Place those lenses in a tube and voilà ... Standing on shoulders Both types of telescopes—Galileo's refractor and Newton's reflector—underwent improvements in the coming centuries.

Celestron AstroMaster 90AZ now $159. This is a good-quality beginner telescope. It features a 90mm objective lens with quality glass optics and a range of accessories which includes a smartphone ...

Shaping a lens allowed for fine control over the ... However, there are workarounds, such as the straight-outta-sci-fi Wolter telescope. This type of telescope uses ring-shaped 'glancing' mirrors ...