Why/How do snowflakes grow symmetrically?

Answer 1

Having seen more than my share of photographs of snowflakes, I recently noticed that most seem to be perfect mirror images. How can the spines on ONE side of the flake possibly know what random shapes those on the OTHER are assuming in an essentially random freezing environment? Why would not all snowflakes be non-symmetrical masses of frozen material with absolutely NO symmetry whatsoever?

What makes those pretty, feathery patterns in the frost on windows during winter?

Scientists have been studying snowflakes since the early 1600s, and while we don't know everything about how they form, we know a lot, a fair amount of which I've conveyed in this column over the years. However, since many of the Teeming Millions weren't yet alive in 1973, you'll excuse a brief review.

As water vapor rises into the colder upper atmosphere it cools, and when chilled enough condenses into infinitesimal water droplets, which commonly form around particles of dust, sea salt, etc, known as nucleation sites. If the temperature keeps dropping, eventually the droplets freeze into ice crystals. These crystals start out as tiny hexagonal prisms — the hex shape resulting from the angle formed between oxygen atoms as the frozen water molecules line up. Under the right conditions, additional moisture condenses directly onto the crystal and freezes too. Since the corners where the crystal faces meet project further into the surrounding vapor than the flat sides, they accumulate ice faster, typically producing the familiar six-branched snowflake.

Why are the branches identical? They're not always, or even usually, as you'll discover if you examine a few actual flakes. The impressive symmetrical specimens you see in books were selected for their photogenic qualities, possibly by Vermont farmer Wilson Bentley, who published a volume of more than 2,400 snowflake images in 1931. Symmetry admittedly is pretty common, but there's nothing magical about it. Crystal formation isn't random but rather is rigidly dependent on temperature, density of water vapor, and other local conditions, all of which are likely to be uniform in the immediate neighborhood of the flake — what happens to one branch happens to the rest. I'm tempted to say spinning of the budding crystal as it falls contributes to symmetry, just as wet clay spinning beneath the potter's hand on a wheel tends to assume a uniform shape, but absent experimental corroboration we'll consign this conjecture to the drawer.

Frost on windows forms under different conditions than in a cloud — typically temperature and pressure are higher and, more important, the ice collects on a surface that may be dirty or rough instead of what for practical purposes is a dimensionless point in the air. As a consequence symmetry is rare. Still, the basic angle inherent in ice molecules imposes some structure on frost formation, which manifests itself in those feathery patterns you see on winter windowpanes or (I bet Pete knows this) chilled beer glasses, which is a lucky thing from the standpoint of scientific study, since they're much more interesting to look at when catalyzed with C2H5OH.

Answer 2

Their fundamental form derives from the arrangement of the water molecules in the ice crystal. When a liquid freezes, the molecules tend to settle in the lowest-energy state, and that almost always involves some form of symmetry. The higher the symmetry, the more stable the crystal is.

Answer 3

through fact snowflake toddlers are accompanied, they does not be genetically with regards to their siblings. Scientifically there may well be no project. Legally it would probable be desperate by making use of the state they stay in.