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:
“If a madman were to come into this room with a stick in his hand, no doubt we should pity the state of his mind; but our primary consideration would be to take care of ourselves. We should knock him down first, and pity him afterwards.”
—Samuel Johnson (1709–1784)
“The barriers of conventionality have been raised so high, and so strangely cemented by long existence, that the only hope of overthrowing them exists in the union of numbers linked together by common opinion and effort ... the united watchword of thousands would strike at the foundation of the false system and annihilate it.”
—Mme. Ellen Louise Demorest 1824–1898, U.S. women’s magazine editor and woman’s club movement pioneer. Demorest’s Illustrated Monthly and Mirror of Fashions, p. 203 (January 1870)