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Re: SWR vs. Resonance


 

Since we¡¯re having do much off-topic fun, I offer the following for you history buffs:

So, Hertz begins his work on the first experiments 13 Nov 1886.

He finishes up his first experiment to meet the publishing deadline for Wied Annalen on
25 March 1887.

Wied Annalen XXXI is published on 15 May 1887.

Oliver Lodge reads about it on the train to the British Association Meeting in Bath 1888, all set to give a talk on lightning rods and rf transmission and resonance and such, and hears Fitzgerald introduce the topic at the meeting¡¯s inaugural address on September 6, 1888.

Lodge gets even more excited (excuse the pun) and puts forward a new paper on Hertz'
work to the Physical Society of London May 11,1889, taking issue with Hertz' calculations on capacitance, suggesting Hertz missed that there were really (effectively) two 30 cm diameter spheres in series (P. 151), given the potential of one sphere at +V
and the other at -V potential, and that the capacity would be 7.5 cm vs Hertz' 15 cm
capacitance.

He also quibbles about Neumann's formula. Lodge concludes his addendum of June (P.162) with a repeat of having caught Hertz' capacitance error, and takes a shot at the French/German use of period T between nodes conflicting with the English use of period T being one full cycle, and writes:

There is one point on which we find ourselves differing from Hertz...in the application a 2 or a sqrt2 comes in wrongly in one or other of our
calculations....and it must be that it is owing to a different calculation of the effective capacity concerned in an oscillator that the discrepancy arises.

This discrepancy we by no means view lightly, and it is not without many qualms that
we find ourselves differing, even about a 2, with a man so splendidly careful in
his work as Hertz has shown himself.

Lodge (humbly or tongue in cheek) ends with:
It is more than probable that he [Hertz] is right after all, so we explain here what will then
turn out to be our error in this note.

The Physical Society refers the article to Philosophical Magazine, and it is published in
Vol XXXI on July 1889.

Various correspondence ensues between Fitzgerald and Hertz, and likely Lodge and
Hertz over the next year.

Across the Channel, Poincare reads of the experiment, and on 15 August or so 1890
(three years after the publication in Wied Annalen XXXI) writes to Hertz that he
(Poincare) has written to the Academie des Sciences de Paris about the experiment,
advising the Academie Hertz' having overlooked the series capacitance of the two
spheres.

Poincare's paper is picked up Comptes Rendu Volume 111 August 1890 and Archive des Science.

Hertz writes Poincare back 21 August 1890 with what must have been an
understatement:

L'erruer que vous avez decouverte est une veritable erreur assez desagreable.

[The mistake you have discovered is a real mistake that is quite unpleasant.]

Hertz adds that he'd been away for several weeks from his papers, but that he had
already seen news about his calculation error written by Oliver Lodge published
somewhere (maybe The Electrician or Nature), i.e., thanks Henri, already have the bad
news, but thanks anyway.

Correspondence begins between the two that leads to discussion of the Sarasin and de
La Rive verification in Geneva of Hertz' works in a larger lab, with the beginnings of an
explanation of multiple resonances phenomena for which Hertz had no immediate
solution.

Not to be scooped by Lodge, Poincare publishes in early 1891 his text Electricite et
Optique II: Les Theories de Helmholtz et Les Experiences de Hertz, which includes
lessons taught by Poincare during the second semester 1889-1890, noting Hertz
overlooked the correct calculation for the system capacitance.

By the time the 1894 English translation and faithful reproduction of the original Hertz
collection of the 1891 Collection of Wied Annalen articles is published the English
edition (Jones) includes an Introduction from Hertz and Supplementary Notes to the
original articles that, in 1894, addressees the capacitance error, multiple resonances,
and various other challenges, as well as the positive outcome of the Sarasin and de La
Rive experiments in Geneva.

Heaviside, in the meantime, on the basis that his ¡°new math¡± works, becomes accepted.

Great stuff.

And how they communicated without texts and tweets and such, editing for letters and the next publication of technical papers, that appeared without links to or ads to the next wonder Balun or OCFD!!

Thought you might find this interesting.

Ed McCann
AG6CX

On Oct 16, 2024, at 9:09?AM, Ron na2o via groups.io <groups.io@...> wrote:

?On Wed, Oct 16, 2024 at 12:00 PM, W0LEV wrote:

"off-topic digressions"

Yeah, maybe. But fascinating stuff & worth every minute of it. IMO

--
Ron na2o




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