Adabot: Ladyada …
Ladyada: What’s up Adabot?
Adabot: I was wondering … why does each radio station have its own number?
Ladyada: Oh those numbers are the frequency of each station’s broadcast.
Adabot: What is this “frequency” you speak of?
Ladyada: Well … Frequency is the measurement of how often something happens.
Adabot: huh …
Ladyada: Hmm - It might be easier to tell you about frequency … with the help of my oscilloscope here.
Ladyada: Just need to find my oscilloscope probes … I’ll be right back - wait here, ok?
Oscilloscope: *psst* - hey over here!
Adabot: Who said that?!
Oscilloscope: Me - the talking screen over here.
Adabot: Oh hello, talking screen!
Oscilloscope: I’m not just a screen - I’m an oscilloscope! - and I could tell you quite a bit about frequency.
Adabot: Oh really? Like what?
Oscilloscope: Well - like Ladyada was saying - frequency is how often something happens over time. And we measure frequency in units called “Hertz”
Adabot: (troubled) Oh - does frequency hurt?
Oscilloscope: No, not at all! That’s a totally different word :)
Adabot: Oh good!
Oscilloscope: Hertz is spelled H-E-R-T-Z. It tells us how many times something is happening per second.
Oscilloscope: Watch this -
Oscilloscope: Right now my screen is flashing once per second. So we can say it is flashing at a *frequency* of one *hertz*.
Oscilloscope: Now my screen is flashing a bit faster - 3 times per second which is a frequency of three hertz.
Adabot: Got it - Hertz means - “how many times per second”!
Adabot: So … how is frequency important for radio stations?
Oscilloscope: Good question!
Oscilloscope: You see - a radio station uses a large antenna to send out waves of electromagnetic energy. We call these “radio waves”.
Oscilloscope: Each station broadcasts at its own special frequency, so they don’t get confused with another station.
Oscilloscope: So when you tune your radio to 93.9, for example … you’re telling it to only receive radio waves which have a frequency of 93.9 million Hertz. Your radio then converts those radio waves into sound, so you can hear the station which broadcasts at that particular frequency.
Adabot: Wow - all that happens so I can hear music?
Oscilloscope: Yes it does!
Oscilloscope: Indeed - and Frequency is also very important for audio as well.
Adabot: Audio - like the sound waves that come from the speaker?
Oscilloscope: You see - a sound wave is a vibration moving through the air. And the frequency of a sound wave determines the pitch of that sound.
Oscilloscope: A slow moving or *low frequency* wave sounds low-pitched and bassy.
Oscilloscope: And a fast moving, *high frequency* wave has a much higher pitch.
Adabot: So slow waves sound low and fast waves sound high?
Oscilloscope: That’s right!
Ladyada: Ok Adabot - I think this will help clear up what frequency is all about.
Adabot: No need Ladyada - it all makes sense now!
Oscilloscope: Oop - I think someone’s coming - gotta go!
Take care Adabot - stay curious!
Adabot: Oh - thanks for your help oscilloscope, I will!
Adabot: Frequency is how often something happens over time. Knowing about frequency helps us tune into radio waves, or create sound waves at different pitches.
Ladyada: Wow - you do know about frequency. Where’d you learn all of that?
Adabot: My friend the oscilloscope here just told me *all* about it.
Adabot: Hey, oscilloscope - you ok in there?