PHYS 1901 Lecture Notes - Lecture 10: Astronomy Class, Eyepiece, Secondary Mirror
1 Jun 2020
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Document Summary
Telescope is a light bucket: captures photons like rain failing in a bucket. 2 main categories: refractors (lenses, reflectors (mirrors) Speed of light faster in air than in water or glass. Going from 1 medium to the other light rays bend. Light rays from pencil refracted as they leave water (pencil appears bent) Refraction by a prism changes direction of light ray by an amount that depends on angle between prism faces: angle between faces large= deflection large, angle small= deflection small. Light from each small prism bent to a common point focus. Image forms at the focus viewed with small magnifying lens (eyepiece) Magnification calculated by dividing focal length of objective lens by eyepiece lens: magnification= objective lens/eyepiece lens. Magnification changed using eyepiece with different focal length. Reflection of light from flat mirror occurs when light deflected depending on its angle on incidence: angle of incidence = angle of reflection.
