Elsewhere Lab

Field note 004 · Ice & pattern

Who shapes
a snowflake?

A tiny crystal. An intricate pattern. Follow the journey from the structure of ice to the branching shape you can hold on a glove.

Explore a growing snowflake
A translucent six-armed snow crystal with a hexagonal centre and delicate side branches
From our short · An illustrated snow crystal

01 · Predict

How do the arms grow alike?

Choose an idea. Then grow the crystal and test it.

Two H₂O moleculesStage 1 of 6
A snow crystal with six arms extending from the corners of a hexagonal plate

Solid: O–H bonds inside each molecule · Dashed: hydrogen bond

Water molecules connect.

Each H₂O molecule keeps its two solid O–H bonds. A weaker hydrogen bond reaches from the partly positive hydrogen of one molecule toward the partly negative oxygen of another.

Source: Caltech · Ice structure ↗

Make a prediction above, or explore without one.

One plate-like crystal, not every kind of snowflake. Growth, scale changes and vapour levels are illustrative. What this simplifies ↓

Use ← / → inside the player to change its six stages, or drag the growth slider. Reduced motion replaces playback with still stages.

02 · Compare two growth examples

Changing air starts a new crystal and returns you to the player. Both examples stay in a plate-forming regime. Press Play to compare.

03 · Look closer

The structure sets the symmetry.
The air shapes the details.

Not six neighbours.

Inside ordinary ice Ih, a water molecule has four nearest molecular neighbours. Six-membered rings occur within the larger, three-dimensional network. The sixfold symmetry is a property of that lattice—not six molecules surrounding every molecule.

Caltech · Crystal structure ↗

Not a carved hexagon.

Water molecules attach less readily to smooth faces than to rough spots. As a crystal grows, those slower-growing faces remain as facets. The plate is made of many repeating cells, not one enormous molecular ring.

SnowCrystals · Faceting ↗

Not a shared blueprint.

Projecting tips gain access to vapour and can develop branches. Temperature and water-vapour supply influence the details. Nearby arms experience similar conditions; they do not communicate to match their shapes.

SnowCrystals · Branching ↗ · Shared conditions ↗

04 · Take away

No tiny architect.
Just structure and growth.

Ice’s hexagonal lattice underlies sixfold symmetry. A crystal’s journey through the air shapes its branching pattern.

Scientific care

A window into the mechanism.

Bonding, then geometry

The opening shows explicit H₂O molecules and distinguishes solid internal O–H bonds from the dashed intermolecular hydrogen bond. The expanded ideal ice-Ih view then uses molecular centres and network connections; proton orientations are omitted. Tilting reveals its depth. The scale transition is illustrative.

A growth illustration

We progressively draw connected, faceted arms—not solve heat flow, diffusion or attachment kinetics. The vapour choices are qualitative examples, not measured humidity settings. No physical duration or crystal size is implied.

Nature is less tidy

Our arms have small differences, but remain deliberately orderly. Real snow includes plates, columns, irregular crystals and aggregates; the familiar star is only one form. More on snow-crystal diversity ↗

Prepared and source-checked 14 September 2026 · Report a correction by email ↗

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Sand arranged in a Chladni pattern on a vibrating plate