{"id":1337,"date":"2023-12-04T15:25:19","date_gmt":"2023-12-04T15:25:19","guid":{"rendered":"https:\/\/live-optics-wp.pantheonsite.io\/oscoutreach\/?p=1337"},"modified":"2024-03-18T17:22:59","modified_gmt":"2024-03-18T17:22:59","slug":"making-telescope-mirrors","status":"publish","type":"post","link":"https:\/\/wp.optics.arizona.edu\/oscoutreach\/making-telescope-mirrors\/","title":{"rendered":"Making Telescope Mirrors"},"content":{"rendered":"\n

Overview<\/strong>: Making large telescope mirrors, called casting, is a very long and very precise operation. Taking the time to cast a mirror properly leads to clarity and resolution in telescopes that allow astronomers to accurately study the universe.<\/p>\n\n\n\n

Supplies:<\/strong> Turntable, flat bottom dish, water<\/p>\n\n\n\n

Objectives:<\/strong> Show how the rotational inertia of spinning a liquid can save mirror casters months of glass grinding by acquiring a rough initial mirror shape <\/p>\n\n\n\n

\n\n\n\n

Setup:<\/strong><\/p>\n\n\n\n

    \n
  • Fill the dish half way up with water<\/li>\n\n\n\n
  • Place the dish in the center of the platform on the turn table<\/li>\n<\/ul>\n\n\n\n

    How to run the demo:<\/strong> <\/p>\n\n\n\n

      \n
    • Point out the level of the water in the dish<\/li>\n\n\n\n
    • Turn on the turn table<\/li>\n\n\n\n
    • Watch the level of the water on the walls of the dish increase as the level of the water in the middle of the dish decreases<\/li>\n<\/ul>\n\n\n\n
      \n
      \n
      \"\"<\/figure>\n<\/div>\n\n\n\n
      \n
      \"\"<\/figure>\n<\/div>\n<\/div>\n\n\n\n
      \n\n\n\n

      What\u2019s Happening?<\/strong> <\/p>\n\n\n\n

      Large parabolic mirrors are made by a process called spin casting. The spin cast process starts by placing large chunks of glass in a special round furnace. The furnace heats up and melts the glass into a liquid. The furnace starts spinning and centripetal force pushes the glass out into a parabolic shape. The furnace continues to spin, while slowly cooling down. This spinning and cooling process allows the glass to keeps its shape.<\/p>\n\n\n\n

      \n\n\n\n

      Learn more:<\/strong> (external links)<\/p>\n","protected":false},"excerpt":{"rendered":"

      Water and a turntable shows the basics of making large telescope mirrors<\/p>\n","protected":false},"author":130,"featured_media":1338,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[7,8],"tags":[],"class_list":["post-1337","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-everyday-optics","category-physical-optics"],"_links":{"self":[{"href":"https:\/\/wp.optics.arizona.edu\/oscoutreach\/wp-json\/wp\/v2\/posts\/1337","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/wp.optics.arizona.edu\/oscoutreach\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/wp.optics.arizona.edu\/oscoutreach\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/wp.optics.arizona.edu\/oscoutreach\/wp-json\/wp\/v2\/users\/130"}],"replies":[{"embeddable":true,"href":"https:\/\/wp.optics.arizona.edu\/oscoutreach\/wp-json\/wp\/v2\/comments?post=1337"}],"version-history":[{"count":7,"href":"https:\/\/wp.optics.arizona.edu\/oscoutreach\/wp-json\/wp\/v2\/posts\/1337\/revisions"}],"predecessor-version":[{"id":1651,"href":"https:\/\/wp.optics.arizona.edu\/oscoutreach\/wp-json\/wp\/v2\/posts\/1337\/revisions\/1651"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/wp.optics.arizona.edu\/oscoutreach\/wp-json\/wp\/v2\/media\/1338"}],"wp:attachment":[{"href":"https:\/\/wp.optics.arizona.edu\/oscoutreach\/wp-json\/wp\/v2\/media?parent=1337"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/wp.optics.arizona.edu\/oscoutreach\/wp-json\/wp\/v2\/categories?post=1337"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/wp.optics.arizona.edu\/oscoutreach\/wp-json\/wp\/v2\/tags?post=1337"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}