Question: how do telescopes work?

Tim Duckenfield answered on 6 Mar 2018:

Great question – the basic idea is to use really polished mirrors to gather and focus light into one spot. These mirrors can be huge and really impressive engineering works, made of exotic metals, coated with pure gold and polished until they are unbelievably smooth. I’d love to see one with my own eyes – but I’d have to be wearing a special clean suit!

We get quite fussy about what kind of light we let into our telescope, since different light can show us different images. For example I use a lot of radio telescopes that use radio light, and ultra-violet light too.