A “CONDUCTOR” IS A MATERIAL WHICH ALLOWS CHARGE TO PASS THROUGH IT? (William J. Beaty)


Not exactly. The scientist’s definition of the word “conductor” is different than the one above, and the one above has problems. For example, a vacuum offers no barrier to flows of electric charges, yet vacuum is an insulator. Vacuum is NOTHING, so how can it act as a barrier to electric current? Also, there is a similar problem with air: electric charges in the air can easily move along, yet air is an insulator. Or look at salt water versus oil. Oil is an insulator, while salt water is a conductor, yet neither liquid is able to halt the flow of any charges which are placed into it. How can we straighten out this paradox? Easy: use the proper definition of “conductor.” BAD:
Conductor – a material which allows charges to pass through itself BETTER:
Conductor – a material which contains movable electric charges If we place a Potential Difference across either air or a vacuum, no electric current appears. This is sensible, since there are few movable charges in air or vacuum, so there can be no electric current. If we place a voltage across a piece of metal or across a puddle of salt water, an electric current will appear, since these substances are always full of movable charges, and therefor the “voltage pressure” causes the charges to flow. In metal, the outer electrons of the atoms are not bound upon individual atoms but instead can move through the material, and a voltage can drive these “liquid” electrons along. In salt water, the individual sodium ions and chloride ions are free to flow, and a voltage can push them so they flow as an electric current. If we stick our wires into oil, there will be no electric current, since oil does not contain movable charges. If we were to inject charges into a vacuum, then we WOULD have electric current in a vacuum. This is how CRT’s and vacuum tubes work; electrons are forcibly injected into the empty space by a hot filament. However, think about it for a second: it’s no longer a vacuum when it contains a cloud of electrons! 🙂 Maybe we should change their name to “electron-cloud tubes” rather than “vacuum tubes”, since the electron cloud is required before there can be any conductivity in the space between the plates. (But vacuum tubes already have another name, so this would just confuse things. They are called “hollow-state devices.” As opposed to “solid state devices?”

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ELECTRIC CHARGES ARE INVISIBLE? (William J. Beaty)


No. Electric charges are very visible, even though their motion is not.

ELECTRIC CHARGES ONLY FLOW ON THE SURFACES OF WIRES


Wrong. The flow of electricity along a wire is a form of dissipation of electrical pressure and therefore generally tends to be a surface phenomenon, flowing over the greatest surface area, which offers the least amount of resistance, and which forms the pressure boundary. Though thin, hollow metal pipes usually make poor conductors as their capacity to carry a current is low.  In solid conductors the electrical pressure will flow through the entire conductor if there is sufficient resistance in the form of limited capacity on the surface. It is this reason it is better to use solid wires which offer greater current carrying capacity and are less prone to overheating.

Rather than “conducting” it would be better to think of the conductor as a channel where electrical pressure can be dissipated in the same way a flood would spread across a landscape flowing along the path of least resistance.

Personally I disagree with the electron theory as I have outlined in “Electrostatic Theory is Wrong”, but William Beaty explains the present electron theory in relation to this subject well…

“Unfortunately, the word “charge” refers to two different things. When electric charge is placed on a metal object, the added charge is just a drop in the bucket compared to the amount of charge already in the neutral metal. “Uncharged” wires contain an enormous amount of charge, even though they may have “zero charge” on their surfaces. Confused yet? All metals contain huge amounts of movable electrons. During an electric current it is these electrons which flow. However, each electron is near a proton, and so the metal is said to be “uncharged.” In a wire, electric current is a flow of “uncharged charge”. Weird but true. Now if we were to place EXTRA charge upon a wire, that would be like pouring a teacup into the ocean. The “water level” would rise a tiny bit. Yet extra charges on a wire create a very noticeable electrical imbalance (they attract lint, deflect electroscopes, make sparks, etc.) It isn’t so strange that we might accidentally assume that the extra charges are the only charges there. Yet in reality, electric currents happen in the “ocean” of the wire, and the extra “teacup” has little effect on the charge flow. The charge flow (current) is not just on the surface. A second source of misunderstandings: during high frequency AC, the electric current on the surface of a conductor is higher at the surface than it is within the bulk of the metal. This is called the “skin effect.” It is not important for everyday wires at 60Hz. Perhaps some people heard about the Skin Effect but did not realize that it only works for high frequency AC. At extremely high frequencies, the current does flow as a “skin” on the surface of large wires. For high-current, high-frequency circuits such as radio transmitters, it makes sense to use copper pipes as conductors. All the charge flow is on the surface of the conductors. All the heating takes place on the surface, and not deep within the metal.”


ELECTROMAGNET COILS USE UP ENERGY TO MAKE MAGNETISM? (William J. Beaty)


Not right. Sustaining a magnetic field requires no energy. Coils only require energy to initially create a magnetic field. They also require energy to defeat electrical friction (resistance), to keep the charges from slowing down as they flow in wires. But if the resistance is removed, the magnetic field can exist continuously without any energy input. If electrically frictionless superconductive wire is used, a coil can be momentarily connected to an energy supply to create the field. Afterwards the power supply can be removed and both the current and the magnetic field will continue forever without further energy input.

LIGHT AND RADIO WAVES TRAVEL AT 186,000 MILES PER SECOND? (William J. Beaty)


No. They only travel at 186,000 miles per second while in a perfect vacuum. Light waves travel a bit slower in the air, and it travels LOTS slower when inside glass. Radio waves move much slower than 186,000 miles/sec when they travel within plastic-insulated coaxial cable. The term “speed of light” is misleading, because the complete term actually reads “speed of light in a vacuum.” There actually is no set “speed of light,” for light waves and light (and electrical energy) can travel at many different speeds depending on the medium through which the waves propagate.

ELECTRIC POWER FLOWS FROM GENERATOR TO CONSUMER? (William J. Beaty)


Wrong. Electric power cannot be made to flow. Power is defined as “flow of energy.” Saying that power “flows” is silly. It’s as silly as saying that the stuff in a moving river is named “current” rather than named “water.” Water is real, water can flow, flows of water are called currents, but we should never make the mistake of believing that water’s motion is a type of substance. Talking of “current” which “flows” confuses everyone. The issue with energy is similar. Electrical energy is real, it is sort of like a stuff, and it can flow along. When electric energy flows, the flow is called “electric power.” But electric power has no existence of its own. Electric power is the flow rate of another thing; electric power is an energy current. Energy flows, but power never does, just as water flows but “water current” never does. The above issue affects the concepts behind the units of electrical measurement. Energy can be measured in Joules or Ergs. The rate of flow of energy is called Joules per second. For convenience, we give the name “power” to this Joule/sec rate of flow, and we measure it in terms of Watts. This makes for convenient calculations. Yet Watts have no physical, substance-like existence. The Joule is the fundamental unit, and the Watt is a unit of convenience which means “joule per second.” I believe that it is a good idea to teach only the term “Joule” in early grades, to entirely avoid the “watt” concept. Call power by the proper name “joules per second”. Only introduce “watts” years later, when the students feel a need for a convenient way to state the “joules per second” concept. Unfortunately many textbooks do the reverse, they keep the seemingly-complex “Joule” away from the kids, while spreading the “watt” concept far and wide! Later they try to explain that joules are simply watt-seconds! (That’s watts TIMES seconds, not watts per second.) If you aren’t quite sure that you understand watt-seconds, stop thinking backwards and think like this: Joules are real, a flow of Joules is measured in Joules per second, and “Watts” should not interfere with these basic ideas.

“STATIC ELECTRICITY” IS ELECTRICITY WHICH IS STATIC? (William J. Beaty)


Wrong. “Static electricity” exists whenever there are unequal amounts of positive and negative charged particles present. It doesn’t matter whether the region of imbalance is flowing or whether it is still. Only the imbalance is important, not the “staticness.” To say otherwise can cause several sorts of confusion. All solid objects contain vast quantities of positive and negative particles whether the objects are electrified or not. When these quantities are not exactly equal and there is a tiny bit more positive than negative (or vice versa), we say that the object is “electrified” or “charged,” and that “static electricity” exists. When the quantities are equal, we say the object is “neutral” or “uncharged.” “Charged” and “uncharged” depends on the sum of opposite quantities. Since “static electricity” is actually an imbalance in the quantities of positive and negative, it is wrong to believe that the phenomena has anything to do with lack of motion, with being “static.” In fact, “static electricity” can easily be made to *move* along conductive surfaces. When this happens, it continues to display all it’s expected characteristics as it flows, so it does not stop being “static electricity” while it moves along very non-statically! In a high voltage electric circuit, the wires can attract lint, raise hair, etc., even though there is a large current in the wires and all the charges are flowing (and none of the electricity is “static.”) And last, when any electric circuit is broken and the charges stop flowing, they do *not* turn into “static electricity” and begin attracting lint, etc. A disconnected wire contains charges which are not moving (they are static,) yet it contains no “static electricity!” To sort out this craziness, simply remember that “static electricity” is not a quantity of unmoving charged particles, and “static electricity” has nothing to do with unmoving-ness. If you believe that “static” and “current” are opposite types of “electricity,” you will forever be hopelessly confused about electricity in general.

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