229 – Laser Microphone

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I found a great idea on Leafcutter John’s blog – the Laser Microphone. It’s pretty simple to set up. All you need is a 1/4 inch cable, solar cell, alligator clips, and a laser pointer. I tried out one of his experiments using a Salad Spinner and the results were very interesting. Essentially, the light shining into the solar cell creates an oscillation. The faster the oscillation, the higher the pitch. My salad spinner has a brake feature that lets me stop the spinning pretty quickly, so you’ll hear that too. The photo was created by pointing the laser into my iPhone camera lens.
Check out his blog, which has a video explaining exactly how to make the Laser Microphone. Also, please be careful with the laser and don’t point it in anyone’s eyes!