ASTR 111 Chapter Notes - Chapter 5: Radio Wave, Diffraction Grating, Gravitational Field

• School: George Mason University
• Department: Astronomy
• Course: ASTR 111
• Professor: Rebecca Ericson

Document Summary

The energy that light carries is called radiative energy. We measure energy in units of joules. Usually more interested in the rate of transfer rather than the amount of energy light carries. Rate of energy flow is called power. Electromagnetic spectrum (electromagnetic radiation) - complete spectrum of light, including radio waves, infrared light, visible light, ultraviolet light, x rays and gamma rays. White light is what we see - contains all colors of the rainbow. Red, green, blue light - primary colors of vision. Diffraction grating - finely etched surface that can split light into a spectrum. Absorption - process by which matter absorbs radiative energy. Reflection/scattering - process by which matter changes direction of light. Materials that transmit light are said to be transparent. Materials that absorb light are said to be opaque. Newton proved that colors come from light by use of a prism. Wavelength - distance between adjacent peaks of a wave.