Monday’s hands-on science program, “The Science Behind Recording Music,” challenged tweens to come up with several iterations of a gramophone that could play the sound stored on a vinyl record with only their hands to power it. First tweens learned about the history of sound recording and its great inventors, then we started spinning records of our own. We made a gramophone out of a tin can, aluminum foil, and a pin, and lowered the pointy end of the pin onto the record while we spun it to see if we could hear sound. The pin should pick up the vibrations from the groove of the record and transfer those vibrations to a diaphragm (the tinfoil) and then amplify them (with the cylinder or funnel). We tried latex instead of tinfoil, and funnels instead of cans, and finally a simple paper cone (which was the lightest version and therefore the most effective!). Kids had to write down observations and notes about how each machine worked and rate its effectiveness in loudness and clarity.
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