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. 1852 Excerpt: ...to elude the most delicate observations. A very different method has been devised by M. Arago for ascertaining the nature of the light by which comets shine. It is well known that when light is reflected from a body at certain angles, it acquires properties different from those which characterize light emitted directly ...
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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. 1852 Excerpt: ...to elude the most delicate observations. A very different method has been devised by M. Arago for ascertaining the nature of the light by which comets shine. It is well known that when light is reflected from a body at certain angles, it acquires properties different from those which characterize light emitted directly from a self luminous body; or, in other words, the light thus reflected becomes polarized. By means of experiments on the light of the comet of 1819, M. Arago found that it contained polarized, and therefore reflected light. Similar experiments on Halley's comet, made on the occasion of its apparition in 1835, afforded still clearer indications of the existence of reflected light f. In other instances, as in the case of the great comet of 1843, no trace of polarized light was discernible J. It may be remarked that experiments of this nature, however unequivocal their results may be, are not capable of deciding the question with respect to the nature of the light by which comets shine, since a body, although self luminous, does not with less facility on that account reflect the light of other bodies. There is a question of another kind, however, upon which such experiments are calculated to throw a decisive light. It has been mentioned as a proof of the translucency of the matter of which comets are composed, that the smallest stars have been occasionally seen through them without undergoing any diminution of lustre. This, however, has not been the invariable result that has occurred, under such circumstances, to the observation of astronomers. In some instances the star has appeared sensibly fainter from the interposition of the comet. For example, on the 31st of October, 1807, Sir William Herschel found that small stars, seen through the tai...
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Add this copy of History of Physical Astronomy: From the Earliest Ages to cart. $87.52, good condition, Sold by Bonita rated 4.0 out of 5 stars, ships from Newport Coast, CA, UNITED STATES, published 2008 by Kessinger Publishing.
Add this copy of History of Physical Astronomy: From the Earliest Ages to cart. $88.07, good condition, Sold by Bonita rated 4.0 out of 5 stars, ships from Newport Coast, CA, UNITED STATES, published 2010 by Kessinger Publishing.
Add this copy of History of Physical Astronomy: From the Earliest Ages to cart. $108.85, good condition, Sold by Bonita rated 4.0 out of 5 stars, ships from Newport Coast, CA, UNITED STATES, published 2010 by Kessinger Publishing.
Add this copy of History of Physical Astronomy: From the Earliest Ages to cart. $108.85, good condition, Sold by Bonita rated 4.0 out of 5 stars, ships from Newport Coast, CA, UNITED STATES, published 2008 by Kessinger Publishing.
Add this copy of History of Physical Astronomy: From the Earliest Ages to cart. $125.14, new condition, Sold by Bonita rated 4.0 out of 5 stars, ships from Newport Coast, CA, UNITED STATES, published 2008 by Kessinger Publishing.
