What is Radial Symmetry
Snowflakes provide wonderful examples of symmetry. It is useful to engage students in examining the various forms of symmetry. There are basically two types of symmetry: • Rotational symmetry (also known as Radial symmetry) • Reflection symmetry (also known as Bilateral, or Mirror symmetry) What is the difference between these two types of symmetry? • Rotational symmetry – You can cut the image in half in more than one direction, and the two halves will appear as mirror images of each other. The object has more than one line of symmetry. Examples: A triangle can be cut along three different axes. A circle can be cut along an infinite number of axes. The two photos below are examples of rotational symmetry. How many lines of symmetry are possible in each?(http://www.mathematicshed.com/uploads/1/2/5/7/12572836/snowflakes.pdf)
Why do Snowflakes have Radial Symmetry
Snowflakes are symmetrical because they reflect the internal order of the water molecules as they arrange themselves in the solid state (the process of crystallization). Water molecules in the solid state, such as in ice and snow, form weak bonds (called hydrogen bonds) to one another. These ordered arrangements result in the basic symmetrical, hexagonal shape of the snowflake. In reality, there are many different types of snowflakes (as in the clich¿ that 'no two snowflakes are alike'); this differentiation occurs because each snowflake is a separate crystal that is subject to the specific atmospheric conditions, notably temperature and humidity, under which it is formed.
The second question has to do with the way in which snowflakes are formed. The growth of snowflakes (or of any substance changing from a liquid to a solid state) is known as crystallization. During this process, the molecules (in this case, water molecules) align themselves to maximize attractive forces and minimize repulsive ones. As a result, the water molecules arrange themselves in predetermined spaces and in a specific arrangement. This process is much like tiling a floor in accordance with a specific pattern: once the pattern is chosen and the first tiles are placed, then all the other tiles must go in predetermined spaces in order to maintain the pattern of symmetry. Water molecules simply arrange themselves to fit the spaces and maintain symmetry; in this way, the different arms of the snowflake are formed.(https://www.scientificamerican.com/article/why-are-snowflakes-symmet/)