I don’t really understand what it means when radios “tap into” certain frequencies and how they are transmitted.
In: Physics
Radio waves are electromagnetic waves carried by photons, exactly like heat or visible light, but at a much longer wavelength / lower frequency. When those photons move past an antenna, they induce a tiny voltage through it, very loosely similar to how moving a magnet through a coil of wire will generate a voltage.
The problem is, your antenna is equally sensitive to a pretty wide range of frequencies (maybe everything from 88-108 MHz for radio), but the user doesn’t want to listen to 50 radio stations all at once. You need some tool to focus on a specific frequency and ignore all the others. This is called a “bandpass filter,” because a narrow band of frequencies “passes through,” and all other frequencies get thrown away. Tuning your radio means telling that bandpass filter which frequencies it should be paying attention to.
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