Anytime we visualize light / sound waves they are 2 dimensional drawing, so how do they actually work in a 3 dimensional space? Are they more like ripples (like a stone thrown into a pond)?
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Sound is waves of compression, so, yes.
Light spreads in rays, so actually light emissions travel in a single line at a time. Emmisive objects happen to cast light in every direction roughly equally
Think of blowing up a balloon. That can be thought to represent an expanding pressure front in three dimensions. The two-dimensional representation would simply be the position of the surface of the balloon on a plane intersecting it.
The waves themselves would consist of multiple such fronts, so it would be a bit like blowing up a balloon that was inside another expanding balloon that was inside another expanding balloon, etc.
I’d say it depends. What are you refering to when you talk about visualizing light/sound waves in 2d? A spectrogram? A diagram of sound traveling across a room?
If it’s the first, that measures certain parameters like frequency (pitch) and intensity (loudness) and presents the information in a graphical way, so that’s the equivalence. If you mean the second, I’d say every “pulse” is like an expanding sphere of light or sound, as long as it’s omnidirectional/unfocused (more or less a lightbulb, a boombox with speakers all around). But you can imagine, if you use a flashlight instead, a laser pointer, or a single speaker, that changes. Now it’s no longer a sphere, but a single cone emerging directionally from the device.
In real life, of course, it wouldn’t be silent outside of the “cone”, but you get me.
Sound wave are longitudinal waves–the wave vibrates in the direction of propagation. Think of a Slinkey sitting on a flat surface like a desk. Hold one side in place and push and pull the other side. This is a longitudinal wave.
Light are transverse waves–the wave vibrates perpendicularly to the direction of propagation. Set up the Slinkey like before, but this time wiggle it from side to side. This is a transverse wave. Light actually has another transverse wave with the same frequency, but the direction of vibration between the two transverse waves are perpendicular–you’d need to oscillate another Slinkey up and down.
Water ripples are transverse waves.
It’s important what is being shown in that 2D example.
A sinusoid graph in not THE wave, it’s just a graph. What’s “waving” is the value it represents. And any point on 3D space can be given those values.
In the case of sound, it’s the local pressure. It’s a bit easier to visualise because it involves actual molecules moving back and forth. So you can imagine a series of balls hitting one another and causing the next one to hit the next etc., in an expanding circle or sphere.
With light it’s difficult to visualize, because the thing that’s “waving” is the local values of the electric and magnetic fields. There’s nothing physical moving or bumping. So the best you can really do is just imagine the spheres representing the peaks and valleys spreading.
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