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#11
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#12
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![]() jaro, Sort of like what you are doing? Art drew one conclusion from Peter's post. I supplied another. What's your problem? 'Doc |
#13
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The so called experts are really screwing around to provide
a platform to show off there learned minds instead of sticking to basics Art Their you go! Wuold the rael epertxs santd up and sictk to biascs? Bdaa BUm |
#14
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Art:
[snip] "Art Unwin KB9MZ" wrote in message m... But Peter you said something about changing a model What was that all about ? Regards Art [snip] What I meant is that there is the "real world" and its' behaviour as evidenced by experiment and measurement and then there are "models" , i.e. theories or mathematical constructs which humans have devised to "imitate" or "model" the "real world". When considering accuracy and precision whenrepresenting real experiments and measurements models that attempt to reflect real world performance over time have come in various stripes. In the history of electro-dynamics there have been three major models/theories developed in three eras over the last couple of hundred years. (I) Circuit-Theoretic Model Era (circa: 1750 - 1850): The first model/theory of electro-dynamics was the "circuit-theoetic" model which used the circuit theory of Messers Kirchoff and Ohm, developed in the late 1700's and the early part of the 1800's . Kirchoff's Laws and Ohm's Laws for DC circuits ultimately supported by Heaviside's operational calculus in the mid 1800's to reflect both DC and AC phenomena. [Heaviside invented the terms reactance, and impedance, etc.] But experimentalists and the "electricians" of the day found that circuit theory models did not predict everything exactly! All that said, the circuit-theoretic electro-dynamic model is pretty simple and accessible to anyone with a modicum of mathematical background, say the equivalent of high school algebra and complex numbers. Sorry... but if you can't do simple algebra, deal with the square root of minus one, and manipulate complex numbers then circuit-theoretic models are not your cup of tea. Get off the train here and go into marketing or the social sciences! :-) Circuit theory does a pretty good job of predicting lots of things, but it fails to predict effects such as skin effect, proximity effect, radiation, etc... And so the electro-dynamic model was eventually augmented by a newer model which was more accurate reflects reality more closely. The second stage of the three eras of electro-dynamic theories was the: (II) Field-Theoretic Model Era (circa: 1840 - 1910): The "field-theoretic" model was first formulated the famous Scottish theoretical physicist James Clerk Maxwell, and rendered in its' modern form by the eccentric, uneducated, self-taught English genius Oliver Heaviside. Heaviside wrote down Maxwell's extremely complex theory in the form of four simple vector differential equations as we now know them. Whilst previously it had taken the Cambridge educated Maxwell 22 quaternion laced equations to write down the same simple theory! Heh, heh... Of course Heaviside, a denzien of the London slums, who never went to school beyond age 16, had the advantage of "simplicity-of-thought" over the Cambridge educated Maxwell. All that said, the field-theoretic model is considerably more complicated than the circuit-theoretic model and is only accessible to those prepared to go beyond high school algebra and complex numbers into the calculus of vector differential equations. Sorry but if you are not prepared to go there, as the sixteen year old poor boy from the slums of mid 1800's London did, then field-theoretic modeling is not your cup of tea, and you need to go into marketing or the social sciences... :-) Field theory is more complicated than circuit theory but it does a pretty good job of predicting all that circuit theory predicts plus a lot of other things, such as skin effect, proximity effect, radiation, etc... but even field theory fails to predict the photo-electric effect, and other interactions of photonic energy and matter, etc... And so the electro-dynamic model had to be expanded yet again, this third (and final) theory is called QED or Quantum Electrodynamics. (III) Quantum-Theoretic Model Era a.k.a. QED (circa: 1900 - 2000) The quantum-theoretic model was initiated by Einstein in the first decade of the 1900's to explain the photoelectric effect and was further developed by Pauli, Dirac, Schrodinger, Planck, and many others and ultimately "simplified", in the Oliver Heaviside style, by one Richard P. Feynman from the Bronx, NY who also dramatically exposed the cause of the Challenger tragedy with a glass of ice water. For these efforts "Albert" was awarded the Nobel prize. One can only presume that the Nobel committee did not feel that the Theory of Relativity a.k.a the "Ultimate Theory of Gravitation", was worth the prize! Although they did award the prize to that Italian ham radio operator Guglielmo Marconi! What? :-) Now the mathematics needed to access QED is considerably more complex than that needed for circuit theory (Algebra and Complex Numbers), field theory (Algebra and Complex Numbers plus Vector Calculus and Vector Differential Equations). Indeed to access QED models one needs to understand all of the aforementioned plus the mathematical Theory of Probability and the Theory of Groups, Rings and Ideals. If you are not prepared to go there, as that poor boy named "Richard" from the Bronx was, why then QED is not your cup of tea and you should get off the model train now and take up marketing or the social sciences... :-) It seems today that QED models encompass all prior models and fully explain all known electro-dynamic phenomena and that mankind does not require further models to augment those at hand to predict electrodynamic reality. I wonder? All that said... this does not mean that QED has displaced field-theoretic and circuit-theoretic concepts and models. Indeed circuit-theroretic and field-theoretic models are more widely used today than ever before! Indeed circuit-theoretic models and field-theoretic models are used daily by Engineers and scientists (Note the capitalization!) on a daily basis. [Engineers make things people need out of stuff they can get, while scientists... :-)] Indeed the mathematics and mechanisms of QED and field-theory are much to complicated and unecessary to make efficient modeling of phenomena that are quite adequately described by circuit theory. Hence the very popular SPICE computer programs, originally developed, with US Taxpayer support, at UC Berkeley in California and widely available for free download, which are used everywhere today to design both discrete and integrated electronic circuits from modern Op-Amps to Pentium processors uses the century and a half old circuit-theoretic models. For an excellent free version of SPICE download LTSpice from the Linear Technology Corp. web site at: http://www.linear.com/software/ and run circuit-theoretic models to your heart's content, just don't use SPICE codes to design antennas or predict the skin effect! :-) Oliver Heaviside would quickly recognize the SPICE program flow charts and computer codes were he alive today! But circuit theory is not complex enough to solve antenna and radiation problems or skin and proximity effects and so one needs access to models and computer programs that solve the partial differential vector equations of the Maxwell-Heaviside field theory. Hence the very popular, US Taxpayer supported, NEC computer program codes were developed at Lawrence Livermore Labs, also available as free downloads. Our own Roy Lewallen W7EL provides his EZNEC programs based upon the free NEC codes for a modest fee. Download Roy's free demo of EZNEC at: http://www.eznec.com/index.shtml and run field-theoretic models to your heart's content, just don't use it to design photoelectric sensors or Pentium processors! ;-) Finally if you really need to go there... There are plenty of QED computer programs available, also widely supported by the US Taxpayers, just google... An Engineer is a person who knows reality and knows her models, and she... "knows whento hold them and when to fold them". She uses them to design and build things that people need out of stuff that she can get. Don't forget to thank the, often vilified, US Taxpayers for their unwavering support of the development of all of the free computer program implementations of circuit-theoretic, field-theoretic and QED models with the computer programs called SPICE, NEC and other QED kinda stuff... Happy Holidays, y'all! -- Peter K1PO Indialantic By-the-Sea, FL Hey... "surf's up"! |
#15
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Peter K1PO among other wow stuff:
[Engineers make things people need out of stuff they can get, while scientists... :-)] ....take a free ride, write the papers, get government grants, fancy titles, give engineers hard time by nitpicking on 0.00001, and .... :-( In Europe engineers get to use the title Ing. or Dipl.Ing. to indicate that they completed studies and are working on improving the tools for mankind. In Canada they use P.Eng., here in Hamerica they are the best kept secret, underpaid, overworked, oversued. Just look at Nikola Tesla or ask any student. Who? What? Yuri :-(da ridiculed peng)-: |
#16
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Yuri:
[snip] In Europe engineers get to use the title Ing. or Dipl.Ing. to indicate that they completed studies and are working on improving the tools for mankind. In Canada they use P.Eng., here in Hamerica they are the best kept secret, underpaid, overworked, oversued. Just look at Nikola Tesla or ask any student. Who? What? Yuri :-(da ridiculed peng)-: [snip] So you are saying that Engineers are the Rodney Dangerfield of American society! Yep, I do believe that you are correct. First manufacturing and then Engineering follows... it's getting worse over here year by year with more and more "high tech" Engineering work being done by our far eastern brothers and less here in the West. Each year the next generation of Engineers I see graduating from our schools seem to exhibit less and less knowledge and skill. It happened with consumer electronics and ham radio equipment lo these many years ago today it is software development and soon "all" Engineering will be gone from the West. Eventually there will be no more Engineers in the West who understand technology, just a bunch of "technology operators" with great social science and marketing skills operating the video games of life! Only be a few of us old-time "antenna gurus" will recall when and how the A/D and D/A converters got put on the outside of the antenna connectors on our SDR's!!! And... all the rest will olny have Art Uwnin explagnini to htem woh thigns wrk. Not a pretty picture! ;-) -- Peter K1PO Indialantic By-the-Sea, FL |
#17
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Peter O. Brackett wrote:
And so the electro-dynamic model had to be expanded yet again, this third (and final) So far, :-) theory is called QED or Quantum Electrodynamics. -- 73, Cecil http://www.qsl.net/w5dxp -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
#18
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.... snip sinp
Not a pretty picture! ;-) -- Peter K1PO Indialantic By-the-Sea, FL Right on Peter, Maybe time for engineers to get into politics, replace lawyers and dumb politicians in running the country. Get some sanity into governing because it doesn't look too promising. Seeing dummycRATS spewing venom at president with loud support from the "media", brainwashing illiterates just doesn't look so good. I hope that country is being pushed to the extreme only to kick back and shake the liberal commie establishment back to the caves. 73 Yuri |
#19
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Dear Peter:
I would have sent this to you privately, but you do not provide a valid E-mail address. Well done on presenting the sequence of understanding and emphasizing the role of mathematics. In "Hamerica" some real Engineers are P.E.s. It is not just for Canadians. 73 Mac N8TT -- J. Mc Laughlin - Michigan USA |
#20
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