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
Derivations of the Lorentz transformations transformation matrices are consistent with group postulates: If then we get the Galilean-Newtonian kinematics with the Galilean transformation, where time is absolute, , and the relative velocity of two inertial frames is not limited. If , then we set formula_117 which becomes the invariant speed, the speed of light in vacuum. This yields and thus we get special relativity with Lorentz transformation where the speed of light is a finite universal constant determining the highest possible relative velocity between inertial frames. If the Galilean transformation is a good approximation to the Lorentz transformation. Only experiment can answer the question which