What is a Liquid Mirror Telescope?
In principle, an LMT is no different from a normal reflecting telescope. Check How Telescopes Work for a thorough explanation of telescopes. Here’s a quick recap. A reflecting telescope uses mirrors to view distant objects. A primary mirror gathers light from the object, while a secondary mirror focuses the image to the eyepiece. In a conventional reflector, the primary mirror is made by painstakingly grinding and polishing glass to its desired shape, usually a parabola. Once the glass is prepared, a process known as aluminizing makes it reflective. Aluminizing involves vaporizing aluminum in a vacuum, causing a film of metal about 100 nanometers thick to be deposited on the glass. Flaws in the mirror production can affect how the telescope performs. This was the issue with Hubble: The curve in its primary mirror was off by just a fraction of a hair’s width, which caused light to reflect away from the center of the mirror, leading to blurry images. Photo courtesy of NASA A 3-meter LMT
