Astronomy 1021 Lecture 7: Astronomy- Nov 3rd

• School: Western University
• Department: Astronomy
• Course: Astronomy 1021
• Professor: Sarah Gallagher

Document Summary

All matter emits and absorbs light, but at different wavelengths depending on composition and temperature. Reflected/scattering: you have light coming in and light going out (mirror like reflection, if surface is rough= scattering, you don"t preserve the image like you would on a flat surface. Absorption: absorbed, an object that absorbs light is opaque, an object that can partially absorb light is translucent. Transmission: light passing through a medium- transmission, light often bent in the process- refraction, light travels more slowly through a liquid then air. The sun appears distorted at sunset because of refraction in earths atmosphere. Interactions of light with matter determine the appearance of everything we see. Light can act either like a wave or like a particle. Light can act like particles called photons whose energy depends on frequency. Photons interfere like waves, but have momentum like particle. A wave is a pattern of motion that can carry energy.