Winter is a time of year when everything seems to be adorned with festive decorations. From Christmas trees to Santa Claus figurines, the holiday spirit is everywhere. One common design element that often pops up during this season is the snowflake. These delicate and intricate shapes are undeniably beautiful, but their ubiquity can sometimes be a bit overwhelming.
The unique structure of snowflakes is a result of the chemical composition of ice. While it is often said that every snowflake is different, there is actually a distinct mathematical pattern that underlies their formation. Symmetry plays a key role in describing the shapes of snowflakes. Reflection symmetry allows us to draw a line across a shape and see mirror images on either side, while rotational symmetry involves partial rotations that result in the same shape. The order of symmetry indicates how many different positions can be reached before returning to the original shape.
Some shapes exhibit only rotational or reflection symmetry, while others, like regular polygons, possess both. The combination of these symmetries can be described using group theory, a branch of mathematics. The hexagonal structure of a snowflake allows for six lines of reflection and six 60-degree rotations, giving rise to its intricate symmetry. This hexagonal lattice is a result of the chemical bonds in water and ice, leading to the consistent hexagonal shape of most ice structures.
As a mathematician, I appreciate the elegance of snowflake symmetry, even if it is imperceptible to the naked eye. However, I am often irked by decorations that misrepresent snowflakes with incorrect numbers of branches. It is important to remain vigilant and discerning when it comes to seasonal decorations to avoid falling for snow-fakes.
In conclusion, the beauty of snowflakes lies not only in their intricate designs but also in the underlying mathematical principles that govern their formation. This winter, take a moment to admire the subtle symmetry of these frozen marvels, and remember to keep an eye out for authentic representations of nature’s delicate creations.
For more articles on mathematics and science, visit newscientist.com/maker. Katie Steckles, a mathematician, lecturer, and author based in Manchester, UK, shares her insights on mathematical concepts and puzzles. Stay connected with her on Twitter @stecks.

