Yes , this Pilates instructor is , but just because someone is a pilates instructor doesn ' t mean they Don ' t know anything about life <| sep |> You are right , most wireless communications are based on the manipulation of electromagnetic waves of different frequencies . This is a very powerful and intuitive piece of knowledge , because it means that you know a lot about the properties of radio waves for example because you intuitively know some properties of visible light it can be reflected by a suitable surface , suffers refractions under the proper conditions , can ' t go through opaque bodies , etc . Of course , this opens some further questions to see the light emitted by a potent flashlight from very far away , you generally need to have direct vision of it . Why is it then that you can sometimes turn on your radio and hear a station which is emitting from miles and miles away ? And why can you sometimes receive inside a room surrounded by four seemingly opaque walls ? Think about it ! Generally speaking , when you want to use a part of the electromagnetic spectrum to transmit something , you need to have a component or a circuit which can generate the waves you need so you can transmit and some other component or circuit which can react only to the generated waves so you can receive only the stuff you are interested in . In your experiments you have used a LED , a light emitting diode , to generate the light waves , and a photodiode to receive . Perfect ! If you want to use radio waves instead , however , there ' s no such a thing as a radio emitting diode instead an antenna is used , which is nothing more than a piece of metal which radiates waves of a specific frequency when you feed it some voltage . Of course , another antenna will be at the receiving end . But the concept is the same as with the LED ' s . I have always found this radio stuff kind of magical , even though there ' s nothing magic about the physics . But a man is talking miles away from here and I can hear him by just turning a dial ? Without any cables ? Magic !