LT-SEM snow crystal magnification series-3

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Created by Brian0918 from images at: http://www.anri.barc.usda.gov/emusnow/Magnification/Magnification.htm

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https://dkwiki.dk/b/3f32

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Wikimedia Commons

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900 x 3994 Pixel (1568917 Bytes)

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Low temperature scanning electron microscope [1] magnification series, from 93× to 36,000× magnification series, of a snow crystal. Most samples of snow crystals are observed by researchers at relatively moderate magnifications (30×–500×), however the capabilities of the electron microscope allow observation of fine structures at over 100,000×. The following set of photographs demonstrates a magnification series using a low temperature scanning electron microscope (LT-SEM) covering this range. By contrast, the light microscope is only capable of viewing meaningful details at magnifications of about 1,000× and is very limited in depth of field. Snow samples are very fragile and exposure to the light necessary to photograph them, using light microscopes, can change structures and even melt them. Using LT-SEM, samples are frozen to temperatures below −170 degrees Celsius where they can be placed in a vacuum and observed for many hours with no structural changes. These photographs show the extraordinary symmetry of snow crystals even at high magnification. Magnification bars are accurate but X factors (lower left) are for 8"×10" prints.

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Public domain