Sun 4 Jan 2009
Things to do in a microwave #1: Find your microwave hot spots
Posted by sciencegeekgirl under Weird Science Tricks[6] Comments
I’ve been wanting to do a series of posts on Fun Things To Do with a Microwave, and I’m just going to get off my butt and DO it! For some of these to work well, you need to know where your microwave hot spots are.
What do we mean by hot spots? Microwaves are just one form of radiation — like x-rays or visible light — of a particular frequency. The reason they chose microwave frequencies for ovens is that this frequency is more readily absorbed by water. The microwaves are pretty long (about the size of a grape, as you’ll see in the next post), so you get a regular pattern of peaks and troughs (or hot and cold) as the waves add and subtract (it’s a checkerboard, like two-slit interference). You may have noticed that food cooks slower at the center of a microwave and faster at certain other places (that’s why those rotating plates are handy).
Method 1: THE WATER METHOD (From RealSimple)
You can find the hottest parts of your microwave by placing custard cups or small bowls filled with water all around the oven. Heat for 1 to 2 minutes, checking every 30 seconds. The ones that boil first are in the hot spots.
Method 2: FAX PAPER gives a more permanent map (from Barnesos.com)
Take a damp paper towel and place it on top of 5-10 other paper towels in the bottom of your microwave. On top of it, place a sheet of themally sensitive fax paper, the kind that old crappy fax machines use. Credit card recipts also work, but they’d be harder to tile the bottom of your microwave with. The extra towels at the bottom provide some insulation. Turn the microwave on for a while. The first areas on the paper to turn dark are the hot spots.
Method 3: MARSHMALLOWS (or chocolate chips)
Or a tasty way is to place marshmallows all over the bottom of the oven (might want to put a paper towel down first). Greater pixel resolution with the tiny marshmallows (more Marshmallows Per Inch!)
Here’s a kid-friendly explanation of microwaves (as well as a simulation of the marshmallow method) and a kid-friendly explanation of hot spots.
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6 Responses to “Things to do in a microwave #1: Find your microwave hot spots”
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Vaelek
Posted: Jan 4th, 2009 at 9:42 pm1Reply to this comment.Arcing a grape still has to be one of my favorites. The materials required don’t get much cheaper either
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sciencegeekgirl
Posted: Jan 4th, 2009 at 9:54 pm2Reply to this comment.Don’t spoil the fun! That’s my next post.
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chase
Posted: Jan 5th, 2009 at 10:58 am3Reply to this comment.Okay, this was way cool. I had no idea how the “magic heat box” worked. I just knew not to put a metal plate or an egg in it. “Hot spots,” huh, so that explains why my mac n. cheese has to be stirred before it’s all equal temp. Say, is it true microwaves cook “from the inside out” or is that just eighth grade gibberish I picked up somewhere?
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Tom
Posted: Jan 7th, 2009 at 10:00 am4Reply to this comment.I’ve seen marshmallows and chocolate chips used for this investigation, too.
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sciencegeekgirl
Posted: Jan 7th, 2009 at 10:26 am5Reply to this comment.Chocolate chips, that’s a good idea! (I did mention the marshmallows in the post).
A friend and I were discussing, too, you can choose the pixel resolution of your microwave map by choosing the large or small size marshamllows! “MPI” (marshmallows per inch)!
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pingback:
Posted: Oct 31st, 2009 at 1:32 pm6sciencegeekgirl » Animal rights and microwave hot spotsReply to this comment.[...] blogged a while back about mapping out the hot spots in your microwave with fax paper, or marshmallows or chocolate chips. (Your food is not heated at the [...]