User talk:Ghitis

SECOND (and LAST) DIALOGUING On FORCE


 * Jacob, it seems that the word "force" is commonly used in two ways. Classically, it is defined as the rate of change of momentum with respect to time. The other is the “Field of Force.”

I posit that force is the use of Energy (kinesis or “energus,” as I call it) to perform an action. This is the opportunity to say that I do not like the definition of Energy as “…that which can do work, and work is moving an object from A to B…” I say that Energy is what can perform an action. Thus, force is the application of energy to perform an action. An action follows the Principle Of Least Action, which is the maximal possible economical way that energy acts. When excessive force is applied for a given action, the superfluous energy is dissipated. I posit that force is the “interface” in the transfer or in the transduction of energy from donor to receptor. The transfer or transduction is absolute in chemical processes, but not so in biochemical processes. In these latter reactions, energy may be dissipated. Biochemical processes have developed enzymes to hasten the molecular changes; therefore, I posit that the enzymes are the “interface” equivalent to force in the world of the living. Evolution, therefore, has decreed how “fast” life “acts,” and it appears to be a million times slower compared to the actions of fast physicochemical actions. ACTION should be considered at the relativity level, because since velocity and gravity affect time, then they affect action. But maybe it is the other way around, and the “change in time” is actually “change in action.” This means that the different rate of “physical” and of “live” (biophysical) actions must be taken in consideration when figuring the respective rate of “aging” of a clock versus an austronaut on a space craft. Thus, at a hight of 20,000 km. a watch acts daily at about 50 microsec. faster than on earth; this is significant in specific cases, yet since the fastest biochemical processes are at a possible minimum some 1,000,000 times slower, the austronaut would age about a million times slower than the watch, still a really negligible figure. This is not idle talk, in the light of the importance of the relativity effects on the atomic clocks of Global Positioning Systems (GPS). I am writing this to stress that the manifestation of energy is action, not “work”.
 * Heron, that ”classical definition” of force is practically incomprehensible. I prefer the definition that force is what changes the acceleration or the shape of an object. But still, such definition is just descriptive; it does not truly gives one a sense of depth of understanding.
 * This might be a place to consider the 3d. Law of Motion, which deals with “reaction.” An example for that phenomenon is having yourself (the donor)  pushing a body (the receptor) while floating in a space vehicle. When you do that, you are actually also pushing yourself as an effect of the receptor body’s inertia, so that there you have the simultaneous reaction.   (You may just ride on a children’s swing and push the sitting neighbor.) Well, this "reaction" is actually a reciprocal action, in which mass (inertia) determines the reciprocal effects.  If yours  and the receptor’s mass are identical, half of the energy applied by the force (pushing) is equally divided.
 * More recently, force has been defined as one of the four interactions - electromagnetism, gravity, weak and strong nuclear interactions. Note that Wikipedia's article on these "forces" is entitled "Fundamental interaction" and not "Fundamental force". This choice of title wisely avoids the confusion between the two uses of the word "force".

As for the Fields of Force: They are the electric and the magnetic; the gravitational field is being is still being debated. These fields have no force in themselves and only act as intermediates, “interfaces,” to allow kinesis (which I deem as being ENERGY, so that I will call it "energus" for the purpose of our dialogue). Kinesis is associated with given electrons, and is transduced (transferred and also changed into a different class of kinesis --i.e., energy, energus) -- to other electrons. When these latter electrons are the specific ones in a conducting metal, the kinesis -energus- is now electric energy (which I call "kinetric"). This effect is obtained when the kinetic energy (not so felicitously named “mechanical”) from a turbine causes the specific, mobile, electrons of a wire coil to disturb the magnetic field of force of the generator: the kinesis is now transduced to them, and they now run with nearly the same kinesis, but now this kinesis will cause an action at specific sites of their route along a wire. Kinetric can act, as all energy does, only when there is partial opposition (resistance) to its undisturbed flow. These disturbers are called “load.”
 * You refer to nuclear forces, which should not create confusion, but still, it is a welcome choice.
 * Yes, Jacob, I understand the distinction between a force and a field of force. The latter is something that, as far as I know, can only be defined by listing its properties, such as its ability to cause the former (mechanical force). Nobody knows what these fields are "made of". I also agree that an electric current, at least in a metal, is a combination of electric charge (held in a material you call electrus) and kinetic energy.

--- Ghitis 15:57, Sep 5, 2004 (UTC)
 * Less known is that an electric field moving in a differnet electric field spawns a magnetic field. This phenomenon is being exploited to make Magnetic RAM, memory that remains after the electric current ceases. But what I wished to stress is the role of fields of force in the transduction of energus (kinesis). Going on into Philosophy of Physics, there appears that motion, the essence of energy, truly is a “disturbance” of the fields of force. I wonder if what is written in Genesis about “…spirit of God moving upon the waters…” should not be interpreted as rather indicating that the spirit’s movement was the actual creator.

First Dialogue on  ELECTRIC WIRING FROM POWER STATION TO CONSUMER 

Jacob, the transmission line [from the substation] is a pair of wires, live and neutral. The substation, transmission line and load (the appliances of the consumer) together form a circuit.


 * Heron, to speak of a circuit I need to know how the power lines leave the substation and how they return to it. I think in terms of a simple generator (a dynamo). When a house is constructed, how is the procedure to provide it with electrical current: What steps, one by one, are taken, by whom and what for, in detail, from the transformer on the street, to the house, and back to the transformer. This is asking a lot, but it is essential; no more questions for now. -- Ghitis 09:22, Aug 18, 2004 (UTC)

Second Dialogue on ELECTRIC WIRING 

Jacob,...the diagram I drew for you on the Reference Desk page… was a circuit...
 * NOTE for the onlooker: This is a slow ongoing process with deletions and corrections until the whole task is complete.


 * Heron, may I say that all the circuits should be defined: Primary, at the generator level: where is out (only the two wires that carry to the up-transformer, with no phases yet), and where is return to the generator.Ghitis 16:14, Aug 20, 2004 (UTC)

OK, let's stick with the case of a single phase (although I don't know if single-phase transmission lines are actually used). We can widen it to three phases later. The first circuit consists of the winding of a generator linked by two wires to the primary winding of a step-up transformer (tens or hundreds of metres away). The second circuit consists of the secondary winding of a step-up transformer linked by two very long wires (the long-distance transmission line, perhaps hundreds of kilometres long) to the primary winding of a step-down substation transformer. The third circuit consists of the secondary winding of the substation transformer connected by two medium-length wires (perhaps a few tens or hundreds of metres) to the customer's premises, where numerous loads may be connected in parallel. There may also be several customers on the same local line, all connected in parallel with each other. Like this:

(-)||(-)||(-++---...  ||||(         |    |  G( (1) )||( long-distance transmission line )||(   (3)  [L1] [L2]   ||(              (2)                )||(         |    | (-)||(-)||(--+--++---...        SUT                                  SDT   |                                                    |                                                    V                                                  Earth
 * Key: G = generator winding
 * SUT = step-up transformer (near generator)
 * SDT = step-down transformer (near customers)
 * L1,L2 = customers' loads
 * 1,2,3 = first (low-voltage), second (high-voltage), third (low-voltage) circuits

Each of the three circuits has a source, a load and two wires between them. There is no distinction between "out" and "return", since the current is alternating. :--Heron 20:17, 20 Aug 2004 (UTC) ...I hope we can agree on that basic point. There is a continuous loop of wire from the top of the generator, along the live wire to the consumer's premises, through all the consumer's appliances to the neutral wire, and back along the neutral wire to the bottom of the generator. The current then goes through more wires inside the generator, back to where we started, and begins its next journey around the circuit. Let me know if you are happy with this description, and then I will move on to the next point. I think we need to take this slowly to avoid any misunderstandings. Electronic communication has its limitations, and teaching by Wiki is a slow process. -- Heron 08:24, 20


 * Heron, not so clear: 1. Since the current is carried by both wires half of the time, the load gets the energus from both wires, and the consumer pays as he does for water, just what is consumed. But it appears that a lot of energus is lost by the wire connected to earth for "safety reasons."! Where does this wiring occur? 2. What are all the other connections that "ground" the wiring? -- Ghitis 17:37, Sep 7, 2004 (UTC)

-- 1. Jacob, it is not true to say that the current is carried by both wires half the time. In fact it is carried by both wires all the time. The current I in the circuit is a sinusoidal function of time t -
 * $$I(t) = I_p\sin\left( 2\pi ft\right)$$

(where Ip is the amplitude of the current and f is its frequency), and is the same at every point around the circuit (except perhaps in the generator winding where things might be more complicated, but we can ignore this). As you can see from the equation, the current is sometimes positive, sometimes negative, and sometimes zero, but is always the same at every point in the circuit. This is because there are no delay elements (inductors or capacitors) in the circuit which could change the phase of the current.

Incidentally, we can also express the load voltage and power as follows. By Ohm's law, the voltage V across the load R is:
 * $$V(t) = I_p R \sin\left( 2\pi ft\right)$$.

The power P in the load is
 * $$P(t) = I(t)V(t)$$

which is another sinusoidal function, but with frequency 2f.

I have added the earth connection to my earlier diagram above. You will see that, since there is only one earth wire, there is no path for current to flow through the ground. Since there is no current through the ground, no power is lost there.

2. Ideally, there are no other earth connections. However, in reality, because the earth has a non-zero resistance, there are often multiple earth points for extra safety. This has the effect of sending some currents through the ground and, you are right, some power is wasted because of this, but only a tiny fraction of the power supplied to the load. --Heron 20:21, 7 Sep 2004 (UTC) Let's start with the meaning of "alternating current". Imagine a loop of copper wire. You move a magnet repeatedly backwards and forwards near the wire at one side of the loop, to simulate what happens inside the generator. As the magnet moves in one direction, it causes a pulse of current to flow in the loop - say clockwise. When the magnet stops moving for an instant, the current stops flowing for an instant. When the magnet then moves in the opposite direction, it causes the current to flow in the opposite direction - this time anticlockwise. This is what is meant by alternating current. If you draw a graph of current against time, it looks like this: current ^   |     *               *  + |   *   *           *   *    |  *     *         *     *         *    +-*---*---*---*-> time |         *     *         *     *  - |           *   *           *   *    |             *               * (Positive current corresponds to clockwise in our example, and negative current to anticlockwise.) It doesn't matter where you measure the current in the loop - you always get the same pattern. Now, imagine that you squash the loop into a very long, thin rectangle. You now have two parallel wires (call them AB and CD) joined by short links (AD and BC) at each end, as in the following diagram. A ++ B  |                                    | D ++ C This is an electrical circuit, resembling a power transmission line. If you now repeat the experiment, moving the magnet around near the short piece of wire called AD, the current will alternate as before. This time, however, when the current flows clockwise, it will flow from left to right in wire AB, and from right to left in CD. The reverse is true when the current flows anticlockwise. So, apart from the instant when the current stops as it changes direction, there is always a current flowing in both wires, because they are really just two sections of the same loop. (Note: in a mains power transmission system, the section BC would not be a simple piece of wire, as this would cause a short circuit and blow a fuse. But it serves to illustrate my explanation.) --Heron 20:05, 8 Sep 2004 (UTC)
 * Heron, this time I got the message sign
 * Positive and negative here are confusing, like positive and negative voltages.
 * Please describe a transmission line.
 * Then in a generator only the end of the coil is under the magnet? In the core, does the coil of copper, isolated by a cover of some material, return to the beginning of the core and go out together with the initiating tip as the two constituents of the transmission line?
 * Ok, the current is flowing, in alternating directions; this is of course true in the two components of the coil, but what about the transmission lines?
 * I disregard this paragraph in the meantime. -- Ghitis 07:22, Sep 9, 2004 (UTC) edit

The complete generator-transmission line-load circuit is like this:

+--+   |__        |                                +--+  _____)       |      Live                      |      | (_____        ++    +---+ _____)             Neutral                        | L | (_____        ++    +---+ _____)      |                                |      | (__G          |                                +--+ |         |    +--+

<- Power > <--- Transmission > <- Customer's -> Station or           Line or                   Premises Generator            Cable

L = load G = generator winding

The whole thing is a single circuit. If you wanted to, you could build the whole circuit out of one continuous loop of copper wire. In practice, there are lots of pieces of wire joined together by plugs and sockets, nuts and bolts, and solder. Notice that I have omitted the step-up and step-down transformers from this example. This is a simple, low-voltage mains supply arrangement that you might get from a portable, single-phase diesel-powered generator. In this case, what I have marked as "transmission line" would just be a length of flex from the generator to the load.

The generator winding is exposed to a rotating magnetic field, which causes the alternating current to flow. I have drawn the coil as a serpentine line, but I did not have space to draw the core, which is just a lump of iron around which the coil is wound. A real coil is a three-dimensional shape, but is topologically equivalent to what I have drawn here.

The transmission line is a pair of wires that could be slung from pylons, buried in the ground, or just wrapped in plastic and made into a cable. At this stage we can ignore the earth connection, which is a safety feature that is not present in all installations.

What I said before about the trivial ABCD circuit still applies to the new circuit that I have just drawn. --Heron 08:30, 9 Sep 2004 (UTC) Not all kinetrics is dissipated into heat: there is some transduction to the steps required to synthesize ozone. Now, is the copper coil wound around, or along the core of the generator? I am still waiting for the "earth" connections. -- Ghitis 00:40, Sep 10, 2004 (UTC)
 * Heron, I actually realized soon after writing the previous, that as you had stressed, kinetric is flowing in both directions simultaneously! thus, although alternating, it uses the wire to transport the kinesis that is transduced at the magnetic field, so that electrons are truly just carriers. Not so in DC in wire or in clouds of water or dust, where friction is the generator of the static field. The electrons move fast to the place where they are lacking, that is, go to positive ions. The resulting electric energy (kinetric) is the energus that the electrons had received from the transducer, the wind that caused the friction. That straight-forward kinetic energy was transduced into ionic potential energy, which is seen as an electric field betwen the + and - ions. But the field is a field of force, which will transduce into kinetric the potential energy of the electrons. The field decreases with each electron traversing it. The electrons will move very fast, because they are really "interested"! In lightning, the flow of electrons is along a bad conducting medium, so that there is intense heating, with resultant incandescence and blast along the electric field "chosen" by the electrons from several alternatives, if available, according to the principle of least action. Thus, I'm not convinced that there is a "discharge," an "arc of energy" jumping. Just the first heating of the air allowing for sufficient ionization to transport electrons, and the self-feeding process starts for lightning to proceed.
 * Heron, I'm thinking that there is no such a thing as a "circuit" except for the group of loads that share the same fuse, for convenience, especially when the refrigerator should not suffer because of a faulty bulb connection along the 'circuit.' You dislike the term 'current,' which is really a one-way path, like from a river to the sea, because the evaporation and subsequent clouds and rain are not part of a circuit.  Ghitis 11:13, Sep 12, 2004 (UTC)
 * There must be a continuous flow (current) in order to renew the electrons or electricons carrying the kinetric. This happens along the two wires connected to the load, say, the bulb. Yet I cannot envision how this energus comes from, if the two wires entering the premises just bring the current from the transformer. I am beginning to think that the wire to earth from the wire that will be called neutral, actually allows for current to flow, by using earth as the "sea" to which the current (electricons, electrons) flows, thus allowing for new one to arrive from the transformer. This means that the generator must have also a connection to earth. Generators that have no connection to earth, i.e., dynamos, have an interconnection between "out" and "in." The danger of not connecting one of the wires (the "neutral") derives, as I see it, from unwittingly becoming the "sea" to which the current flows. Thus, there IS a circuit in AC generation. Not so in DC, because the kinetrics flows for a short time, until all the electrons have moved to corresponding ions. -- Ghitis 07:51, Sep 13, 2004 (UTC)

No, Jacob, it doesn't work like that. Unless there is a fault, no current flows in the earth wire. The current flows round and round in the loop formed by the live and neutral wires (which are connected together at one end by the generator, and at the other end by the load, if there is one). With 50 hertz AC, the current flows round and round in one direction for ten milliseconds, then reverses and flows round and round in the opposite direction for another ten milliseconds, and so on. The electrons spend their whole lives trapped inside that circuit, just moving backwards and forwards. If you break the loop by disconnecting all the loads on that circuit, then no current flows anywhere. Forget about the earth: it does not contribute to the transfer of energy from producer to consumer, regardless of whether the circuit is open or closed. The electrons, or whatever you call the charge carriers, do work in the load by pushing against its resistance. Once they have done their work, they carry on round the circuit, but are never created or destroyed, replenished or depleted. --Heron 09:08, 13 Sep 2004 (UTC) Otherwise, I consider our dialogue on this subject as closed, to my satisfaction, thank you. -- Ghitis 19:02, Sep 13, 2004 (UTC)
 * OK, agreed: The only point to clarify is, how is the other line converted into a "neutral" or "cold" one by grounding it, and still be a conducting wire.

To answer your last point, let me refer back to the ABCD diagram I drew earlier. Replace the short segment AD with a 1-volt battery, and the short segment BC with a 1-ohm load. A current of 1 volt / 1 ohm = 1 ampere will flow. If the positive terminal of the battery is at the top, the conventional current will flow clockwise. The battery causes wire AB to be positive with respect to wire CD by a difference of one volt.

Notice that we have not specified the voltage of either wire with respect to ground. These voltages are unknown, and are irrelevant to the behaviour of the circuit ABCD. It is possible that wire CD is at ground potential, and then wire AB will be one volt above ground potential. It is equally possible that wire CD is one million volts above ground potential, which would make wire AB one million and one volts above ground potential. Whichever is the case, the current around the circuit and through the load will still be one ampere.

So far I have described only direct current. For alternating current, just image that you periodically reverse the battery connections. When the battery is the other way round, the current will be anticlockwise and the voltage across the load will have the opposite polarity.

Now, imagine that you connect wire CD to ground. This will cause the wire to be at ground potential, as in the first of the two possibilities I considered above. With the battery in its first position, wire AB will then be one volt above ground potential. With the battery reversed, wire AB will be one volt below ground potential. So, you now have alternating current with one wire earthed. The one ampere of current in the circuit continues to flow through the load, in alternating directions, and none of it flows to earth. CD is now the neutral wire, and AB the live wire. The current in CD is the same current that is in AB, because both wires are part of the same circuit, even though wire CD is earthed. --Heron 15:55, 18 Sep 2004 (UTC)
 * Sorry, but I cannot follow. In the mean time, could you explain the principle of the AC tester? How can it light up withouth the "circuit" being "closed"? I think I know the principle, and also the "secret" of the "neutral," but I do not dare expose it yet. Ghitis 10:13, Sep 19, 2004 (UTC)

By "AC tester", do you mean a screwdriver with a neon bulb in the handle? If so, that is a neon lamp, which does close the circuit, causing a small current (a milliampere or so) to flow. --Heron 17:21, 19 Sep 2004 (UTC)
 * Yes, but how is the "circuit" closed? Why should a current flow? From where? How is it closed? What is the principle? IT IS called Tester. -- Ghitis 12:27, Sep 20, 2004 (UTC)

Sorry. I wasn't clear about which circuit I was talking about. Here is a diagram.

B   A +-+---+ T      |                         |       | |                       +-+      |      ~                        |L|     -+- |                       +-+      N      |                         |      -+- D +-+ C    | |                               +-+      |                                |R| |                               +-+      |                                 |      |                                +-+      |                                |H| |                               +-+      |            Earth                | ...+.................................+...     V                                 U There are two circuits. The first is ABCD, consisting of a generator and a load. The second is ABTUVD.

T is the tip of the mains tester. N is the neon bulb inside the tester. (There is also a resistor R inside the tester, to reduce the amount of current that flows through you.) H is the human being, who acts as another resistor. U is the point at which the human being is earthed, usually his feet. The dotted line is the earth, which acts as another resistor allowing a small current to flow from U to V. V is the point at which the supply company's neutral wire is earthed (by the link DV). If the neon lamp glows, it means that point B is live.

Actually the load L does not need to be present for the tester to work. I just put that in so that you could relate this diagram to the earlier one. Also, the tester is not specific to AC. It would also work with DC.

I suspect that you are now going to ask me why the power company makes the link from D to V. This will take a long time to explain. Can I ask that you read Wikipedia's article about safety earthing - see Ground (electricity) - before asking me? Also, I fear that electricity companies in different parts of the world use different earthing systems, so what I can tell you about electrical safety in damp old Britain might not apply in dry countries. --Heron 12:58, 20 Sep 2004 (UTC)
 * Heron, thanks for your patience. But... I don't think you agree with the explanations, which seem to be standard, and which I just cannot accept. For instance, I don't accept that there is a "circuit" in a battery (the voltaic thing). I consider that the electrons from the negative run to the positive because there is an attraction. The electrons carry the kinetric equivalent to that which resulted in the separation of the two ionic moities. The kinetric causes heating of the wire and the battery if there is no load in the wire connecting the ions; this load determines the amount of kinetric flowing, which is expended on the electrons of the thing called load. By the same token, the person testing with a tester does not close a "circuit." In fact, his feet are not grounded! I think that the current just flows into the body of the person touching the tester; it is very weak, and it flows with no harm caused, and is converted into heat. I think there is a basic ignorance in this regard. Can you disabuse me? -- Ghitis 16:36, Sep 21, 2004 (UTC)

Because I am an engineer and not a physicist, I use the word "circuit" in a conventional sense. I do not mean a continuous metallic loop: I just mean any path through which a current can flow, or for practical purposes appears to flow. I realise that I am being philosophically lazy, and I can understand why you, a scientist, object to my terminology.

In the case of a battery, anions are chemically attracted to the anode, where they release electrons into the circuit. (That word circuit again. Here, I mean the network of wires and other components that is attached to the battery.)  The electrons travel through the circuit, doing work, eventually arriving back at the battery's cathode where cations are waiting to absorb them. It is the chemistry inside the battery that provides the energy to move the electrons. As you say, that energy, in the form of ions, was put inside the battery by the manufacturer. I agree with you that the inside of the battery is not a "circuit" in the strictest sense, because the electrons that go into the cathode are not the same ones as those that come out of the anode, but it is convenient to think of it as a circuit for the purposes of electrical calculations.

In the case of the mains tester, your feet are indeed grounded. Why do you say they aren't? You may be thinking that the rubber soles of your shoes are insulators, but this is not true: they are not perfectly insulating, and they allow a small current to flow through your body to ground - enough to light up the neon bulb. There really is a circuit here. Try standing on a thick sheet of glass: this is a very good insulator, and will stop the mains tester from working. Or try hovering above the ground in a helicopter - again, the mains tester held in your hand won't work. All the time, I am talking about damp European ground - I doubt that these testers work in sandy deserts. --Heron 20:43, 21 Sep 2004 (UTC)

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