitions.
I am watching the MIT EM Lecture series.
Dispite a education and 10 years experience in electronics through the 80's, I find the inexact use of definitions to still be a minefield dispite having learned the Aether Physics Model which was the first theory to explain mass to me in simple english without chasing its tail. The study of "electricity" is fraut with contradictory definitions.
Case in point the word Electricity itself.
I like the elastic tension way to describe how strings would impart relationship instead of a field anology. It could also be stated that potential energy (tension) is net electrostatic charge on the voltage hill and kinetic energy (motion) is current, as explained below.What Is "Electricity"?
(c)1996 William J. Beaty
Electrical Engineer
SEE ALSO:
Scientist's definition of Electricity
Electricity is not Energy
What is electricity, REALLY?!
What is electricity? This question is impossible to answer because the word "Electricity" has several contradictory meanings. These different meanings are incompatible, and the contradictions confuse everyone. If you don't understand electricity, you're not alone. Even teachers, engineers, and scientists have a hard time grasping the concept.
Obviously "electricity" cannot be several different things at the same time. Unfortunately we have defined the word Electricity in a crazy way. Because the word "electricity" lacks a distinct meaning, we can never pin down the nature of electricity. In the end we are forced to declare that there's no such stuff as "electricity" at all! Here's a quick example to illustrate the problem.
Do generators make electricity? To answer this question, consider the household light bulb. In a lamp cord the charges (electrons) sit in one place and wiggle back and forth. That's AC or alternating current. At the same time, the waves of electromagnetic field move rapidly forward. The wave energy does not wiggle, instead it races along the wires as it flows from the distant generators and into the light bulb. OK, now ask yourself this: is an electric current a flow of "electricity?" If so, then we MUST say that the "electricity" sits inside the wires and vibrates back and forth. It does not flow forward. Next, ask yourself if electricity is a form of energy. If it's energy, then "the electricity" DOESN'T wiggle back and forth within the wires, instead it's made of EM fields and it races forward at high speed. But it cannot do both! Which one is "the electricity", the wiggling electrons, or the high-speed EM field energy? The reference books give conflicting answers, so there *is* no answer.
If someone asks whether generators make electricity, it exposes a great flaw in the way we talk about "electricity". If we can repair this flaw, perhaps our explanations will finally make sense.
Below are the most common meanings of the word Electricity. Which one do you think is right? Think about it carefully. If one of these meanings is correct, all the others must be wrong! After all, no "science term" must ever have several conflicting definitions. Unfortunately dictionaries and encyclopedias have all of these contradictions. (Click the links to find out more about each one.)
1. The scientist's definition: "Electricity" means only one thing: it's the electrons and protons, the electric charge.
Examples: CURRENT OF ELECTRICITY. QUANTITY OF ELECTRICITY. COULOMBS OF ELECTRICITY.
2. The everyday definition: "Electricity" means only one thing: the electromagnetic field energy sent out by batteries and generators.
Examples: PRICE OF ELECTRICITY. KILOWATT-HOURS OF ELECTRICITY.
3. The grade-school definition: "Electricity" means only one thing: it refers to the flowing motion of electric charge.
Examples: "CURRENT" ELECTRICITY. AMPERES OF ELECTRICITY.
4. "Electricity" means only one thing: it refers to the amount of imbalance between quantities of electrons and protons.
Example: "STATIC" ELECTRICITY. DISCHARGE OF ELECTRICITY.
5. "Electricity" is nothing other than the classes of phenomena involving electric charges.
Examples: BIOELECTRICITY, PIEZOELECTRICITY, TRIBOELECTRICITY, THERMOELECTRICITY, ATMOSPHERIC ELECTRICITY ...ETC.
6. Other less common definitions:
"Electricity" refers to the flowing motion of electrical energy (electric power, Watts of electricity)
"Electricity" really means the electric potential or e-field (Volts of electricity)
"Electricity" only means the glowing nitrogen/oxygen plasma (sparks of electricity)
"Electricity" is nothing but a field of science (Basic Electricity, Advanced Electricity)
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ELECTRICITY, n.
The power that causes all natural phenomena not known to be caused by something else.
(Ambrose Bierce, The Devil's Dictionary, 1911)
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If we wish to agree on a single correct definition of "electricity," which definition should we choose? Well, maybe we don't need to choose just one. Suppose we ignore all these contradictions and instead pretend that ALL of the above definitions are true. Below is the "clear" and "simple" description of electricity that results:
Electricity is a mysterious incomprehensible entity which is invisible AND visible BOTH AT THE SAME TIME. Also, it's both matter and energy. It's a type of low-frequency radio wave which is made of protons. It is a mysterious force which looks like blue-white fire, and yet cannot be seen. It moves forward at the speed of light... yet it vibrates in the AC cord without flowing forwards at all. It's totally weightless, yet it has a small weight. When electricity flows through a light bulb's filament, it gets changed entirely into light. Yet no electricity is ever used up by the light bulb, and every bit of it flows out of the filament and back down the other wire. College textbooks are full of electricity, yet they have no electric charge! Electricity is a class of phenomena which can be stored in batteries! If you want to measure a quantity of electricity, what units should you use? Why Volts of electricity, of course. And also Coulombs of electricity, Amperes, Watts, and Joules, all at the same time. Yet "electricity" is a class of phenomena; it's a type of event. Since we can't have an AMOUNT of an event, we can't really measure the quantity of electricity at all... right?
Heh heh.
Does my description above sound stupid and impossible? You're right. It is. The word "electricity" has contradictory meanings, and I'm trying to show what happens when we accept more than one meaning. Electricity is not both slow and fast at the same time. It is not both visible and invisible.
Instead, approximately ten separate things have the name "electricity." There is no single stuff called "electricity." ELECTRICITY DOES NOT EXIST. Franklin, Edison, Thompson, and millions of science teachers should've had a long talk with Mrs. McCave before they decided to give a variety of independent science concepts just one single name.
Mrs. McCave was invented by Dr. Seuss. She had twenty three sons. She named them all "Dave."
Whenever we ask "WHAT IS ELECTRICITY," that's just like asking Mrs. McCave "WHO IS DAVE?" How can she describe her son? There can be no answer since the question itself is wrong. It's wrong to ask "who is Dave?" because we are assuming that there is only one Dave, when actually there are many different people. They all just happen to be named Dave. Who is Dave? Mrs. McCave cannot answer us until she first corrects our misunderstanding.
For the same reason, we will never find a simple answer to the question "what is electricity?" because the question itself is wrong. First we must realize that "electricity" does not exist. There is no single thing named "electricity." We must learn that, while several different things exist in wires, people wrongly all of them by a single name.
So never ask "WHAT IS ELECTRICITY". Instead, discard the word "electricity" and instead use the correct names for all the separate phenomena. Here are a few of them:
What is electric charge?
What is electrical energy?
What are electrons?
What is electric current?
What is an imbalance of charge?
What is an electric field?
What is voltage?
What is electric power?
What is a spark?
What is electromagnetism?
What is electrical science?
What is electrodynamics?
What is electrostatics?
What are electrical phenomena?
The above questions all have sensible answers. But if you ask WHAT IS ELECTRICITY?, then all of the answers you'll find will just confuse you, and you'll never stop asking that question.
ISN'T THIS JUST NITPICKING?!
SCIENTISTS' DEFINTION OF ELECTRICITY
ELECTRICITY IS NOT ENERGY
HOW SHOULD WE TEACH ELECTRICITY?
WHAT IS ELECTRICITY, REALLY?
MORE ABOUT "ELECTRICITY" 30 misconceptions that screwed *me* up.
ELECTRICITY DOES NOT EXIST
ELECTRICITY IS NOT ENERGY
ELECTRICITY Q & A
MORE ELECTRICAL ARTICLES HERE
GOOGLE SEARCH: Define 'Electricity'
GOOGLE SEARCH: "What is electricity?"
(Note the many contradictory definitions found on other sites.
They all give answers, but they don't agree among themselves!)
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This is part of Bill B's SCIENCE HOBBYIST website.
http://amasci.com/miscon/whatis.html
Voltage Energy
Voltage is intimately connected with electrical energy. So is magnetism. We can even say that electrical energy is the fundamental object of our study, while voltage and magnetism are the two faces it displays to the outside world. Another analogy: in mechanical physics, both the Kinetic energy (KE) and the Potential energy (PE) are part of matter: relative motion of an object has Kinetic Energy, and stretched or compressed objects (e.g. springs or rubber bands) have Potential Energy. In a similar way, electrical kinetic energy appears whenever positive charges flow through negative charges. We call this "electric current," and it causes magnetism. On the other hand, electrical potential energy appears whenever positive charges are yanked away to a distance from their corresponding negative charges. We call this "net electrostatic charge," and it causes voltage. Electrical KE is associated with current, and electrical PE is associated with voltage. If electrical energy is the same as Electromagnetism, then maybe we should be more sensible and name it "VoltageCurrent-ism."
Potential Energy vs. "Potential"
Voltage is also called "electrical potential."
So... is voltage a type of potential energy? Close, but not totally accurate. Confusion between voltage and potential energy is a common mistake. Think of it like this. If you roll a big boulder to the top of a hill, you have stored some potential energy. But after the boulder has rolled back down, THE HILL IS STILL THERE. The hill is like voltage: the height of the hill has "Gravitational Potential." But the hill is not *made* of Potential Energy, since we need both the hill *and* the boulder before we can create potential energy. The situation with voltage is similar. Before we can store any ELECTRICAL potential energy, we need some charges, but we also need some voltage-field through which to push our charges. The charges are like the boulder, while the voltage is like the hill (volts are like height in feet. Well, sort of...) But we wouldn't say that the Potential Energy is the boulder, or we wouldn't say the hill is the PE. In the same way, we should not say that electric charges are Potential Energy, neither should we say that voltage is Potential Energy. However, there is a close connection between them. Voltage is "electric potential" in approximately the same way that the height of a hill is connected with "gravitational potential." You can push an electron up a voltage-hill, and if you let it go it will race back down again.
Currents don't have Voltage
Voltage is not a characteristic of electric current. It's a common mistake to believe that a current "has a voltage" (and this mistake is probably associated with the 'current electricity' misconception, where people believe that 'current' is a kind of substance that flows). Voltage and current are two independent things. It is easy to create a current which lacks a voltage: just short out an electromagnet coil. It is also easy to create a voltage without a current: flashlight batteries maintain their voltage even when they are sitting on the shelf in the store. Water analogy: Think of water pressure without a flow. That's like voltage alone. Now think of water that's coasting along; a water flow without a pressure. That's like electric current alone.
http://amasci.com/miscon/voltage.html