I know that it’s electrowaves but how does it become sound again ? How are there several channels ?
In: Technology
OK, so let’s shift this up a bit in the spectrum. Imagine trying to send information using a torch at night. I can point a torch at someone, and turn it of and off (or put my hand in front of it, shift between aiming directly at the receiver and the sky, etc) and thus send a message via some agreed code (like morse code, or binary or “one if by land, two if by sea”, etc). The changes in the amplitude(“strength”) of the incoming signal is how we encode, the message. This is AM radio.
We can make it any colour we want, and just tell the person watching to look out for, say, red lights, or green lights. Maybe we give them coloured glasses so they can only see red lights(ie we add a filter). This way, we can have multiple signals being sent to multiple recipients at the same time without confusion
Another thing we could do it have a constant light, but if shifts between red and green to to encode the message. Now. Instead if changing the amplitude. We are changing the frequency of the signal for encoding. We might need to change our filter set up, but the basic principle of the recipients knowing to just look at the pre arranged pair of frequencies/colours and ignoring other ones stays the same.
Using this method of encoding information onto the light, we can send the information about the sounds over the link we have created, same as, say, electrical pulses down a wire
Does that make sense?
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