Freezing fun

                                              “Creativity is intelligence having fun.” - Albert Einstein
 
Color an icicle: First rub an icicle with salt (coarse salt like kosher salt works best) to give it a rough and interesting texture. Then add drops of food coloring or watery paint to the icicle to get a wonderful effect. Let the colors run into each other – or keep them separate – or paint a picture. If you don’t have an icicle, color ice on a puddle or a sidewalk, but be sure it’s a surface that you don’t mind dyeing.
 
Make an ice balloon: Put a few drops of food coloring into a collapsed balloon. Then fill it with water and tie the end. Put the balloon outside on a frigid day and wait for it to freeze. It may take all day. Bring the ice balloon inside and use scissors to cut the knot and slit the balloon open. Peel the original balloon away.
 
Experiment with the ice balloon. Put it in water to watch how it melts. How much of the ice balloon is above water and how much is below? (This is true of icebergs too.) Add salt to the surface that floats above water. What happens?  What else can you do with the ice balloon? Use a fork, a magnifying glass, or a flashlight to experiment further. What could you do with it outside? What could you make with ice balloons? 
 
Freezing Fun for older children
 
Lower the albedo: The amount of sunlight reflected by a surface is known as its albedo. Ice and snow are bright surfaces with high albedo, reflecting about 70% of the sunlight falling on them. So ice on water, or snow on land, keeps the Earth cooler than it would otherwise be. A rise in the temperature of Earth can trigger a feedback. First there is melting of some snow and ice, leading to the exposure of low‑albedo land or water surfaces. That increases the amount of sunlight absorbed by the Earth’s surface and leads to a further rise in temperature as a result. This is known as the ice‑albedo feedback.
 
On a cold, sunny day, fill two square cake pans with snow. Cover one with black paper. Place both pans in direct sunlight. Ask children to guess which pan of snow will reflect the most sunlight and which will absorb the most sunlight – in other words, which pan of snow has the highest albedo. Ask them to predict which pan of snow will melt first. If the outside temperature is too cold for melting to occur, you can do this experiment inside in front of a window that receives direct sunlight.
 
Consider the future of our planet: Scientists have made direct measurements of atmospheric carbon dioxide levels for over 50 years. In addition to this, scientists investigate earlier CO2 levels by collecting samples of air trapped in ice cores extracted from the Antarctic ice sheet and from suitable glaciers around the world. The ice core data show that the concentration of CO2 in the atmosphere is higher today than it’s been for at least 800,000 years, and the rate of increase has been 100 times faster than any previous change in the ice core record. (Statistics posted by the Science Museum in London.)
 
Discuss the effect of increased CO2 (carbon dioxcide) in the atmosphere – the greenhouse effect that contributes to climate change. Ask children to list ways that individuals, institutions, governments, and corporations can reduce the amount of carbon that we discharge into our atmosphere.
 
Make an icicle: On a freezing day, give older children a large bottle of water and a turkey baster. Let them devise a method for making an icicle – or enlarging an existing one. Can they make an icicle longer, fatter, or oddly shaped?
 
Make an ice sculpture: Have children research online to see photos of fantastic ice sculptures. Don’t overlook ice hotels! How are ice sculptures made? Have children make an ice sculpture – or a snow sculpture.

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