Newtonian telescope secondary mirror. This design reduces the size and cost of the telescope with a shorter overall telescope tube length (with the corrector extending the focal length in a "telephoto" type layout) combined with a less costly spherical mirror. Commercially produced versions of this design have been noted to be optically compromised due to the difficulty of producing a correctly shaped sub-aperture corrector in a telescope targeted at the inexpensive end of the telescope market. Newtonian telescope The Newtonian telescope, also called the Newtonian reflector or just the Newtonian, is a type of reflecting telescope invented by the English scientist Sir
Galilean Galilean Generically, a Galilean is an inhabitant of Galilee. The New Testament notes that the Apostle Peter's accent gave him away as a Galilean (Matthew 26:73 and Mark 14:70). The Galilean dialect referred to in the New Testament was a form of Jewish Aramaic spoken by people in Galilee from the late Second Temple period through the Apostolic Age . Later the term was used to refer to the early Christians by Roman emperors Julian and Marcus Aurelius, among others. After some early expeditions to Galilee to save the Jews there from attack, the Hasmonean rulers conquered Galilee and added