A primary mirror (or primary) is the principal light-gathering surface (the objective) of a reflecting telescope.
Read more about Primary Mirror: Description, Superlative Primary Mirrors
Famous quotes containing the words primary and/or mirror:
“Wilful sterility is, from the standpoint of the nation, from the standpoint of the human race, the one sin for which the penalty is national death, race death; a sin for which there is no atonement.... No man, no woman, can shirk the primary duties of life, whether for love of ease and pleasure, or for any other cause, and retain his or her self-respect.”
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—“Jennie June” Croly 1829–1901, U.S. founder of the woman’s club movement, journalist, author, editor. Demorest’s Illustrated Monthly and Mirror of Fashions, pp. 24-5 (January 1870)