1. Effects of Media
GAVRT Chapter 4

2. Atmospheric Windows
Atmospheric windows are frequencies at which atmosphere allows em waves to pass
Other frequencies are absorbed by atmosphere
Optical window
Radio window (5 MHz-300 GHz)

3. Absorption and Emission Lines
Single frequencies of EM waves emitted as electron jumps from one energy level to another in atom.
Absorption lines produced when cool gas in line of sight with black body
Emission lines produced when cool gas is not in line of sight with black body
Each element has unique set of lines
Spectral Production picture of page 31 of text

4. Reflection Bouncing of wave off of boundary
Angle of incidence equals angle of reflection
Parabolic reflector of radio telescope
Advantage of Cassegrain design
Law of reflection diagram, page 34

5. Refraction
Bending of waves when they pass from one medium to another (change speed)
Index of refraction
Of vacuum
Other media
Refraction in the atmosphere
Prolonged sunsets
Mirages
Scintillation

6. Interference
Occurs when two waves are at the same space at the same time
Constructive interference results when waves in phase and produces larger waveform
Destructive interference results when waves are out of phase and produces smaller waveform
Constructive and destructive diagram page 37 of text

7. Diffraction Bending of wave without changing its speed
Occurs when wave passes through opening or around edge of object
Slit experiment and explanation
Dark areas where destructive interference occurs
Light areas where constructive interference occurs
Single slit picture, Hewitt interference picture

8. Faraday Rotation
Electric field will feel force from parallel magnetic field.
Force is perpendicular to both fields causing electric field to rotate.
Result is linearly polarized EM wave becoming circularly polarized wave.