OK so I'm familiar with the idea that EM radiation propagates through space in straight lines at a uniform speed, that of light. The idea that light moves in waves, that each wavelength carries a uniform energy and that the wavelength differs yet because the same speed is maintained each burst of radiation will carry differing amounts of energy per unit time. I know that the size of the wavelengths is supported by other evidence like the resolving power of electron microscopes. What I dont understand is why light moves this way. Why a wave? Doesn't that defy the idea that it ought to be moving in a straight line? Can anyone help me to understand this?