Advantage is that it's lighter, but thin mirrors distort images less and have a lesser weight. If the mirror isn't very thin, you can expect your image to be distorted and it can take longer to achieve the image you want or need. The moon has no atmosphere at all. What advantages would you have if you built an observatory on the lunar surface? Active main mirror ventilation - telescopes are not always kept directly at the observing site. This can result in the primary mirror being at a different temperature to that of the environment. A fan, located behind the main mirror holder, blows the cooler air from outside onto the back of the main mirror, thus reducing the cooling time. Any mirror that is less than 6:1 thick is referred to as a thin mirror. Thin mirrors cost slightly less, weigh less, and cool down quicker. But they are much more susceptible to problems with ground in astigmatism and distortion due to support in the telescope unless additional precautions are taken. The resonant tunnelling diode makes use of quantum tunnelling in a very different manner to achieve a similar result. This diode has a resonant voltage for which there is a lot of current that favors a particular voltage, achieved by placing two very thin layers with a high energy conductance band very near each other.
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The telescope is the optical instrument that enlarges the image of the distinct objects using combination of lenses or curved mirrors. The resolving power of a telescope is directly proportional to the diameter of the telescope's objective. Thus, it is given by, Which one of the following describes ...
Telescope mirrors are front silvered and cannot be cleaned like a lens. If you try to do so, you will wipe off or severely scratch the silvery mirror coating, ruining the mirror. Usually the best policy is not to attempt to clean a telescope mirror; the reflective mirror surface should never be touched. The heart of large thin mirror making is in the figuring. Large mirrors call for tremendous amounts of parabolization. Bringing every zone into perfect parabolization is very challenging but doable. I like to parabolize large mirrors in controlled stages. The net result is a steady progression from sphere to parabola with minimal backtracking.