I’ve seen radio waved depicted in two different ways that seem at odds with one another. the first is something like [this](https://upload.wikimedia.org/wikipedia/commons/thumb/3/3d/Wireless_tower.svg/75px-Wireless_tower.svg.png), with the waves spreading out from a point source in all directions. the second is like [this](https://upload.wikimedia.org/wikipedia/commons/thumb/d/d1/Cross_linear_polarization.gif/330px-Cross_linear_polarization.gif) with the radio wave moving in a “tube” constrained by its own parameters.
since we can’t see them, radio waves remain a bit abstract, but both of these visualizations can’t be correct at the same time… or can they? can someone as to what the real picture would “look” like?
many thanks!
In: 3
One visualizes how they propagate.
You shake the electromagnetic field with your antenna, and this will propagate at the speed of light to everything in sight, bounce around and reach places that are not in visual range. It’s like emitting light. The antenna makes invisible radio “light”.
To be more precise, light is a type of electromagnetic signal. And color is the frequency. Radio waves are from the same family, but are not visible to humans.
So, when your tv receives a tv channel, your tv antenna is seeing the transmitting antenna “changing color” and the tv just transforms that to visible light and put it on screen. (Oversimplified).
The second is what a wave is compared to time.
When you study electromagnetic things, they are invisible and go at speed of light. To make it visible to us, we depict it like a still picture. It’s like if you study the ocean waves, you take a picture of the ocean, show it to people and then show them how the wave is made. You froze it in time to be able to have a still image to explain. Or you make an animation. Everything but showing it at speed of light because that a bit too fast.
I gave it a try. Hope it helped. Sry but that’s a bit difficult to put down in few words.
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