4 ms·
Its not your normal soda-lime glass, its more of a glass-ceramic material that have very low coefficient of thermal expansion, something like zerodur: https://e
by minetest2048 1y ago
Its not your normal soda-lime glass, its more of a glass-ceramic material that have very low coefficient of thermal expansion, something like zerodur: https://en.m.wikipedia.org/wiki/Zerodur https://en.m.wikipedia.org/wiki/Zerodur , which means it can keep its shape and focus even under varying temperature
Interesting demo by Huygens Optics: https://youtu.be/qi8jmEbWsxU?si=rj0I3k-l74Xhg7vC https://youtu.be/qi8jmEbWsxU?si=rj0I3k-l74Xhg7vC
- perihelions 1y agoI think while the smaller mirror here is Zerodur, the larger one is just borosilicate, https://astro.arizona.edu/news/rubin-observatory-achieves-another-major-milestone-reflective-coating-84-meter-primarytertiary https://astro.arizona.edu/news/rubin-observatory-achieves-an...
- IAmBroom 1y agoThat would be an odd choice. A large glass mirror once cracked because they "only" allowed one year for it to cool. The second one was allotted three years.