I just read this answer Visualizing Electromagnetic Waves in 3D Space and that's fairly accurate as far as I know.
So, I'm imagining a 3D-matrix of vector sets (details may vary depending on theory) that constitutes the EM-field with right angled E and M vectors.
Now, here's the problem. I know a photon as a lossless straight lined transverse wave of the E and M fields inducing each other. I'm sure you know what I'm talking about. This makes a lot of sense (to me) if all EM-waves are photons and propagate this way. But I'm not so sure about that.
See, my old mental model saw light and radio waves as photons/"particles" that decreased in density as they spread out in random directions when they left the source (or just traveled in parallel as lasers where only diffraction diverged them). But they still had a set energy defined by their wavelength and would individually get absorbed by "compatible" 'particles' (e.g. electrons in atoms in a certain shell etc) which would e.g. excitate an electron. Potentially, the electron gets too much, drops closer to an atom and release a new less energic wave. Some details here may be wrong, but please don't let that take over the whole discussion.
Anyway, then came the n-slits and its equations. I could both in the math and experimentally see how light behave like waves. I know that there's a lot of fuss to this, heisenberg uncertainty, stretching of space at long distances, relativism and you can probably derive between formulas where light is a particle-like and waves. I could be misunderstanding the whole thing. There are a lot of people who knows this better than I do, though this isn't the subject for today either.
But, I have a hard time putting the wave-model you see in slit-experiments in context of EM-vectors in space. It only makes sense when I see it as a lossless transverse wave on a line in 3D-space. If that's how it always work, I can see how they may interfere with each other and perhaps diffract as whole "lines" as edges disturb the wave. From here on I could spend a whole life on uneducated speculations. That's why I'm asking instead.
There's something that just doesn't cut it for me with the string-lined up-down oscillating arrows. Based on what I think I know, I would rather expect light to naturally expand in all directions like sound. But such EM-arrows would not look like in the photons I spoken about. If light interferes with itself as it goes backwards (and moves in 1 direction) I would rather expect it to have a cone-like expansion. Perhaps light waves expands in all direction but the "interference" forward is such that the strongest and only wave top is like a moving ball in one direction? Nope, light is also about phase.
I'm basically asking how the EM-vectors effect the neighboring vectors in 3D-space? It's hard to believe that such a propagation can have 1 direction and not spread out all over the place. I suppose there are different kinds of waves too.. then what do they look like?
Again, all I have under my belt is this kind of 1-dimensional string of vectors that ignores the effect on vectors in the other two directions.