This visit was arranged by Ellen Lettvin, APL Assistant Director for Education and Development. OK, the thing is, her son is in this class! Personal connections usually are key…
Over the past year I’ve developed a kid’s sea ice “show” which includes pictures of sea ice, native peoples, and animals. I also show them instrumentation (CTD’s, XCP’s) and cold weather gear (big coats and boots). But the real star of the show is the liquid nitrogen, which I use to freeze various things like flowers, bananas, paper, and of course, water, both fresh and salty. For more details, see my visit to Lowell Elementary School in November, 2003.
Here are some highlights of the Laurelhurst visit: |
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| Pouring liquid nitrogen into a container. We discussed that air is mostly nitrogen. “What do you think it takes to make it into a liquid?” |
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| Freezing a flower. I try to get one with lots of petals. “Hey, it looks pretty much like it did BEFORE I put it into the liquid nitrogen! How do you think it’s different?!” Then I crash it into a zillion pieces. |
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| Freezing a banana. I wasn’t going to do this, but they pleaded with me! |
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| An air balloon is released from the liquid nitrogen and puffs up as it warms. Wow! |
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| OK, time to do some arctic science. We (Mike and Wendy) filled small balloons, some with fresh water and others with salty water (with student assistance, of course). Then we made ice in “faster than real time!” Here I am showing a sample of each. “How will you figure out which is which?” |
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| We use food coloring to distinguish fresh from salty ice. The salty ice sucks the dye into its brine channels! |
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