ASTR 3 Chapter 2-1: Astronomy 3 Textbook 2.1 Notes
Document Summary
Astronomers use laws of physics to interpret light or electromagnetic radiation emittd by objects. Radiation: way in which energy is transmitted through space without need for any physical connection. Electromagnetic: energy in beam of light is carried in form of rapidly changing electric and magnetic fields. Visible light: light human eye can see. Also invisible electromagnetic radiation like radio, infrared, ultraviolet, x-ray, gamma, etc. All electronmagnetic radiation travel through space in form of waves, which is way in which energy is transferred from place to place. Energy carried by disturbance that occurs in distinctive repeating pattern. At any point in the wave, the point moves up and down according to the wave, does not move with the wave. Wave is just the pattern of up-down motion, this pattern is transmitted from one point to the next. Wave period: number of seconds needed for wave to repeat itself. Wavelength is number of meters needed for wave to repeat itself.
