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A refracting telescope (refractor) is a telescope which uses lenses to refract light. This refraction causes parallel light rays to converge at a focal point; while those which were not parallel converge upon a focal plane . This can enable a user to view a distant object as if it were brighter, clearer, and/or larger. These are similar to microscopes. The monocular is a type of refractor. A typical refractor has two lenses, an objective lens and an eyepiece lens. The objective lens has two pieces of glass (with different densitiesFor other meanings of density, see density (disambiguation Density (symbol: rho Greek: rho) is a measure of mass per unit of volume. The higher an object's density, the higher its mass per volume. The average density of an object equals its total mass div), " crownCrown glass is either of two kinds of glass. One type comes from the way window glass was first made. Glass was blown into a crown or hollow globe that is then flattened and cut. It is flattenned by reheating and spinning out the bowl-shaped piece of glas" and " flint glassFlint glass is an optical glass that has relatively high refractive index and low Abbe number. Flint glasses are arbitrarily defined as having an Abbe number of 50 to 55 or less. The currently known flint glasses have refractive indices ranging between 1.". Each side of each piece is ground and polishPolishing is the act of giving something polish, typically through rubbing. Polishing results in a smoother surface with higher shine. Polish can also refer to a compound used in the polishing process. There are two types of polishing: Adding a polish toed, and then the two pieces are glueHistorically, glue only refers to protein colloids prepared from animal tissues, such as hide glue, bone glue, or fish glue. The meaning has been extended to any type of glue-like substances that are used to attach one material to another. See adhesive .d together. The curvatures are designed to cancel chromaticChromatic aberration is caused by the dispersion of the lens material, the variation of its refractive index n with the wavelength of light. Since the focal length f of a lens is dependent on n it follows that different wavelengths of light will be focuse and spherical aberration.
Notable Refracting Telescopes
- Yerkes ObservatoryThe Yerkes Observatory is an astronomy observatory of the University of Chicago, located in Williams Bay, Wisconsin. The observatory was created, in 1897, by George Ellery Hale and financed by Charles T. It represented a shift in the thinking of observato (102cm)
- Lick Observatory (91cm)
- Paris Observatory (83cm + 62cm)
- Nice Observatory (76cm)
Telescopes
