Photo Cred

1.http://academic.greensboroday.org/~regesterj/potl/Waves/DiffractionInterference/Diffraction.html
2.http://www.exo.net/~pauld/lectures/patternscostarica/patternsnature2004.htm
2.http://twilit.wordpress.com/2008/03/15/bubbles-and-interference/
3.http://www.physicsclassroom.com/class/waves/Lesson-3/The-Doppler-Effect
4.http://www.blogodisea.com/2011/derrumbe-puente-tacoma-narrows-1940/ciencia/