@footmunch: Was busy for a second during the live stream, missed the cat but knew there was one. Open this page, ctrl-f "cat" and boom what a great country.
@vinny wisely limited the scope of his wave talk. I am decidedly unwise, so let's science, @danryckert
If you were to row a boat out into a lake and throw a rock twenty feet away into the water, you'd see ripples (aka waves) in the water emanating from the disruption (the place the rock hit the water). On the boat, you wouldn't feel a big solid burst of water knocking you about; you'd instead get rocked a bit as each ripple hit you. The number of ripples that hit your boat every second is called the wave's frequency, so you get hit by 5 ripples every second then the frequency of the water wave would be "5 per second." The height of each ripple is called the wave's amplitude; throw a bigger rock, you should see a bigger amplitude. Fun fact, the "wave" isn't the water, it's an abstract pattern of displacement that happens to be moving THROUGH water (we call water the "medium" for this wave). Anyways.
Assuming that everything works as intended, if you clap your hands, you hear something. What's happening here is that you are displacing air (rock hits the lake surface), sending puffs of it all over the place (ripples in the lake), including toward your ears (the rowboat). If you could SEE the air (and could see very tiny details), you'd see that it's not moving in one big chunk, rather in very quick fits and spurts, pockets of MORE AIR followed by pockets of LESS AIR, just like the water ripples (thus, what you might call "sound waves" are waves in air pressure). The air hits your eardrum, which wobbles back and forth a bit based on the frequency and amplitude of this incoming air disturbance, and your brain interprets the wobbling as sound. The frequency determines the pitch, and the amplitude determines the volume. To put it poorly, your eardrum is getting hit all the time by tiny little basketballs of air, and your hearing apparatus interprets the size of those basketballs as volume and the rate at which they are hitting you as pitch.
Radio waves are no different except for the one very important way in which they are: radio wave have no "medium." In the lake, the wave was displacing water Clapping your hands created a wave that was displacing air. Way back in the day, it was suggested that electromagnetic (EM) waves (radio, wifi, light, you name it) displaced an invisible material called "ether." Modern thinking suggests that this is not the case. Instead, EM waves represent ups and downs in "electric potential." Electric potential deserves its own long post, so let's just say that it's the driving force behind electrical current. More importantly, it can be pretty easily measured with the right equipment, say, a radio receiver. The radio station has an oscillator that generates EM waves. A station you hear at 89.9 FM is making EM waves (NOT air or "sound" waves) that "hit your boat" 89.9 million times each second. Between those big peaks they stuff fluctuations that your radio receiver can unpack into the sound of your favorite drive-time DJ. It sends that signal to the speaker, which displaces air, which allows you to hear the DJ. It's as easy as...
Station --> EM wave --> receiver --> speaker --> air pressure wave --> your ear
Waves are everywhere. They explain how we see, how we hear, even how we drive on a congested freeway. Holla atcha boy if you have further cool questions!
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