Chapter 4: Astronomical Telescopes and InstrumentsSmooth surface: mirror-like reflectionin a particular directionRough surface: scatter = reflection in a variety of directions~movie screen: designed to scatter light strongly in all directions; how we see planets/moon Transmission: light (maybe partially) passing through a medium~the light often “bent” on the process – this is called refraction~the sun appears distorted at sunset because of refraction in Earth’s atmosphereAbsoption: light may also be absorbed~an object that absorbs all light is opaque~an object that only partially absorbs light is translucent~often different for different colours!Interaction of light with matter determines the appearance of everything we see (ie. If it’s red it’sbecause it reflects red light)Photons: a particle of light, whose energy depends on frequency
