Why are light waves/X-rays/gamma rays/etc. in the form of sine waves, rather than, say, a zig zag wave, or even a straight line? I recently watched this youtube video explaining how to visualize ten dimensions: http://www.youtube.com/watch?v=JkxieS-6WuA&feature=related And wondered if photons behave as a sine wave because they were going in circles in some other dimension (or something) and that (somehow)( I'm just in precalculus II I can't explain my guess any further) is the reason for why the wave is a sine wave. I just made the connection, but I'm 50% sure circles have nothing to do with the sine wave behavior of light. I'm just curious. Thanks for your insight. edit: actually it was carl sagan's explanation of the 4th dimension that got me thinking: http://www.youtube.com/watch?v=Y9KT4M7kiSw&feature=fvw edit: thank you for your answer.