Fredagskollokvium: Snow crystals - a letter from the sky

With every winter we are greeted by snow crystals, which can be of great joy, but also indignation. If we look closely at them, we see that everyone is different, but still with many common features. The snowflakes have the same crystal structure, but still produced a wealth of different forms, ranging from needles to large plates with intricate shapes. Common to them all is that they have six-fold symmetry, and by looking more closely at them, we are surprised by how symmetrical they actually are.
This lecture will attempt to explain the similarities among the different snow crystals, but also why they are so different. We will look at how snow crystals are formed and how they grow into their various forms, and why they are so symmetrical.