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umbra |
Also found in: Dictionary/thesaurus, Wikipedia, Hutchinson | 0.06 sec. |
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umbra: see eclipse eclipse (ēklĭps`, ĭ–) [Gr. ..... Click the link for more information. ; sunspots sunspots, dark, usually irregularly shaped spots on the sun's surface that are actually solar magnetic storms. The Chinese recorded dark features on the sun seen with the naked eye in 28 B.C. ..... Click the link for more information. . umbra 1. a region of complete shadow resulting from the total obstruction of light by an opaque object, esp the shadow cast by the moon onto the earth during a solar eclipse 2. the darker inner region of a sunspot umbra [′əm·brə] (astronomy) The dark, central region of a sunspot. (optics) That portion of a shadow which is screened from light rays emanating from any part of an extended source. How to thank TFD for its existence? Tell a friend about us, add a link to this page, add the site to iGoogle, or visit webmaster's page for free fun content. |
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De umbris, in Bruno, 1879-91, 2:1, 38-39: "Adest paradigma unius ideae actu infinitas rerum differentias habentis, et unius umbrae in facultate infinitarum differentiarum. Lambert, Photometria sive de mensura et grabibus luminis, colorum et umbrae, Eberhard Klett, Augsberg, Germany (1760). Esse autem rationales animas sphaeras quasdam spiritales, et circuitum in seipsis facere spiritalem, postquam corpora ipsa quae illarum umbrae sunt, figuram talem habent et motum. |
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