I really can’t grasp the concept of waves. I can imagine it a bit for sound waves: a speaker has a surface that pushes air, and the moving air eventually pushes the membrane in our ears.
But I’m confused about wifi etc. What exactly is the thing that physically travels? Is it air or something else? Does it physically move in a wavy pattern?
Edit: thanks for all the answers! But damn I’m overwhelmed. It’s gonna take me days to read and fully understand the answers. But thanks!
In: 87
To break this down as ELI5 as I can:
Radio only consists as a wave in the sense that something about is cyclical, meaning it repeats itself. In this case, it’s the voltage that makes it a wave, because the voltage changes back and forth. It needs to do that in order to generate the “wave” in the first place.
Think of it like this. You have a bowl of water, and you stick your finger in the water, but otherwise don’t move it. What happends? The water level raises up a bit, but is otherwise unchanged. Now wiggle your finger back and forth. Doing this creates waves in the water, and the faster you wiggle your finger the faster the waves seem to get.
Radio works much the same way. Stick up an antenna and put a current at a constant voltage through it, and all you’ll do is contribute to the overall ambient electromagnetic energy in the area (we call this “raising the noise floor.”) To actually get a signal through, you have to “wiggle” the voltage back and forth to “create the waves.” The rate at which you “wiggle” the voltage is the frequency of the signal. Your local radio FM station on 101.5? It’s “wiggling” the voltage 101,500,000 times per second. And when you draw that voltage change on a graph, it looks like a wave (it’s mathematically represented as a sine wave).
Hope this makes sense.
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