What is Gregorian telescope?
A '''Gregorian telescope''' was the first [[telescope]] to be designed that uses [[mirrors]] instead of [[lens]]es. It was invented by the English [[astronomer]] John Gregory. Even though it was designed in 1663, it wasn't the first reflecting telescope to be built. Newton's telescope, a different design, was built in 1668. The Gregorian telescope was first built in 1673 by [[Robert Hooke]]. The telescope uses two curved mirrors. The large primary gathers light, and the small secondary reflects the light out the back of the primary mirror. Both mirrors are concave (bowl-shaped). It is very similar to the Cassegrain telescope, which uses a large concave primary mirror and a small convex secondary mirror. {{science-stub}} [[Category:Telescopes]]