IR_Remotes

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Introduction:
When we use the EM Spectrum for communication, we set up transmitters and receivers. In this activity, we will use Infrared Remotes as transmitters, and the Macbook camera as a receiver.

Activity:

 * Open Photobooth, choose the Effect called Thermal Camera, and switch to Record Movie (command-T).
 * Aim the remote control at the Macbook camera and press-and-hold a variety of keys (you will need two distinct patterns to study).
 * Drag the video clip to your desktop and double click it. (The video should open in QuickTime Player.)
 * Study the patterns in the Infrared beam and see if you can detect a pattern in the signal that would transmit a different code for different keys.

Conclusion:
Infrared signals are part of the EM spectrum that are not visible with the naked eye. However, special receivers can detect the code and display the transmitted signal in a way that we can see.

Practice:
The Infrared part of the spectrum is a lower frequency than the light that is visible to our eyes. You can practice your understanding of the range of EM radiation with the following Quia quiz.