How to make seven really large mirrors
November 25, 2017 2:36 PM Subscribe
Tucked under the east wing of the UA football stadium is the University of Arizona's Richard F. Caris Mirror Laboratory. Since 2005, they've been casting and polishing the giant mirrors for the Giant Magellan Telescope in Chile: each one's 8.4 m / 27′ in diameter. So, how do you build a mirror for one of the world's largest telescopes? Seemingly very slowly, while spinning.