A snowflake is known as a symbol of winter because of its uniqueness. But have you ever wondered how a snowflake becomes so different and why “no two snowflakes look the same?” Well, a snowflake first appears high up in the clouds where the temperature is below freezing. There, tiny particles coming from dust, pollen, sea salt, etc act as a nuclei which allows water vapor to attach and freeze. As more and more water vapor attaches, the more hexagonal it gets, until it freezes and becomes the iconic hexagonal shape.
But that’s not the end for snowflakes which still need to get shaped into individual designs. For the designs to take shape, temperature and humidity play the most important role of all. As temperature fluctuates, so does the pattern that will form. For example, colder temperatures will cause more thin and long shapes to take form while warmer conditions will cause more branching. Humidity plays a role in how much water vapor is available. When there is high humidity, the snowflake is able to grow more complex designs while low humidity will cause more simple shapes. So, as a snowflake falls to the ground, it will pass through many levels of varying temperatures and humidity, causing its design to constantly alter and evolve, making it impossible for any other snowflake to replicate exactly.
There is also chemistry behind snowflake creation. Snowflakes are made up of water molecules arranged in a crystal lattice held together by hydrogen bonds. The angle that the hydrogen bonds form causes a six sided symmetry which is present in all snowflakes. However, tiny variants in molecular attachment as well as impurities in the air and fluctuations in environmental conditions will affect how the bond forms. There is no limit to what can change a bonding for even the most microscopic differences in chemical composition or air pressure can change the rate and growth of a snowflake.
Moreover, different factors can further increase snowflake individuality. Air currents cause snowflakes to change course and rotate, exposing its many different sides to water vapor. In the air, there are also many other snowflakes that are being formed at the same time, so collisions often break apart snowflakes and lead to a regrowth. Factors like gravity and wind speed all influence how long a snowflake is up in the air before reaching ground. Since no two snowflakes experience the same exact route to the ground, no two snowflakes look the same.
In total, these physical, chemical, and environmental factors all ensure that every snowflake is different and that no two are the same. Scientists use snowflakes to better understand cloud changes, climate patterns, and precipitation. Snowflake research also inspires art and photography, showing how natural processes combine science and beauty in ways that continue to interest people around the world today across many different spaces.
