Constant314

Hi, sorry I don't have an account and hope I'm formatting this correctly. Can we discuss your reversion of my edits on the Telegrapher's equations? I won't quibble over the edits on the Transatlantic Cable page, those were unimportant. But I don't understand why you didn't find the reference and text I added to the Telegrapher's Equation page, clarifying the Heaviside condition, as useful. I added it because I wanted to know what the condition was, and had to dig through primary sources to find it, so I thought I'd save others the trouble.

You said practically no cable is operated under those conditions. But in the past, loading coils or even high permeability magnetic tape or wire wrapped around the core were indeed used to more closely approach the Heaviside condition; see Practical use, and I can dig up more references on the web if you want.

And more to the point, why does the practical application (or not) of this condition in real cables dictate whether this information should be included in the article or not? Right now, if someone reads the Telegrapher's Equations page, there is no information available as to what conditions would allow a lossy line to transmit signals without distortion. Even if this arrangement of line constants hadn't ever been used in practice, wouldn't we want to at least note the condition just for academic interest? Can't we get something on the Telegrapher's Equation page which at least links to the Heaviside Condition from the appropriate place? Thanks, InductorMan

Have a look at this chart for a typical coaxial cable:

The Heaviside condition is G/ωC = R/ωL. That is where the blue curve intersects a red curve. For trans-Atlantic cable using gutta-percha, use the red curve labeled "Med" . To make the blue curve coinside with the red "Med" curve, you would have to increase inductance by 8 orders of magnitude. It isn't practical. If you did you would have a cable that met the Heaviside condition for frequencies below 0.01Hz. It would not be usable for telegraphy. It is true that they did use permalloy loading to increase the inductance, but they never got close to the Heaviside condition. Constant314 (talk) 17:49, 6 July 2022 (UTC)Reply

Oh that's very interesting, I have never seen the actual parameter values laid out like this.

However I don't really believe this touches on the issue at hand. Don't you think a page on the Telegrapher's Equations which doesn't include the Heaviside condition is incomplete? Not only is it of theoretical interest, but it drove actual design practice.

On the theoretical side, the Telegrapher's equations page is a page about a mathematical approximation. In this context, I still feel that it's important to indicate the Heaviside condition to a reader. Even if this condition is not practically achievable, the whole purpose of Heaviside's work was to identify the sources of dispersion, was it not? The reason that the Telegrapher's Equations exist was because Heaviside was interested in finding conditions under which the impediment to communication caused by dispersion might be addressed, as I understand it. Aren't we obfuscating the ultimate conclusion he reached, if we don't mention the condition he found?

On the practical side, I'm a design engineer myself, so I really do appreciate that you don't want a bunch of mathematically correct but practically useless garbage cluttering up a useful knowledge base like Wikipedia. But I don't think this falls under that heading. I haven't personally acquired a deep understanding of the details of practical transmission line theory (which is why I'm reading about it on Wikipedia), but I do know that people spent money on mu metal tape wrapping. It must have provided some benefit, and while I'm not a historian it seems like this approach was guided by an attempt to reach Heaviside's condition.

It feels like we can achieve both of our goals at the same time. I for one am just always curious what the theoretical answer might be even if the conditions are impractical, and whether approaching that theoretical answer might be useful. I think others might have the same curiosity. It seems like you want to make sure that useless, impractical crud doesn't clutter EE related pages, right?

The lossy section of the Telegrapher's Equations page could link to the Heaviside condition page, with a note that "practically speaking these conditions can't be achieved with actual transmission line materials, although attempts were made to approach them with added inductance provided by a wrapping of magnetic material around the conductor" or something like that. I volunteer to dig up some references to actual loaded transmission lines, and how close they approach (or don't) the Heaviside condition to support this qualification, if that would be helpful.

What do you think?

-InductorMan 157.131.205.57 (talk) 01:25, 7 July 2022 (UTC)Reply

Yes, I would like to see some references regaining loaded cable. You might want to look at [[1]] which has data on the 1928 submarine cable. Particularly look at figure 4, which shows the loading profile. The inductance ranges from 5.6 mH/nm (nm is nautical mile) in the unloaded end sections to 205 mH/nm in the maximally loaded middle section. That is a factor of about 37, or 1.5 orders of magnitude. That is about a factor of a million short of the Heaviside condition. But notice that they increased the inductance toward the middle of the cable. These guys knew what they were doing. They were optimizing the overall dispersion rather than trying to meet the Heaviside condition on particular sections. I don't know what method they used, but I strongly suspect that they used filter theory and treated the sections as lumped elements. Credit is due to the telegrapher's equations for telling them that they can treat the sections as lumped elements.

Here is a plot of the propagation velocity.

 

You can see that the benefit of the extra inductance is that it flattens out the velocity curve between 10 and 400 Hz which is where the cable operated. It also increased the delay, which was acceptable.

I regard the Heaviside condition as a mathematical curiosity, since L, C, G, and R are all functions of frequency. They also change with the daily temperature cycles. Interestingly, for modern dielectrics, G/ωC converges to the loss tangent of the dielectric for frequencies above about 0.1 Hz. The only way to operate in the Heaviside condition is to make R/ωL approach a constant. Since R already increases as the square root of frequency due to skin effect, you would need an inductance that decreases as the square root of frequency. It really is not feasible.

However, the for data cables, the secret to low dispersion is simple. Just make G/ωC and R/ωL small. In the coax chart above, that means anything above 1 MHz. No one attempts to increase inductance of cables today, because every method of increasing inductance requires some frequency dependent magnetic material and it increases delay. Today, what they are adding is air to the dielectric to make G and C as small as possible which reduces delay and attenuation. Dispersion is handled by adaptive equalization in the receiver.

The bottom line, for me, is pointing people to the Heaviside condition to explain dispersion is like pointing them to a blind alley. Constant314 (talk) 03:08, 7 July 2022 (UTC)Reply

I have to say I don't agree with this line of reasoning at all. I don't argue your point that uselessly simplified mathematical models are... well, useless. But I don't think it's even necessary to address this question, in order to answer the question of whether the link should be there or not. The link should be there because it's a core theoretical conclusion of the theory which forms the subject matter of the page.

The way I see it, the "Telegrapher's equations" page is a page about a particular mathematical model. And the Heaviside condition not only explains dispersion in this particular mathematical model, it is literally one of the sought-after results which inspired the creation of the telegrapher's equations in the first place. Did it solve the practical problem? I'm learning it did not. But was it one of the main answers which the equations sought to answer? I think so.

If you agree with the above statement, I really would strongly insist that the Heaviside condition should be linked from somewhere in the page, and with whatever kind of disclaimer you think necessary to accompany it. Absolutely let's exactly how practically useful or useless it is: that's even more valuable than just linking the theoretical solution alone. Or better yet let's link some solutions used in practice (which I have to say I'm unqualified to provide).

Obviously this is my subjective opinion. I'm not going to submit another edit if you feel the need to delete all such edits. But I would feel very frustrated to not be able to help others like me who were looking for this particular answer and had quite a lot of trouble finding it.

[edit: oh ps, thanks for the link! I actually found that last night, and skimmed that article! It looked really interesting, I was hoping to find some time to play around with the numbers as I see you already have.]

157.131.205.57 (talk) 02:14, 8 July 2022 (UTC)Reply

Contact me by email and I'll send you a spreadsheet of my guesses with regard to that 1928 cable.

With regard to the other, I think that you are committing synthesis (WP:SYN). That goes like this 1. Adding inductance moves the conditions toward the Heaviside condition, 2. They added inductance, 3. Therefore they were trying to meet the Heaviside condition. Conclusion #3 may be correct, but unless you have a reliable source that says that, then you can't put it in an article. You look at it and it looks like they were trying to achieve the Heaviside condition. I look at it and to me, they were trying to optimize a filter. If they even knew about the Heaviside condition, they had rejected it as being of no useful consequence. Neither statement can be put in the article without a reliable source that says that explicitly. Constant314 (talk) 04:16, 8 July 2022 (UTC)Reply

Ok, that sounds interesting, I will email you! I also wanted to ask you how you generated the velocity plot and where you got the data for loss tangent of gutta percha, but maybe that's best done over email. Now, I have to ask, how do I email you? Sorry I'm not really part of the Wikipedia community and don't know where to look for these things.

Regarding the link I want, I have to protest that I am making no such error as synthesis in my core argument. I believe it is you who are making an error with regard to the subject matter of the article in question. I hope this doesn't come across as antagonistic, that's not how I mean it. Bear with me and I'll explain what I mean.

Now, as far as the argument I made about the practical applicability of the Heaviside condition and loading telegraph cable, I admit I absolutely did say that it seemed like the practical addition of inductance might have been guided by the Heaviside condition. I agree that this isn't supported right now (and may be dead wrong), and can't be included in an article without references. This may have been an incorrect inference. We agree on this.

But let's please set aside the question of actual, designed, loaded cables and practical electrical engineering practice. We're required to set these topics aside to decide the question, because these things are not germane to the subject matter of the article. I will just excerpt the introduction of the article to remind us what we're talking about:

Telegrapher's equations

The telegrapher's equations (or just telegraph equations) are a pair of coupled, linear partial differential equations ... The equations come from Oliver Heaviside who developed the transmission line model ... The theory applies to transmission lines of all frequencies including direct current and high-frequency. Originally developed to describe telegraph wires, the theory can ...

Emphasis added. Now obviously I'm being selective here, but I'm trying to make a point. The point is that this is an article about a theoretical model, and I submit that what we are arguing about is whether one of the main mathematical results of the model should be mentioned or not.

Can we agree that this page is a page about a theory? Not about electrical engineering design practices? Or do you disagree with that? If you disagree, then I guess this argument won't go anywhere, and no hard feelings, I guess people have different perspectives.

But if I have convinced you that the page in question simply isn't a page about loading of telegraph cables, or design practice, or what real transmission lines do, and is in fact a page about a particular mathematical model called the Telegrapher's equations, then again I say there should be a link to the Heaviside condition. -InductorMan 157.131.205.57 (talk) 16:43, 8 July 2022 (UTC)Reply

Hi. I only have time for quick answers right now. I will write more, probably later today. To email, use the blue link on the left that says "Email this user". For information on gutta-percha see [[2]], table 1, specimen #3 in the power factor columns. Note, since G/ωC << R/ωL in the frequency range of interest, exact values of G are important. Constant314 (talk) 21:45, 8 July 2022 (UTC)Reply

I think that we have hit an impasse here. If you want to add the Heaviside condition to the article, you should probably make the case on the article's talk page. Maybe some other editors will agree with you. If you want to talk about the 1928 cable, I would be happy to continue that discussion. Constant314 (talk) 14:33, 9 July 2022 (UTC)Reply

Thanks again for the links, and I agree: we are at an impasse on the article link question. I do think I'll have more questions about the 1928 cable and cables in general, but first I'll need to digest what you've given me so far and get the email correspondence going. Thanks you for the helpful and courteous discussion. 157.131.205.57 (talk) 17:17, 9 July 2022 (UTC)Reply

I sent you the spreadsheet. Let's see if the attachment gets through. I meant to point you to this essay: WP:COATRACK. It is not an official guideline, bit a lot of us use it as such.

With regard to courtesy, I believe most editors are courteous, but some of them forget that written words often come out more forcefully than the same words spoken face to face in a friendly voice.

Welcome to Wikipedia! Constant314 (talk) 02:17, 10 July 2022 (UTC)Reply

Hello there,

you may have noticed that you reverted some of my edits about the Coloumb. Since I did have some sort of reason for them (mainly the superfluous detour in the definition), I'd be pleased if you could explicate in exactly what way you were bothered by what I wrote. Mathmensch (talk) 12:55, 21 December 2023 (UTC)Reply

Greetings, thank you for contacting me. I will try to get back to you sometime in the next 24 hours. Constant314 (talk) 13:44, 21 December 2023 (UTC)Reply

I most objected to this edit [3]. The original called out SI. You changed it to "Officially", leaving the reader to guess what official.

This edit [4] simply used more words to say the same thing without saying it better.

This edit [5] does not change the displayed text, but { {physconst|e|after=.}} tells the next editor more informaton than a simple number.

In this edit [6] "and expressions" is superfluous. Constant314 (talk) 13:46, 22 December 2023 (UTC)Reply

I see. I quite agree to all of your criticisms except for the very last: With your permission, I would keep the subtitle addition, because later in the section, more expressions for the constant are given. I would be grateful for some sort of feedback about this. Mathmensch (talk) 20:48, 23 December 2023 (UTC)Reply

I think that the section is about the definition. The fact that there are also expressions is incidental. But go ahead. Constant314 (talk) 23:37, 23 December 2023 (UTC)Reply

  Please do not introduce links in actual articles to user pages or sandboxes, as you did at Fourier transform. Since these pages have not been accepted as articles, user pages, sandboxes and drafts are not suitable for linking in articles. and such links are contrary to the Manual of Style. These links have been deleted, please do not re-add any such links, thank you - Arjayay (talk) 20:15, 31 December 2023 (UTC)Reply

@Arjayay: My apologies. Clearly an error on my part. That is not something that I would intentionally do. In fact, I don't even remember it. Finger spasm? Anyway, thanks for fixing it. Constant314 (talk) 23:21, 31 December 2023 (UTC)Reply

Can you please explain this [7]? If you had done a basic check you would have found this (which is linked to by the merge template) and this. You also only removed it from one of the two pages. Darcyisverycute (talk) 13:13, 5 January 2024 (UTC)Reply

My mistake. Reverted. Constant314 (talk) 14:33, 5 January 2024 (UTC)Reply

I would like to have the following added to Electromagnetic field as a sub topic what do you think. The great failure of Electromagnetic Theory

Electromagnetic Fields inability to explain how protons attract to protons was a major reason why many physicists moved away from EM theory in favor of Quantum theory to explain atomic structure.

No possible Electromagnetic Field around protons or electrons could possibly ever explain attraction between protons or why the electron was so noncircular in its motion.

Neutrons had no fields because they had no charge.

Obviously much has changed.

Protons are not stationary positive charges they are a stable composite particle made up of near light speed charges 2 positives and 1 negative. Similarly, neutrons are not stationary neutral particles they are composite particles made up of near light speed quarks as well; two negative charges and one positive charge.

Now, it is fairly simple to imagine how at much smaller distances super strong EM fields involving relativistic magnetic effects can begin to hold neutrons and protons together. However, the separate electric and magnetic fields must be abandoned in favor of a single actual field because the mathematical rules of magnetic flux make no sense when the particles move in tiny light speed circles.

Now we can begin to see how the proton and the neutron might produce EM field pulses which explain the electrons’ irregular orbital circular motion.

The motion may explain other effects as well which lead to restoring the EM field to an important place in the world of physics.

Bill field pulse (talk) 21:46, 18 January 2024 (UTC)Reply

If there is a great failure of Electromagnetic Theory, you need a reliable source that says that. Constant314 (talk) 03:25, 19 January 2024 (UTC)Reply

Many people do not seem to realize that the field around an electron and the energy that leaves it when it changes levels are different phenomena. I would like to add an article explaining the many ways they are so very different. What do you think? The article Quantization of EM Field is nonsense because the title is wrong to begin with. Bill field pulse (talk) 21:54, 18 January 2024 (UTC)Reply

Ultimately, the only content allowed in Wikipedia, is content that is paraphrased from a reliable source (WP:RS). We let a lot go by because it could be paraphrased from a reliable source. For example, "Paris is in France." I am pretty sure that if challenged, I could find a reliable source that says in effect that Paris is in France. If you add a fact to an article that is challenged, you need to be able to quote the passage from which the fact was paraphrased. The idea is simple. If an editor is reasonably proficient at reading and speaking English, he can compare your fact with the quoted material and verify (WP:VER) if you paraphrased correctly. That editor does not have to have any subject knowledge. He just needs to know the meanings of words. Of course, when there is jargon involved, he would need enough knowledge to understand the jargon.

Note, that I said paraphrased from a reliable source. That means one reliable source. You cannot get a bit here and a bit there to synthesize a fact. Nor can you depend on an inference or a conclusion. This can be extremely frustrating to a person who knows a lot but has limited access to reliable sources. I know, I bang against it all the time. But that is Wikipedia policy. We would rather miss important facts than take a chance on a false fact.

So, that is the first hurdle. You must have the reliable sources to unambiguously paraphrase.

Next, is it notable (WP:NOTE). Not every obscure fact is notable. Constant314 (talk) 01:03, 19 January 2024 (UTC)Reply

Well you did a fantastic job collecting the different points of view regarding what a field is to different experts. I think that this type of info belongs in the article the sources were valid, and Feynman did a lot for physics and deserves to have his perspective known.

I shall attempt to cite my university physics texts if it is deemed necessary. For example we all know charge is quantized. I could give the page and chapter where they say that but I trust I have correctly labeled that as obvious to all. Bill field pulse (talk) 19:43, 25 January 2024 (UTC)Reply

Yes, charge is quantized. NO argument there. Constant314 (talk) 01:27, 26 January 2024 (UTC)Reply

I see we disagree fundamentally whether a field is real or just a mathematical tool which works and also provides a way for local action between particles for those who need it. As you now see I am firmly in the group who believes that a charge changes the space beside it. I guess to Feynman all field like behavior is due to particle attributes. The electron and the quarks stick together because they stick together.

FYI my physical field is not infinitely rigid but much more rigid than ordinary objects (if you move a point on a stick to a precise location the rest of the stick follows around it but not as quite as quickly as the speed of light due to stretching, compressing and relativistic shorting of all the field in the atoms of the stick).

For one, like Feynman, who believes in forces at a distance without any link being required how do you see magnetism as occurring? To me it is the result of field compression in the direction of motion. Do you see it as a direct result of the charge movement?

Do you think the EM Field article should say: there are two opposing camps. One believes the field is a physical reality needed because they do not believe in action at a distance. The other that believes in action at a distance and only uses the field because the math works.

Note my physical field that is moving out at c, and compressible offers the chance to explain gravity and nuclear force. Your group already knows that gravitons cause gravity and gluons cause nuclear bonding. Bill field pulse (talk) 19:21, 25 January 2024 (UTC)Reply

You are welcome to discuss this with me on my talk page. Let's keep it here. Quondum has requested that we cease the discussion on the article talk page, which is intended for discussion aimed at improving the article, per WP:NOTFORUM. I feel that the discussion was a reasonable use of the talk page, but I don't feel like squabbling.

There are two words in use here that have somewhat fuzzy meaning: real and physical. The terms are not used consistently. For me, the classical EM field is real but not physical. It is real in the sense that the computed effects are real. Motors turn. The kettle boils water. Physical would mean that there is something there other than numbers. However, I accept that there may be something there that can be demonstrated by some experiment in the future. To date, there is not a shred of evidence that the field is anything but numbers. There is, however, a hypothetical experiment. Mass is equivalent to energy. If the field holds energy, then it should be able to deflect something by gravitational effect. The effect is so slight, that we have no idea how to conduct the experiment. But it is a future possibility.

There are not two camps. There are two sets of opinions. I have friends that believe there is no afterlife and friends that believe that there is. They have fundamentally different beliefs, yet they are all in the same camp. They work together, play together, dance together, even marry each other. That is the way it is on this issue. Feynman states that the field is real and composed of nothing but numbers. Jackson says the field is a mathematical function. Griffiths encourages you to think of the field as a real physical entity but cannot tell you what it is. Purcell says it doesn't make any difference whether the field is real or just a factor in an equation. Everybody uses the same theory which is nothing but a set on mathematical equations.

The article should be about the theory and not about people's beliefs. Constant314 (talk) 20:20, 25 January 2024 (UTC)Reply

The future experiment may never be possible because oscillating neutral waves from quarks produce nothing more than a wobble in a slow charge like an electron. The charge must speed up to match the wave in order so that its tiny field can add to the wave and only a very fast quark can do it.

I am committed to a physical reality. I did lots of diagrams of fields around things moving almost as fast as the field. I then estimated where the field was concentrated and tried to figure out how quarks would sit in those fields. Most lately i have a down leading up following quark pair in both the proton and the neutron having the largest radius (being fastest). My reason for gravity is the pair is pushed forward in the speed of light direction with less impact then back in the slowing down direct with normal effect. ie net pushback is gravity. Obviously, nothing theoretical like this can ever get into a theory article.

A slow charge can't get a net pushback because it can speed up a bit in the push forward.

Hopefully I have not made you change your mind we are all working in the same camp. Bill field pulse (talk) 21:48, 25 January 2024 (UTC)Reply

It does look like you are getting into WP:FRINGE, but we can still be friends.  :) Constant314 (talk) 00:41, 26 January 2024 (UTC)Reply

Great I can't ask for anything more thanks. Bill field pulse (talk) 18:37, 26 January 2024 (UTC)Reply

Do you have any good comments from experts in the difference between the field radiating out around all charges (quantized in magnitude) but continuous all around and Electromagnetic radiation which is a unidirectional quanta (only goes all around if a giant ball is producing photons all around) and no net EM field on stars just the radiation? Bill field pulse (talk) 19:06, 26 January 2024 (UTC)Reply

Of course not, because there is no difference. It is all photons. Constant314 (talk) 19:41, 26 January 2024 (UTC)Reply

what holds an electron to a proton in your model? (For me they move through each others real physical fields.) Bill field pulse (talk) 19:57, 26 January 2024 (UTC)Reply

I can only imagine a ball moving through a field as keeping in contact. Remember for me contact is needed . Bill field pulse (talk) 20:00, 26 January 2024 (UTC)Reply

Its like one of us believes in god the other doesn't for me it is hard to imagine as you see it. Bill field pulse (talk) 20:03, 26 January 2024 (UTC)Reply

I am afraid that I will have to go off on a tangent about the meaning of words. I hate to get into a long discussion and then find out we are using the same words with different meanings.

There is real stuff like rocks, H-bombs, tea kettles, and cold beer. There are real effects like falling down, getting warm in the sun, and hearing music come from a radio. The forces are real inasmuch as they are the names for the causes of real effects. The electromagnetic force is real. It energizes the lights. The sun heats us up. If I release a ball, it falls. The cause is gravity. It is real. I may not know what it is. We don't know how real stuff works.

Then there are theories about real stuff and real effects. There are entities defined within these theories that may or may not be real stuff. This includes photons, gluons, gravitons, fields, probability waves, and whatever mediates the weak force. I'll call them theoretical entities with the understanding that they might turn out to be real stuff. The nice thing about theoretical entities is we know exactly their definition, because we made them up. As we work with a theory, we may find inconsistencies. The inconsistencies may be resolved by redefining the theoretical entities or extending their properties.

When a theory works well, we tend to start forgetting the distinction between real and theoretical (but may be real) entities. We start believing that the theoretical entities are real stuff. Even if we do not forget, we often speak casually, So, if I say that all electromagnetic effects are mediated by photons, what I mean is that within the theory of quantum electrodynamics (QED), all electromagnetic effects are modeled as if mediated by photons.

If we talk about real stuff and effects, then we are talking about beliefs. Q: How does the tea kettle get hot? A: I believe that it is done by little elves.

Or we can talk about theories: Q: How does QED account for the tea kettle getting hot? A: It is accounted for by photon exchange.

Any comment? Constant314 (talk) 00:21, 27 January 2024 (UTC)Reply

On a heating element we have conduction where direct contact between kettle molecules and high energy element molecules makes it hard for elves to get their fingers in between, there is convection around the pot where gas is heated (perhaps elves make some of the gas hot and some of the gas is hot from contact with the element). Lastly, there is radiant heat which is all elves. Elves only appear when they are needed to persuade electrons to remember their place and stop causing trouble. Elves are very fast little critters and once they get going they will not stop till a very well behaved electron catches their attention. Now the elf wants the electron to show a little spunk move up a bit. As you can see elves just want to have fun bugging electrons. They are jealous of the beams which always hang with the electrons and never let them out of their sight. Most of the time it is electrons and beams. But if the electron gets too much anything an elf can pop up, or show up, disturbing the electron and his beam.

I don't mind calling them elves and beams but if you think is is all elves. There is so much proof of beams. If you think they are the same can't you see the little hats, the green shoes, I could go on and on. The beams are so very slight like tiny bubbles but once formed they never look back to them the electron has not moved and they just go on and on. The next beam has a new origin point and he does not care what the last beam thought or the next beam either he has his electron and he can't imagine it changing in any way. Every beam is like that they don't care where the electron goes. The beam remembers the electron as it was when they were together and he travels out to tell the world. But each beam is really connected so a new forming beam is always with the electron and the beam bubbles are theoretical so physicists cam see how beams evolves over time.

Don't you think we need to differentiate between the beam and the elf? Bill field pulse (talk) 20:22, 27 January 2024 (UTC)Reply

I can see that you have thought about it much more than I have. I always thought that the elves were extremely bored and made up this game that involves doing the wave, like crowd at a football stadium.

Oh, by the way, we have this church called C4F (Church of the Four Forces), or sometimes CFF. We had not decided on our three letter initials, but then some nonmembers registered both as domain names. Grrr. We haven't quite resolved our doctrine about the elves. But a whole bunch of them can dance on the head of a pin. Constant314 (talk) 22:34, 27 January 2024 (UTC)Reply

Thanks for the info. I will pass on this opportunity. Bill field pulse (talk) 18:49, 28 January 2024 (UTC)Reply

Hey, I stumbled across this trying to find something else. Excuse me for the late reply lol.

In integration rectangles are often used, and we don't stop using rectangles at the limit of ${\displaystyle f(x)}$  going to zero even if it is only a good approximation for area when ${\displaystyle f(x)>>dx}$  outside of which you maybe expecting the triangle-ish shapes to lead to inaccuracies. It only matters if the upper and lower limit converge to the same value. I won't try to rigorously talk about upper and lower limits in the context of the linked paper but I thought I had to comment since I feel like you left an interesting comment and took your time to go through my linked article. ^^ EditingPencil (talk) 20:31, 3 February 2024 (UTC)Reply

I'm going to wait a while and then make the same improvements to the EM field article again. When I do, you won't revert them. Holographer1 (talk) 19:47, 9 February 2024 (UTC)Reply

My apologies on reverting EM radiation. I had no issue with those edits. I was on the wrong article. Constant314 (talk) 19:49, 9 February 2024 (UTC)Reply

The discuss of physical vs mathematical needs reliable sources and a talk page consensus. When you change a stable article and get reverted, the onus is on you to build a consensus.

Apologize for my reverts on EM radiation. I was on the wrong article. Constant314 (talk) 19:52, 9 February 2024 (UTC)Reply

Regarding your revert https://en.wikipedia.org/w/index.php?title=Characteristic_impedance&oldid=prev&diff=1217577555 : I follow up on your revert comment "Already clarified in the same sentence. I'll be glad to help if you think I missed your intention.".

So the statement in the article as-is is the following:

> The characteristic impedance or surge impedance (usually written Z₀) of a uniform transmission line is the ratio of the amplitudes of voltage and current of a single wave propagating along the line; that is, a wave travelling in one direction in the absence of reflections in the other direction.

So I assue "already clarified in the same sentence" refers to "a wave travelling in one direction in the absence of reflections in the other directions".

This statement does not make it clear to me what a "single wave" is. The term "single wave" is still vague.

Exemplary suggestive questions that come here up are:

• is a single wave a single period?
• is a single wave a single frequency?
• is it a "packet of energy" / impulse?
• What makes a signal/wave a "travelling wave"?

Thank you very much with providing more insights, e.g. by further extending the explanation, by linking to a definite article, or by creating such article for "single wave". Abdull (talk) 09:35, 9 April 2024 (UTC)Reply

I see what you mean. I believe the intent of "single wave" means no wave traveling in the opposite direction. Constant314 (talk) 14:59, 9 April 2024 (UTC)Reply

I seemed to have welcomed someone at the same time as you - double welcome is not that common, it was accidental - I keep thinking there is lag somewhere to not have seen yours already there - feel free to delete mine if you feel inclined, otherwise... JarrahTree 02:12, 27 April 2024 (UTC)Reply

Nothing wrong with a double welcome. I am sure that there are lags. Nice to meet you. Constant314 (talk) 02:16, 27 April 2024 (UTC)Reply

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RamzyM (WMF) 23:18, 2 May 2024 (UTC)Reply

Hello. You recently put a tag requesting clarification on the Skin effect article. In your edit summary you said that you could provide illustrations if contacted. I am not terribly skilled in graphics programs, so I was wondering if you could produce an illustration similar to the one on the right. Here the ${\displaystyle \Delta a}$  length is perpendicular to to the long axis of the wire and the ${\displaystyle \ell }$  length is parallel.

Let me know if the description is unclear. Thanks, XabqEfdg (talk) 01:39, 7 May 2024 (UTC)Reply

That shows me what you want. I am not that good either, but this one looks pretty simple. Constant314 (talk) 02:21, 7 May 2024 (UTC)Reply

 

How is this? Constant314 (talk) 04:25, 7 May 2024 (UTC)Reply

Sorry for the delay in replying. That is excellent! Thank you for making that.

May I ask what used to produce such an image? XabqEfdg (talk) 14:43, 7 May 2024 (UTC)Reply

Thank you for the compliment. I use Microsoft Visio. I do not recommend it, but I have it and I am used to making it do what I want it to do. It is a 2D drawing program. It is tedious to 3D depictions. But I am retired and do not mind. I have posted the image. If you want different symbols or fonts or features, let me know. Constant314 (talk) 15:39, 7 May 2024 (UTC)Reply

Hi there. You reverted a small and useful cross reference I introduced in 1221518613. It looks like you tagged it as REFSPAM. My addition does not meet the definition of citation spamming in any why I can think of. If you think a different reference would be preferable, I'm happy to supply one. But I'd appreciate an explanation of this reversion. Thank you. Shonfeder (talk) 21:50, 8 May 2024 (UTC)Reply

My mistake. I had not noticed that you added a name to list. I apologize. Constant314 (talk) 22:35, 8 May 2024 (UTC)Reply

Ah, that explains it! Thanks for explaining, for undoing the erroneous reversion, and for spending time checking such things to maintain nice articles! Shonfeder (talk) 22:11, 9 May 2024 (UTC)Reply

Hello again! Sorry for messing up the per unit quantities in the derivation, but isn't the equation for voltage ${\displaystyle V=-\int _{d/2}^{D/2}E\cdot {\hat {r}}dr=-\int _{d/2}^{D/2}{\frac {Q}{2\pi \epsilon _{o}r}}dr={\frac {Q}{2\pi \epsilon _{0}}}\ln {\frac {D}{d}}}$  still incorrect? Since ${\displaystyle \int _{r}^{R}{\frac {dr}{r}}=\ln {\frac {R}{r}},}$  this would give a voltage of ${\displaystyle {\frac {Q}{2\pi \epsilon _{0}}}\ln {\frac {d}{D}}}$  since it's negative. It seems like either the bounds of the integral should be swapped or (equivalently) the negative sign should be removed. XabqEfdg (talk) 03:00, 10 May 2024 (UTC)Reply

Yes, it is possible that I have this backward. Let me ponder this for a bit. Constant314 (talk) 03:25, 10 May 2024 (UTC)Reply

@XabqEfdg: Potential increases when you push a positive charge against the E field. Assuming that there is positive charge on the center conductor, then the E field points from the center conductor toward the outer conductor. If you take the path of integration from inner to outer, you are going in the same direction as the field, so the change in potential would be negative. Based on that, it would appear that

${\displaystyle V=-\int _{d/2}^{D/2}E\cdot {\hat {r}}dr}$  is correct.

But, we want a positive number because we are just trying to compute capacitance. So, it would make sense to use either

${\displaystyle V=\int _{d/2}^{D/2}E\cdot {\hat {r}}dr}$  or ${\displaystyle V=-\int _{D/2}^{d/2}E\cdot {\hat {r}}dr}$ 

So, which is better? People are used to integrating from smaller to larger, but they are also used paths that start at ground which is usually the outer conductor.

I think I would choose ${\displaystyle V=\int _{d/2}^{D/2}E\cdot {\hat {r}}dr}$  as being simpler. Do you concur?

When I make this sort of computation, it usually works better for me to assume the center conductor is ground and the charge is on the outer conductor. Then ${\displaystyle V=-\int _{d/2}^{D/2}E\cdot {\hat {r}}dr}$  is correct, but the expression for E picks up a negative sign because E directed toward the center conductor. Whichever way we fix this, we should explicitly state where the charge is and which conductor is grounded.

I agree that your second option (smaller to larger) is better since the form is more easily understood and it doesn't matter if we integrate from inner to outer or vice versa, as long as the grounding and charge are defined so that voltage is positive. If we let the outer conductor be ground and the inner one be negatively charged, that will give a positive voltage integrating from the inner conductor to the outer one and keep the outer conductor as ground. Would that be acceptable? XabqEfdg (talk) 05:31, 10 May 2024 (UTC)Reply

To be sure, you want the charge on the inside of the outer conductor. If you aren't careful, you do get charge on the outside of the outer conductor, in which case it is a nice antenna. That is why you want the outer conductor to be ground. If you just want the integral to work, it doesn't matter, but if you are building something it does. Gah4 (talk) 10:41, 10 May 2024 (UTC)Reply

@User:Gah4. I just assume a grounded center conductor for analysis. Thanks for joining the discussion.

@XabqEfdg: I am pulled more than one way.

1. We should make it no more complicated than necessary. While I know exactly what you mean, most readers will not.

2. We should not say anything that is incorrect.

Since we are only trying to compute capacitance perhaps we should say that the magnitude of the voltage is given by ${\displaystyle V=|\int _{d/2}^{D/2}E\cdot {\hat {r}}dr|=|\int _{d/2}^{D/2}{\frac {Q}{2\pi \epsilon _{o}r}}dr|={\frac {|Q|}{2\pi \epsilon _{o}}}\ln {\frac {D}{d}}}$  Constant314 (talk) 13:13, 10 May 2024 (UTC)Reply

@XabqEfdg @Gah4 I had a nap! I see a simpler way to do this: just calculate C directly. I you have two concentric closely spaced cylinders of radius r separated by Δr then the capacitance per unit length is 2πrε/Δr. If we had more cylinders radially we just use the formula for capacitors in series. Thus

${\displaystyle {\frac {1}{C}}=\int _{d/2}^{D/2}{\frac {dr}{2\pi \epsilon r}}={\frac {1}{2\pi \epsilon }}\int _{d/2}^{D/2}{\frac {dr}{r}}={\frac {1}{2\pi \epsilon }}\ln {\frac {D}{d}}}$  Constant314 (talk) 16:27, 10 May 2024 (UTC)Reply

The solution with infinitesimal series capacitors would work, and you wouldn't have to talk about charge and grounding, but couldn't you just use that formula for capacitors which are not closely spaced? I.e. "using the formula for the capacitance of coaxial cylinders gives...".

If you were to use voltage and the definition of capacitance, I think the explanation with the magnitude of the voltage is OK, since that is what really matters in this case. XabqEfdg (talk) 16:53, 10 May 2024 (UTC)Reply

Yes, simply using the formula for coaxial cylinders was going to be my next suggestion. :) Of course, it is the same derivation. Likewise, characteristic impedance can be computed directly. Maybe we should just delete the derivation section and replace it with formulas from reliable sources. Constant314 (talk) 17:14, 10 May 2024 (UTC)Reply

That might be best. All the transmission-line specific information is already covered in "Important parameters", so all this is section would be doing is deriving coaxial cable inductance and capacitance. If people are interested, they can check the reference given or a many other physics textbooks covering inductance and capacitance, but I am not sure the derivations belong in the coaxial cable article. XabqEfdg (talk) 18:01, 10 May 2024 (UTC)Reply

Neither do I, per WP:NOTTEXTBOOK. Constant314 (talk) 18:09, 10 May 2024 (UTC)Reply

The formula for capacitance comes from doing the integral, though that might go to the capacitor article. I do remember, so many years ago, doing this for a physics lab. You can also get the propagation velocity from them. The lab I had, had a special cable with spiral wound, high inductance center conductor, giving about 0.1c velocity. It is meant for a delay line. The fun one, though, is that the velocity decreases at about the length of the unwound center conductor. That is, the speed of the wave following along on the helix. Derivation of the propagation velocity might go here. Gah4 (talk) 18:20, 10 May 2024 (UTC)Reply

See the new topic I added below this topic (might take e few minutes). Constant314 (talk) 18:33, 10 May 2024 (UTC)Reply

I used to work for a company that made handheld instruments for the phone company. It included TDR and insulation testing. Bellcore reps came out to review the product. They asked us to have a large spool of new telephone twisted pair cable available. We got a new spool. I think it was 500m of 7 pair cable with an overall shield. The nominal round trip delay is 10ns/m. So, we hooked up the TDR and sure enough there is a pulse at 5000 ns. The try open circuit, short circuit, resistor, etc. That return pulse does behaves exactly as expected. But there was also a pulse exactly at the halfway point (2500 ns). Everybody was going nuts, but since it was exactly halfway, I figured it was an artifact of the wire being on a spool. It is as if the pulse got to the far end and then took a short cut back to the beginning. e unspooled the cable and the mysterious pulse went away. The test was successful. I mentioned it to one of the Bellcore guys and he said that always shows up on new factory wound spools of cable. He said you just have to unwind the spool and then rewind it by hand. The spools coming from the factory are tightly and precision wound. Re respooled the cable and the pulse did not come back. I have not yet found an explanation.

Any guesses? Constant314 (talk) 19:45, 10 May 2024 (UTC)Reply

The physics lab I had, had spools of cable, though not factory wound. We had a pulse generator, series resistor, oscilloscope, spool of wire, and variable terminating resistor. That is, a poor-mans TDR. We measured the impedance by adjusting the terminator, and the attenuation by measuring the size of the reflected pulse. (Or maybe the size of the transmitted pulse.)

Your story reminds me of an Ethernet cable that mostly worked, but not quite as well as it should. So I was supposed to look at it. It seems that one end was mispaired. So one wire of one pair wasn't connected at one end, but one from another pair instead. You would think it wouldn't work at all, but there is enough coupling over the length.

Factory spooled cable has a nice layer wound in one direction, and then the next layer back again. It isn't so obvious, though, how the signal goes in that case. Gah4 (talk) 12:00, 11 May 2024 (UTC)Reply

OK, another coaxial cable physics story. In college, we had a demonstration showing the similarity between resonance in open and closed end air columns, like organ pipes, and open and shorted end coax cables. Sounds nice. In the middle of the demonstration, the demonstrator figured out something was wrong. The open end air column corresponded to the shorted end coax cable, and vice versa. That should have been fine. But the next class, the demonstration was back, this time with a current probe on the oscilloscope. Now it worked out: closed matches closed, open matches open. Most would have ignored the problem, or explained the reason. But we got the second demonstration. And of course, never forget it. Gah4 (talk) 12:08, 12 May 2024 (UTC)Reply

Makes sense. If you equate voltage to pressure and current to displacement, then a closed air column is equivalent an open-ended transmission line. The displacement at the end of a closed column is zero no matter how high the pressure. The current at the open end of a transmission line is zero no matter how high the voltage. Constant314 (talk) 15:01, 12 May 2024 (UTC)Reply

I might be close to answering your question, but another physics demonstration first. This one, as the story goes, by cowboys. First, the wave velocity on a taught string or rope, based on the tension (T) and mass/length (mu) gives velocity sqrt(T/mu). Next, centrifugal force is ${\displaystyle mv^{2}/R}$ . If you rotate a ring of rope, as the story goes a cowboy lasso, around its axis, the tension is ${\displaystyle T=\mu Rv^{2}/R}$ , or just ${\displaystyle \mu v^{2}}$ . If you distort the rope, such as kicking it, the distortion travels as a wave, both directions, with velocity v in the rotating frame, or velocity 0 and 2v in the non-rotating frame. Visually, so the story goes, you see the non-moving kicked dent, and not the fast moving 2v dent. Gah4 (talk) 11:07, 13 May 2024 (UTC)Reply

Ref. Ampacity. PeterEasthope (talk) 20:40, 17 June 2024 (UTC)Reply

I make a lot of edits. When you ask an editor about an edit, it is best to include the diff (the URL of the page showing the edit). Here is the diff for this edit diff

See WP:EL for general guidelines.

In this case:

• The link did not have any information that could not be added to the article.
• The link is to a commercial website full of product for sale. You can get around this if you can link directly to the useful information without seeing promotional material. For example, some manufacturers provide links white papers on a useful subject without seeing any advertising. Here is an example that would not be overly promotional: [8]. It does use the manufacturer's products for examples, but there are no offers to sell. It also has information that cannot be included in an article because of the length.
• The site is not a reliable source. See WP:RS.

Constant314 (talk) 21:09, 17 June 2024 (UTC)Reply

OK, thanks, ... PeterEasthope (talk) 15:45, 27 June 2024 (UTC)Reply

Thanks so much for looking over my proposed updates to the page awhile back. [https://en.wikipedia.org/wiki/Wikipedia_talk:WikiProject_Electrical_engineering#I_could_use_some_help_with_updating_ESAB] The Request Edits still haven’t been reviewed, even though I cut back the list from 8 to 4. Would you mind taking a look again and implementing these if you still think they’re reasonable? Request no. 4 is new since the last time you looked at these. Thanks so much for your time. Wiki-Free-Pie (talk) 20:52, 7 August 2024 (UTC)Reply

Yes, they still look good. I added a comment to the talk page that encouraged you to go ahead and make the changes yourself. I think you have completed the necessary due diligence. If you would message me when you are done, I will review them and comment. Constant314 (talk) 21:48, 7 August 2024 (UTC)Reply

We would appreciate it if you put the precession of equinoxes 2024 map back in the (Axial Precession) page where it belongs as it has everything to with that specific article. Sincerely Lion's the Tiger 2603:8001:1BF0:2200:58FC:19CB:57C8:E658 (talk) 20:04, 19 August 2024 (UTC)Reply

Hello. Thanks for contacting me. The best place to discuss this is on the talk page of the article. That way other interested editors can add their insight. When you add new material to an article that gets reverted, the next step is to start a discussion on the talk page. If you can achieve a consensus to add the material, then you can restore it.

In this particular case, I have a few objections.

• There are already good illustrations of the earth's axial precession in the article.
• The illustration appears to be the work of John K. Daley. Unless that is you, then you need to establish that you have permission from him.
• A single cycle of axial precession takes 26,000 years, so a 1-year map won't show much.
• If I don't understand it then the typical reader also won't understand it. This is my principal objection. Maybe your illustration is brilliant and shows a deep understanding that the other illustrators miss. If it is, then it worth having enough explanatory material to make it accessible to those of us who don't get it.

Constant314 (talk) 23:35, 19 August 2024 (UTC)Reply

Hi, I see that you reverted one of my edits on Electromagnetic radiation. Why is ThoughtCo an unreliable source?? Susbush (talk) 15:41, 25 September 2024 (UTC)Reply

I reverted my revert. Sorry for the inconvenience. Constant314 (talk) 01:24, 27 September 2024 (UTC)Reply

Hello @Constant314, It has come to my attention that you have reverted my edit to the Printed circuit board page without establishing any form of feedback or communication other than that of an indication of a “good faith edit”.

I will appreciate so feedback so I can make appropriate corrections to my original proposal.

Thanks Ekec.piw Ekecdnkoewihdouuepiw (talk) 15:02, 28 September 2024 (UTC)Reply

The feedback is in the edit summary: "Not encyclopedic." That could mean a whole lot of things. See WP:NOT. Sometimes I use that reason because it is vague enough to not hurt anyone's feelings. But I am always happy to discuss it in greater detail.

You added

• Circuit boards are typically designed by Electrical Engineers. They are heavily educated in advanced mathematics, physics and the underlying philosophy behind the interaction of often thousands of components within a complex circuit or several billion within an IC (integrated circuit) to develop a fully functional system. Electrical engineers possess at least a bachelor’s degree in Electrical and / or Electronics engineering with the latter specialising more in electronics in contrary to possessing additional expertise in extremely large electrical systems and passive components such as power grids or power transformers

Except for the first sentence, all of that is off-topic. What you wrote is about electrical engineers. This article is about printed circuit boards. Wikipedia articles need to be focused. If the reader wants to know more about electrical engineering, then they can follow the hyperlink.

The first sentence, "Circuit boards are typically designed by electrical engineers," is not correct. Circuit boards are typically designed by CAD operators with an associate's degree. Constant314 (talk) 15:51, 28 September 2024 (UTC)Reply