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Can you fi nd the symmetry in these snowfl akes?


Snowflakes Up Close T ere’s another place to look for rotational symmetry. Bundle up and go out in the snow. Whirling and twirling snowflakes blow in every direction. It’s a blizzard. T ere’s no order within this chaos. Or is there? A snowflake lands on you. Quick, before


it melts, take a look. You’ll see one of most beautiful examples of symmetry in nature. You may need a microscope. It’s hard to see a snowflake’s tiny patterns with your naked eye. A snowflake forms when water vapor


freezes. It turns into an ice crystal. It forms a hexagon, with six sides and six points. Six matching branches grow from each point. T e branches have the same ridges and grooves. It’s actually hard to find a perfectly


symmetrical snowflake. Most start out that way. T en, as they fall, they slam into each other. T at can damage these fragile crystals. Branches break. Snowflakes melt. Just like that, their symmetry vanishes.


Seeing Symmetry From deep in the sea to high in the clouds, symmetry is all around you. Now it’s your turn to find it. Look for a caterpillar with bilateral


symmetry. Find a flower with rotational symmetry. Once you start looking, you’ll see nature’s symmetry all around you.


WORDWISE


asymmetrical: when an object lacks symmetry, or a balance of matching parts


bilateral symmetry: when a line can divide an object into matching halves


rotational symmetry: when matching parts are arranged around a central point


symmetry: when matching parts in an object are evenly arranged along a dividing line or around a central point


NOVEMBER-DECEMBER 2012 9


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