This photo resembling a forest scene is actually a layer of frost on a window. When air is supersaturated with water vapour, water molecules attach themselves on a particle of dust, dirt, or a scratch on a glass surface that is below the freezing point of water. This central particle of dirt, or other irregularity, begins the growth of ice crystals on the surface, which eventually form intricate and beautiful frost patterns. Like a magnet, water molecules are slightly more positive on one side and slightly more negative on the other. As a result, water molecules arrange themselves in structures that provide minimal repulsion between similarly-charged ends. These arrangements result in the formation of crystals.

One crystal structure that appears in the photo is the dendritic (tree-like) structure that resembles fern branches. Crystal structures vary with temperature and the quantity of moisture in air, to give an infinite number of different patterns. Basic dendritic growth forms branches at 60-degree angles in perfect conditions, due to the hexagonal structure of ice crystals. On this window, like every other one, dirt, dust, and scratches deflect the branches and bumps in the window to form beautiful tree-like patterns.

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Nickolay Lasenko
St. Elizabeth Catholic High School, Richmond Hill, Ontario
1st Prize ( High School/CEGEP )

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