Practical talks by an astronomer by Harold JacobyPractical talks by an astronomer by Harold Jacoby

Practical talks by an astronomer

byHarold Jacoby

Paperback | February 4, 2012

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This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1902. Excerpt: ... Or NEBULA Scattered about here and there among the stars are certain patches of faint luminosity called by astronomers Nebulae. These " little clouds" of filmy light are among the most fascinating of all the kaleidoscopic phenomena of the heavens; for it needs but a glance at one of them to give the impression that here before us is the stuff of which worlds are made. All our knowledge of Nature leads us to expect in her finished work the result of a series of gradual processes of development. Highly organized phenomena such as those existing in our solar system did not spring into perfection in an instant. Influential forces, easy to imagine, but difficult to define, must have directed the slow, sure transformation of elemental matter into sun and planets, things and men. Therefore a study of those forces and of their probable action upon nebular material has always exerted a strong attraction upon the acutest thinkers among men of exact science. Our knowledge of the nebulae is of two kinds--" that which has been ascertained from observation as to their appearance, size, distribution, and distance; and that which is based upon hypotheses and theoretical reasoning about the condensation of stellar systems out of nebular masses. It so happens that our observational material has received a very important addition quite recently through the application of photography to the delineation of nebulas, and this we shall describe farther on. Two nebulas only are visible to the unaided eye. The brighter of these is in the constellation Andromeda; it is of oval or elliptical shape, and has a distinct central condensation or nucleus. Upon a photograph by Roberts it appears to have several concentric rings surrounding the nebula proper, and gives the general impressio...
Title:Practical talks by an astronomerFormat:PaperbackDimensions:44 pages, 9.69 × 7.44 × 0.09 inPublished:February 4, 2012Publisher:General Books LLCLanguage:English

The following ISBNs are associated with this title:

ISBN - 10:0217533078

ISBN - 13:9780217533072