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:

    A fact is a proposition of which the verification by an appeal to the primary sources of our knowledge or to experience is direct and simple. A theory, on the other hand, if true, has all the characteristics of a fact except that its verification is possible only by indirect, remote, and difficult means.
    Chauncey Wright (1830–1875)

    A man has only one escape from his old self: to see a different self—in the mirror of some woman’s eyes.
    Clare Boothe Luce (1903–1987)