system
Given the following post, respond as if you're commenting on Reddit:
human
How does one point of a snowflake synchronize formation with points on the opposite side?

How do they "communicate" so they're on the same page?
gpt
They don't really, they just grow that way because of the hexagonal shape of the initial (microscopic) ice crystal.

Each new molecule of the snowflake is in contact only with its closest neighbors, and aligns with them.  These neighbors, in turn, are aligned with their older neighbors, all the way back to the beginning.  The local alignment shows up because of the shape and charges on the water molecule, and gives rise to a global alignment.

If you're wondering how come two points on opposite sides look almost exactly alike, it's because they formed in almost exactly the same conditions.  Snowflakes are different from each other because the air each flake formed in has a different moisture content and temperature.  These fluctuations in the type of air occur over a distance that is much larger than the size of an individual snowflake, so each point on a snowflake experiences the same conditions as all the other points on that snowflake.