Electromagnetic Radiation

Introduction to spectroscopy and polarization:
http://www-wilson.ucsd.edu/education/pchem/spectroscopy/spectroscopy-intro.html

Elementary polarization:
http://www.math-science.sfasu.edu/physics101/Polarization.html

Sonic Doppler Effect:
http://www.explorescience.com/soundwav.htm

Doppler Effect, 2 sources:
http://www.explorescience.com/sndwav2.htm

Doppler Effect Overview:
http://www2.austin.cc.tx.us/astro_heath/Deff.html

Doppler Effect:
http://www.phys.uidaho.edu/~pbickers/Courses/310/Notes/book/node93.html