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A featured text is one which is recognized as among the most complete and highest quality works on Wikisource. These are prominently displayed on the main page, inviting users to read at their leisure.


Featured texts edit
Date Text
2015
January The Russian School of Painting
February Diaries of Court Ladies of Old Japan
March The Problems of Philosophy
April On the Determination of the Wave-length of Electric Radiation by Diffraction Grating
May Kopal-Kundala
June
July
August
September
October
November
December
Notes
  1. The Black Cat was originally featured, but this is now a disambiguation page, and featured status has been transferred to Tales (Poe)/The Black Cat.

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"On the Determination of the Wave-length of Electric Radiation by Diffraction Grating" is an academic paper by Bengali scientist Professor Jagadish Chandra Bose, published in 1896 in Proceedings of the Royal Society of London (vol 60, no. 161).

The paper is an important work in the history of microwave optics and the invention of the radio. Bose himself, later Sir Jagadish Chandra Bose, was a pioneer in the field and has been named one of the fathers of radio science by the IEEE.

J.C.Bose.JPG

While engaged in the determination of the "Indices of Refraction of various Substances for the Electric Ray" (vide 'Proceedings of the Royal Society,' vol. 59, p. 160), it seemed to me that the results obtained would be rendered more definite if the wave-length of the radiation could at the same time be specified. Assuming the relation between the dielectric constant K and the index μ as indicated by Maxwell, to hold good in all cases, it would follow that the index could be deduced from the dielectric constant and vice versâ. The values of K found for the same substance by different observers are, however, found not to agree very well with each other. This may, to a certain extent, be due to the different rates of alternation of the field to which the dielectrics were subjected. It has been found in general that the value of K is higher for slower rates of alternation and the deduced value of μ would therefore be higher for slow oscillations, the longer waves being thus the more refrangible. The order of refrangibilities would in such a case appear to be somewhat analogous to that in an anomalously dispersive medium like iodine vapour.

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Flatland, a Romance of Many Dimensions is an 1884 satirical novella by the English schoolmaster Edwin Abbott Abbott.

Abbot intended his work as a critique on Victorian social hierarchy. Since its publication, however, it has been noted as an early piece of science fiction and, among mathematicians and physicists, for its examination of the concept of dimensions.

Flatland cover.jpg

I call our world Flatland, not because we call it so, but to make its nature clearer to you, my happy readers, who are privileged to live in Space.

Imagine a vast sheet of paper on which straight Lines, Triangles, Squares, Pentagons, Hexagons, and other figures, instead of remaining fixed in their places, move freely about, on or in the surface, but without the power of rising above or sinking below it, very much like shadows—only hard and with luminous edges—and you will then have a pretty correct notion of my country and countrymen. Alas, a few years ago, I should have said "my universe": but now my mind has been opened to higher views of things.

In such a country, you will perceive at once that it is impossible that there should be anything of what you call a "solid" kind; but I dare say you will suppose that we could at least distinguish by sight the Triangles Squares and other figures moving about as I have described them. On the contrary, we could see nothing of the kind, not at least so as to distinguish one figure from another. Nothing was visible, nor could be visible, to us, except straight Lines; and the necessity of this I will speedily demonstrate.

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Featured March 2012

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