Astronomy 1021 Lecture Notes - Lecture 7: Refraction

• School: Western University
• Department: Astronomy
• Course: Astronomy 1021
• Professor: Robert Cockcroft

Document Summary

All matter emits and absorbs light, but at different wavelengths depending on composition and temperature. Smooth surface: mirror like re ection in one particular direction. Rough surface: scattering=re ection in variety of different directions. Blue light is more easily scattered than red. Light takes a longer path through the atmosphere at sunset. More blue light gets scattered out at sunset. An object that absorbs all light is opaque, an object that only partially absorbs is translucent. Frequency: number of times per second that wave vibrates up and down. Light interacts with charged particles through these electric and magnetic elds. Do not need a medium to propagate through (light can travel through the vacuum of space) Electromagnetic waves travel at 3 x 10^8 m/s. Two photons of the same blue color also have the same wavelength, the same frequency and the same energy: they are identical. Molecules are made up of even smaller entities called atoms.