Does visible light travel in beams or waves?

Question

I was wondering if it is electromagnetic radiation then it should travel through space in the form of waves, but when shone through a slit in a piece of thick black paper and onto un-exposed photography paper it leaves one straight line, shouldn't I see ripples if it bounces/ moves in waves off the point of contact ? shouldn't I see this if it's a wave??

http://abyss.uoregon.edu/~js/images/interference.gif

Answer 1

 by sukin ma lun