Newtonian telescope 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 Isaac Newton (1642–1727), using a concave primary mirror and a flat diagonal secondary mirror. Newton's first reflecting telescope was completed in 1668 and is the earliest known functional reflecting telescope. The Newtonian telescope's simple design makes it very popular with amateur telescope makers. Newton's idea for a reflecting telescope was not new. Galileo Galilei and Giovanni Francesco Sagredo had discussed using a mirror as the image forming objective soon after the invention of the
Galilean electromagnetism electric field caused by variation of magnetic field according to Faraday's law, or by ohmic currents). If the transit time of the electromagnetic wave passing through the system is much less than a typical time scale of the system, then Maxwell equations can be reduced to one of the galilean limits. For instance, for dielectrical liquids it is quasielectrostatics, and for highly conducting liquids quasimagnetostatics. Electromagnetism followed a reverse path compared to mechanics. In mechanics, the laws were first derived by Isaac Newton in their Galilean form. They had to wait for Einstein and his special relativity theory to take