User:Chetvorno/work10

= Illustration of heading confusion = Talk:LC circuit

Heading 1 (2nd level)
It's clear that headings 2-6 are inside Heading 1 as the headings have different typefaces, but that is all that's clear. The font sizes of headings 2-6 are almost the same, so its hard to see how they are nested:

Heading 2 (3rd level)
Its clear that this is inside Heading 1

Heading 3 (4th level)
This heading is a subheading of Heading 2, but the font sizes are close so the reader needs sharp eyes to tell (without looking at the TOC)

Heading 4 (5th level)
This is inside Heading 3, but how would anyone know? The difference in font sizes is virtually imperceptible.

Heading 5 (4th level)
This is inside Heading 2 but not Heading 3 or 4. Do you think you could tell in a real article?

I'm going to space the next section apart from the others, as it would be in a real article full of text:

Heading 6
Okay, here's the test. Without looking at the TOC, which heading is this inside of?

Heading 7 (2nd level)
= For Music of Bulgaria = One of the most distinctive features of Balkan folk music is the complexity of its rhythms in comparison to Western music. Although it uses meters common in Western music such as, , and , Bulgarian music also includes meters with 5, 7, 9, 11, 13, and 15 beats per measure. Unlike Western music in which the accented or "stressed" beats occur at regular intervals in the measure, as in duple or triple meter, the stresses can occur asymmetrically in the measure, dividing the measure into different length subunits. These meters are often called "asymmetric meters".

For example, the popular dance lesnoto, widespread throughout Bulgaria, is done to music which has a meter of 7 beats, with emphasis on the first, fourth, and sixth beats: BEAT, beat, beat, BEAT , beat, BEAT , beat. Using the convention that each accented beat begins a rhythmic unit, the measure can be divided into three groups, a "slow" unit of 3 beats and two "quick" units of 2 beats, often written 3-2-2 or "slow-quick-quick".

Different folk dance families use different combinations of these rhythmic "units". Some examples are: rachenitsa (7 beats divided: 2-2-3), paidushko (5 beats: 2-3), eleno mome (7 beats: 2-2-1-2), daychovo (9 beats: 2-2-2-3), kopanitsa (11 beats: 2-2-3-2-2), and bucimis (15 beats: 2-2-2-2-3-2-2).

However, this division into "quick" and "slow" beats does not capture the full subtleties of Balkan rhythms. In addition to the primary stressed beats, other beats in the measure may have secondary stresses, and the rhythm stress pattern may change subtlely during the course of the music.

= For Wikiproject Electronics = The article Wireless power transfer has been a battleground for years due to extremely persistent efforts to insert an alternate theory that around 1900 Nikola Tesla transmitted electric power around the world using something called a Zenneck wave. This has been mentioned previously on this page: Fringe_theories/Noticeboard/Archive_44 The conflict is heating up again. Would be very helpful to have editors take a good long look at the recent Talk page discussion and express their opinion. Hope to have some editors watchlist this page and participate in future discussions, as there is little chance that it will end anytime soon. Thanks. -- Chetvorno TALK 03:48, 24 September 2016 (UTC)

= For Talk:Triode =
 * "On October 25th,...De Forest of the USA made his application for American patent of triode..." Okamura, History of Electron Tubes, p.97. "De Forest's triode was also called an Audion..." p.325  [Okamura continues to refer to De Forest's 1907 Audion as a triode many times.]
 * "De Forest invented the three-electrode valve or vacuum tube triode." Sarkar, History of Wireless, p.100. "This triode device he [De Forest] termed the "Audion"." (p.325)  "In the same year, Lee De Forest, the so-called Father of Radio, invented the transmission grid triode..." (p.335) Calling it a Three-Electrode Audion (patent issued on February 18, 1908), de Forest referred to it as a “device for amplifiing feeble electric currents”
 * "Without wishing to detract from the importance of the diode, it was the Audion - or triode - that revolutionized wireless..." Wood, History of International Broadcasting, p.9
 * "The year 1907 saw the invention, by Lee De Forest, of the first electronic device capable of amplification; the triode vacuum tube." Lee, Microwave Engineering, p.11
 * "...in 1906 - only three days, in fact, before he resigned from the company - he [De Forest] had conceived the first triode vacuum tube and given orders for its manufacture." Aitken, The Continuous Wave, Technology and American Radio, p.195. "The first public display of the triode audion was at a lecture before the Brooklyn Institute of Arts and Sciences on 14 March 1907" {p.222) [The text uses the term "triode audion" to distinguish De Forest's tube with the third electrode inside the tube from his earlier tubes with the third electrode outside, which were described on earlier pages.]
 * "In 1907-1908 American inventor Lee De Forest inserted a third electrode between the cathode and the plate. De Forest called his device the "Audion" but it is now called the triode"  Nahin, The Science of Radio, p.106
 * "The history of inventions is almost always clouded with claims and counterclaims and embellished with legend... So it is with the case of the thermionic triode, which Lee De Forest invented in 1906 as a detector of wireless-telegraph signals."   Robert Chipman, "De Forest and the Triode Detector", Scientific American, March 1965, p.93
 * "In 1907, he [De Forest] patented a much more promising detector which he called the Audion... It was a thermionic grid triode vacuum tube..."  Lee De Forest, Encyclopedia Britannica online
 * "Yet De Forest's trade name would disappear; in later years the Audion would be known as the "triode" because of its 3 internal elements" Morton & Gabriel, Electronics: Life Story of a Technology, p.8
 * "''De Forest... applied for a patent on October 25, 1906 for a "three-electrode valve..." He called his device the Audion. Thus the triode was created and the electronic era started..." Huurdmann, The Worldwide History of Telecommunications, p.226
 * "''In 1906-1907 De Forest introduced a third electrode, the grid... This triode, which De Forest called the "audion", not only rectified but also amplified the signal from the aerial. These early handmade valves contained a fair amount of gas and so varied in their working characteristics.  H. J. Round... and Robert Lieben... developed similar "soft" triodes.      Heilbron, The Oxford Companion to the History of Modern Science, p.819
 * "The audion was also called the triode" Hong,Wireless: From Marconi's Black Box to the Audion, p.223

= For Mirror =

Mirror image


In geometric optics the rule governing the operation of mirrors is Snell's "law of reflection", which states that the angle of incidence equals the angle of reflection. This means that a ray of light striking (incident on) a mirror will create a reflected ray which makes an equal but opposite angle with the surface normal, the line perpendicular to the mirror surface. The result of this is that light rays reflecting off a plane mirror from an object located in front of it create a virtual image of the object, reversed in the direction of the surface normal, which appears to be located an equal distance behind the mirror.

The law of reflection derives in electromagnetics from the boundary conditions of an electromagnetic wave incident on the mirror's conductive surface. Since the reflecting surface of a mirror is made of metal which is an electrical conductor, the electric field inside the metal is zero. Therefore the tangential component of the electric field $$E_t$$ at the surface of the metal must also be zero. Since $$E_t$$ is the sum of the tangential components of the incident $$E_{ti}$$ and reflected $$E_{tr}$$ waves must sum to zero and therefore must be equal and opposite: $$E_{tr} = -E_{ti}$$.

Another way to prove Snell's law is by using Fermat's principle of least time in optics. This states that a light ray always takes the path which minimizes its travel time. In mirror reflection, in which the entire path of the light is in a medium (air) with a constant index of refraction, this is the path of minimum geometric length. Of all the possible paths a light ray could take from point A to point B by reflecting off a mirror surface, the shortest one is the one which obeys Snell's law; that is, in which the angle of the ray striking the mirror is equal to the angle of the ray leaving the mirror.

Mirror image reversal


The image of an object in a mirror appears to be reversed laterally but not vertically; the left and right side of the image are reversed compared to the original object, but the top and bottom are not reversed. For example the image of a person in a mirror will appear to have his left and right hand reversed, but not his head and feet. The reason for this has been debated since ancient times; the first (erroneous) explanation was put forward by the philosopher Plato in the 4th century BCE in the dialog Timaeus, and Lucretius and Immanuel Kant

The issue was not fully resolved until 1997 by psychologist Richard L. Gregory in his book Mirrors of the Mind. See diagram, right. As Martin Gardner pointed out, a mirror does not actually reverse left and right any more than it reverses top and bottom. It reverses "forward" and "backward"; that is, in the image seen in the mirror the parts of the object appear reversed in the direction perpendicular to the mirror surface. Therefore an image seen in a mirror "faces" in a direction opposite to the object that created it. As a consequence, in order to compare an object with its reflection in a mirror, the object has to be turned to face the mirror. Alternatively, if the object is on the opposite side of the observer from the mirror (lower diagram, right), the observer himself must turn his head to face the mirror. Human beings tend to rotate things, as well as turn their own bodies, about a vertical axis; it is this rotation that causes the left-right reversal in the image. To turn an object to face in the opposite direction, it can also be rotated about a horizontal axis (turned upside down); if this method of reversing the object is used instead, the image will have top and bottom reversed, not left and right. This demonstrates that it is the type of rotation, not the mirror itself, that causes left-right reversal.

The reversal of a viewer's own image in a mirror stems from the same effect. To compare himself to his image in a mirror, a person must imagine walking behind the mirror and turning to face it, outward, in the same position as the image. Since humans turn about a vertical axis, this turn reverses his left and right sides, compared to the image he sees in the mirror.

History
Transmission of voice by radio waves was made possible with the invention of amplitude modulation by Reginald Fessenden and others around 1904. One of the first notable trials of "two way radio" was Lee De Forest's installation of arc radiotelephones on ships of the US Navy's Great White Fleet for its 1907 around the world cruise.

Talk
Agree the history section is completely erroneous. The Britannica cite is from an article on Motorola, which manufactured commercial mobile radios in the 1930s, but they were nowhere near the first. The first use of radio was two-way radiotelegraph communication around 1900. Two-way voice radio was achieved around 1904 by the invention of amplitude modulation, by Reginald Fessenden, Lee De Forest and others. One of the first notable trials was in 1907 when De Forest equipped the US Navy Great White Fleet with arc radiotelephones for their around the world cruise. The development of the triode vacuum tube 1907 - 1914 was what really made radiotelephony practical, and military two-way radio sets were developed during WW1. After the war the technology was applied to civilian uses, installed in police cars. Walkie-talkies weren't invented till WW2. I'll probably rewrite the history section, when I get some time.

= For Webopedia =

Webopedia.com is an online computer science and information technology dictionary based in Nashville, TN, USA. Founded in 1996, it is currently owned by Nashville web marketing company TechnologyAdvice. It's searchable database has about 4000 entries and is organized into hierarchical categories.

= For Talk:War of the Currents =


 * Stanley is an important contributor to the transformer. He created the design used for many years by Westinghouse, and their first parallel-wired transformer system. ([Reed, p.5-6).  His Great Barrington system went head-to-head with an Edison DC system and skunked it, an important win in the War of the Currents.(Klooster, p.306)(Welch & Lamphier, p.9)   But as you say he didn't invent the transformer, and ZBD were apparently making parallel AC power systems in 1985, a year before Westinghouse.   I guess I would support adding the phrase "in America" to the sentence:  "William Stanley used the Gaulard-Gibbs design and designs from the ZBD Transformer to develop the first practical transformer." --[[User:Chetvorno|Chetvorno]]TALK 01:00, 30 November 2023 (UTC)