# back (spatial)

a side of a thing that is part of its boundary

- Computed level: L13 (depth in the emergence graph, not abstraction)
- Status: review  ·  Domain: spatial  ·  Arena: back

## Emergence
**Emerges from:** [side](https://emergencemachine.com/tools/lexicon/what-is-the-meaning-of-side.surface), [part](https://emergencemachine.com/tools/lexicon/what-is-the-meaning-of-part.relation), [boundary](https://emergencemachine.com/tools/lexicon/what-is-the-meaning-of-boundary.limit), [relevance](https://emergencemachine.com/tools/lexicon/what-is-the-meaning-of-relevance.core)

**Through:** the side of a thing that is part of its boundary is a different side when relevance shifts its status

**Novel properties:**
- positioned opposition
- contextual prominence
- asymmetrical salience

## Examples
- The back of the 1986 Voyager 2 spacecraft housed thrusters and power systems, shielded during planetary flybys. *(engineering)*
- Willow leaves in the Amazon rainforest orient their backs downward to reduce water absorption during storms. *(biology)*
- The back of the Berlin Wall, facing East German guards, remained inaccessible to Western observers for 28 years. *(institutions)*

## Used by
- [deal](https://emergencemachine.com/tools/lexicon/what-is-the-meaning-of-deal.transaction) (L14)
- [feedback](https://emergencemachine.com/tools/lexicon/what-is-the-meaning-of-feedback.communication) (L14)
- [return](https://emergencemachine.com/tools/lexicon/what-is-the-meaning-of-return.movement) (L14)
- [tipping point](https://emergencemachine.com/tools/lexicon/what-is-the-meaning-of-tipping-point.irreversible) (L15)

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