What is NEWTON'S REFLECTOR? What does NEWTON'S REFLECTOR mean? NEWTON'S REFLECTOR meaning

Experience FAST and SECURE Internet browsing with The Audiopedia owned Android browser. INSTALL NOW - http://bit.ly/2Sm5bi0 What is NEWTON'S REFLECTOR? What does NEWTON'S REFLECTOR mean? NEWTON'S REFLECTOR meaning - NEWTON'S REFLECTOR definition - NEWTON'S REFLECTOR explanation. Source: Wikipedia.org article, adapted under http://bit.ly/yjiNZw license. The first reflecting telescope built by Sir Isaac Newton in 1668 is a landmark in the history of telescopes, being the first known successful reflecting telescope. It was the prototype for a design that later came to be called a newtonian telescope. Isaac Newton built his reflecting telescope as a proof for his theory that white light is composed of a spectrum of colours. He had concluded that the lens of any refracting telescope would suffer from the dispersion of light into colours (chromatic aberration). The telescope he constructed used mirrors as the objective which bypass that problem. To create the primary mirror Newton used a custom composition of metal consisting of six parts copper to two parts tin, an early composition of speculum metal. He devised means for shaping and grinding the mirror and may have been the first to use a pitch lap to polish the optical surface. He chose a spherical shape for his mirror instead of a parabola to simplify construction: he had satisfied himself that the chromatic, and not the spherical aberration, formed the chief faults of refracting telescopes. He added to his reflector what is the hallmark of the design of a "Newtonian telescope", a secondary "diagonal" mirror near the primary mirror's focus to reflect the image at 90° angle to an eyepiece mounted on the side of the telescope. This unique addition allowed the image to be viewed with minimal obstruction of the objective mirror. He also made all the tube, mount, and fittings. Newton described his invention as: "The diameter of the sphere to which the Metal was ground concave was about 25 English Inches, and by consequence the length of the Instrument about six Inches and a quarter. The Eye-glass was Plano-convex, and the diameter of the Sphere to which the convex side was ground was about 1/5 of an Inch, or a little less, and by consequence it magnified between 30 and 40 times. By another way of measuring I found it magnified 35 times. The concave Metal bore an Aperture of an Inch and a third part, but the Aperture was limited not by an Opake Circle, covering the limb of the Metal round about, but be an opake Circle, placed between the Eyeglass and the Eye, and perforated in the middle with a little round hole for the Rays to pass through to the Eye. For this Circle being placed here, stopp'd much of the erroneous Light, which other wise would have disturbed the Vision. By comparing it with a pretty good Perspective of four Feet in length, made with a concave Eye-glass, I could read at a greater distance with my own Instrument than with the Glass. Yet Objects appeared much darker in it than in the Glass, and that partly because more Light was lost by Reflexion in the Metal, than by Refraction in the Glass, and partly because my Instrument was overcharged. Had it magnified but 30 or 25 times, it would have made the Object appear more brisk and pleasant" ... "The object-metal was two inches broad, and about one-third part of an inch thick, to keep it from bending. I had two of these metals, and when I had polished them both I tried which was best; and ground the other again, to see if I could make it better, than that which I kept." Newton describes a telescope with an objective concave primary mirror diameter of 2 inches (50 mm) 0.3 of an inch thick, ground to fit a sphere that was 25 inches in diameter giving it a radius of 12.5 inches and a focal length of 6.25 inches (158 mm). The mirror was aperture reduced to an effective aperture of 1.3 inches by placing a disk with a hole in it between the observer's eye and the eyepiece. The telescope had a flat diagonal secondary mirror bouncing the light at a 90° angle to a Plano-convex eyepiece with a probable focal length of 4.5mm yielding his observed 35 times magnification. Newton said the telescope was 6.25 inches long; this matches the length of the instrument pictured in his monograph "Opticks". It appears that the second telescope, which was presented to the Royal Society has a longer focal length as it is significantly longer than the first one shown in his illustration and described in "Opticks". Newton completed his first reflecting telescope in late 1668 and first wrote about it in a February 23, 1669 letter to Henry Oldenburg (Secretary of the Royal Society).".....