A snow crystal forms in clouds when water vapor encounters small specks of dust or pollen. This causes its small hexagonal center to form. Their ends stick out and are rough and this attracts water molecules, which in turn attract more water molecules. These form the branches of the snowflake. They are tiny. But the laws of the universe can be traced in snowflakes.
«Each flake takes a slightly different path. That's why no two snowflakes are alike.” Physics professor Brian Cox says it in the video “The Science of Snowflakes.”
In 1611, on a frosty January morning in Prague, a snowflake landed on the sleeve of mathematician Johannes Kepler's coat. This banal event led him to reflect: “Why do snowflakes have six sides?”
He concluded that this hexagonal pattern was the most efficient way to use space. Both in a hive comb and a pile of cannonballs. Or a delicate and ephemeral snowflake. It took 400 years for his theory to be proven.
Each water molecule (H2O) is made up of two hydrogen atoms and one oxygen atom. Water molecules clump together when they freeze. And the angle formed between hydrogen atoms is always approximately 105°. That's what gives us the six sides. The center of the snowflake is always hexagonal. But it can grow in all kinds of strange and extraordinary shapes.
The snowflakes are all radially symmetrical. You can divide them into identical portions, such as when you cut a cake. Shells, flowers and starfish share that symmetry. Even the Milky Way.
Each snowflake is a microcosm of the laws of physics. To begin with, they are not actually white but transparent. As they have many edges and these scatter light, this makes them look white. Electromagnetism determines its shape. When they freeze and form ice crystals, they acquire an electrical charge. And creates a magnetic field around each crystal.
The laws of the universe in snowflakes can be seen all around. Stars, solar systems, planets and ourselves. They are a microcosm that contains the universal laws of physics.