The classic picture of light is as an electromagnetic wave. In textbooks you get the nice pictures of eletric and magnetic field vectors bound together at right angles, oscillating on into the distance. However, this is a very one dimensional picture. The electric and magnetic fields would only be felt along a line. What happens if you're standing 1 cm away from the axis of propagation? How about 1 nm? Is there a more complex 3-D description of light as a wave? Even if there is a fast decay in field intensity away from the axis and it can be approximated as 1-D, the familiar vector description seems inadequate to me. I'm guessing some responses may invoke plane waves, but I am fine with those. It's really only the 1-D description that concerns me. Perhaps, because it's a classical description of a single photon, quantum mechanics must instead be used here, and the 1-D classical description really isn't valid for a single photon? Any other ideas?