Hello Reddit! We are excited to be here to share our expertise in the field of fabrication and testing of mirrors and other optical surfaces. Joining me (Dae Wook) in answering questions are my students Logan Graves and Isaac Trumper, who specialize in developing these types of measurement tools. We specialize in making very large telescopes of world renowned quality. We can do this only through understanding exactly how to make, and then test, the mirrored surfaces. You may have heard of one of our current projects, the Giant Magellan Telescope (GMT), but we like to call it a giant camera! This telescope is designed to investigate events just after the Big Bang, such as how galaxies formed. It will do an amazing job at collecting light in order to view very faint objects in the sky. We also work on other exciting projects such as a giant microscope (DKIST), and a giant action-cam (LSST). Please take a look at our group’s website to get an idea of the other types of projects we work on: http://www.loft.optics.arizona.edu/projects/. To enable these amazing telescopes, we develop fabrication and testing methods such as using silly putty to polish, or a TV and camera to display fun patterns to measure nanometer sized surface defects. We even use really hot wires to generate infrared radiation, which enables a whole different type of surface testing. Want to learn how you can make your own mirrors? Interested in amateur astronomy? Want to understand how optics and light works more? Well then come on and ask us anything! We will be back at 6 pm ET to answer your questions, ask us anything! Edit: Hello Reddit, we are live! Edit: Hello Reddit, we are leaving for now and will come back later for some follow-ups if there are any more questions/comments. We enjoyed it! Thank you.