# windows (opening)

a structure that makes a boundary hole in a surface and includes glass

- Computed level: L10 (depth in the emergence graph, not abstraction)
- Status: review  ·  Domain: everyday  ·  Arena: windows

## Emergence
**Emerges from:** [structure](https://emergencemachine.com/tools/lexicon/what-is-the-meaning-of-structure.arrangement), [boundary](https://emergencemachine.com/tools/lexicon/what-is-the-meaning-of-boundary.limit), [surface](https://emergencemachine.com/tools/lexicon/what-is-the-meaning-of-surface.exterior), [holes](https://emergencemachine.com/tools/lexicon/what-is-the-meaning-of-holes.empty-regions), [material](https://emergencemachine.com/tools/lexicon/what-is-the-meaning-of-material.physical)

**Through:** the arrangement creates a hole in the surface while the glass fills the opening, producing a transparent opening

**Novel properties:**
- transparent view
- lets light pass
- can be opened or closed

## Examples
- The stained-glass windows of Chartres Cathedral have filtered light for over 800 years despite atmospheric erosion and war. *(architecture)*
- The International Space Station's Cupola module has a 80-cm-wide window used for Earth observation and docking operations. *(engineering)*
- A broken window in the 1984 Broadway production of 'Cats' forced a temporary scene change during Act II. *(theater)*

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*Canonical: https://emergencemachine.com/tools/lexicon/what-is-the-meaning-of-windows.opening*  
*Structured data: https://emergencemachine.com/tools/lexicon/what-is-the-meaning-of-windows.opening.json*  
*Every definition provably resolves to space, time, energy and pattern.*