Primary Mirror

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:

    Without the Constitution and the Union, we could not have attained the result; but even these, are not the primary cause of our great prosperity. There is something back of these, entwining itself more closely about the human heart. That something, is the principle of “Liberty to all”Mthe principle that clears the path for all—gives hope to all—and, by consequence, enterprize [sic], and industry to all.
    Abraham Lincoln (1809–1865)

    The creation of “strong-minded” women, so-called, is due to the individualism of men, to the modern selfish and speculative spirit which absorbs everything within itself and leaves women nothing but self-assertion for their protection and support.
    “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, p. 44 (February 1870)