Microwaves, chocolate chips, and the speed of light.
Okay, chocolate might only be tasty and not pump us full of feel good chemicals, but did you know that you can use chocolate chips and your microwave to measure the speed of light? Yeah no kidding.
I first found this on Curious Cat some time ago and have been meaning to write it up for a while. Okay the instructions are on Superpositioned and it basically works like this. Take a plate of chocolate chips, nuke them for a few seconds and measure the distance between melted spots.
This works because the distance between the edge of the plate and the first melted spot is half of a wavelength, and we know the frequency microwaves (2.4 GHz) and … that’s all you need. Might have to try this over the weekend.
Okay … how to microwaves work? It’s very cool. Microwaves emit their electromagnetic waves at a frequency that makes water molecules vibrate. Vibration creates friction, friction heat, heat cooking. And microwave cooking was another great thing discovered by accident! As I remember a scientist working at MIT on the defense applications of microwaves (microwaves have been know long before they have been harnessed to reheat burritos) set his chocolate bar down next to a microwave emitter that he didn’t think was working (an unshielded microwave emitter! yikes!). Little bit later he reached down and his bar was hot, chocolate goo. Hmm, he thought, I’m onto something here … I wonder if this works for hot dogs and popcorn … (just kidding).
My favourite microwave story comes from my own past. When my parents first got a microwave in the 80s, my mom brought me home a croissant for a snack. She said I could heat in up in the nuker … how long I ask, 10 she says … being new to the whole microwave thing I punched in 10 minutes. I figured out there was a problem when the smoke started billowing out of the machine. Boy, croissants aren’t nearly as appetizing when burned to a lump of carbon.
This goes to show one of the very, very important rules of science … always define your units!
Tags: chocolate, microwave, science experiments
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