What do light wave oscillations look like?
You know what ocean waves look like. Imagine you're in a gin-clear ocean, and there is no surface. Now imagine an ocean wave passes you by. A light wave looks like that. By which I mean it doesn't look like anything.
I know that light waves oscillate, but I don't know how.
They don't really oscillate. You must have been down to the beach and looked at the waves. They move along smoothly. They aren't bouncing up and down.
In textbooks and diagrams they're portrayed as wavy lines traveling through space, but I don't think most light waves oscillate in perfect sine waves like that (unless they're polarized).
Light waves are polarized. They're transverse waves. And like Jac said, they can be plane polarized, circularly polarized, or elliptically polarized. But they're still polarized. Ocean waves are polarized too. And they're portrayed as wavy lines. But again, note that they move smoothly, they don't actually oscillate. If you're in the water you would go up and down and around, like the red test particles. You would oscillate, but the wave itself doesn't.
GNUFDL image by Kraaiennest, see Wikipedia
Note that the wave isn't just some hump at the water surface. It goes down deep. The wave motion gradually diminishes such that at some depth you can't detect it. In this respect the wave takes "many paths" when it goes from A to B.
At first I thought they oscillated in sort of a "spring" shape, like a three-dimensional sine wave, but I later found that that's another kind of polarized light called circular polarization.
Think of that as a combination of linear polarization this ↑ way and this → way.
What I imagine now is the wave going all over the place while retaining the same amplitude and period, like a ball bouncing along in an infinitely long cylinder, but of course I have no idea if that's actually the case.
Get yourself a rubber mat, and shake it. Watch that transverse wave propagate down it. It isn't much like a ball bouncing.
So what do light wave oscillations look like?
Like an ocean wave, in a gin-clear ocean, where there is no surface!