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You might be aware that microwave ovens have hot and cold spots (thats why many of them have little turntables that spin around while your food heats), but have you ever wondered what they look like? Luckily, some folks from Robots & Dinosaurs were thinking about it as well, and decided to measure the effects once and for all.

Detecting waves in space can be pretty complicated, but luckily they happened to have a thermal camera on hand to use. To image the hot spots, they placed a wet piece of paper in the microwave, and trained the camera on it. When they turned on the oven, the hot and cool spots (caused by standing waves in the heating chamber) heated different portions of the paper differently, which the thermal camera could easily pick up. Cool stuff!

Of course, you can’t really do much with this knowledge- it would be neat to know exactly where to place food to heat it the fastest, however just the act of putting different things in the chamber will completely change where the spots are. Still, it’s neat to see that the phenomenon does exist!


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Comments

  1. Josh Kopel says:

    If you don’t have a fancy pants thermal imaging camera, you can also stick a piece of damp thermal fax paper in there. The hot spots make black areas on the paper.

    Of course these days thermal fax paper is almost as hard to get a hold of as a thermal camera.

    1. Matt Mets says:

      Oh, that sounds great! If you can’t find thermal fax paper, someone suggested that a plate of marshmallows will work as well :-)

    2. R3becca says:

      Great idea Josh.

      Also, I created an animation from our image sequence:

      http://imgur.com/NKQuH.gif

  2. Kathryn Small (Robots & Dinosaurs) says:

    It was great to finally use the microwave for an experiment where it *probably wouldn’t* blow up. This is probably because we only have one microwave. If we had two, we’d *have* to pull the second one apart :D