# wheel (tool)

A round piece that moves around a center to carry a thing.

- Computed level: L15 (depth in the emergence graph, not abstraction)
- Status: review  ·  Domain: everyday  ·  Arena: wheels

## Emergence
**Emerges from:** [piece](https://emergencemachine.com/tools/lexicon/what-is-the-meaning-of-piece.portion), [motion](https://emergencemachine.com/tools/lexicon/what-is-the-meaning-of-motion.movement), [center](https://emergencemachine.com/tools/lexicon/what-is-the-meaning-of-center.location), [carrying](https://emergencemachine.com/tools/lexicon/what-is-the-meaning-of-carrying.transporting), [round](https://emergencemachine.com/tools/lexicon/what-is-the-meaning-of-round.shape), [space](https://emergencemachine.com/tools/lexicon/what-is-the-meaning-of-space.extent)

**Through:** The round piece rotates around its center, producing motion that transports a thing in contact and under control.

**Novel properties:**
- rotating transport
- controlled circular motion
- centered rotation with load

## Examples
- The London Eye rotates once every 30 minutes, carrying 32 capsules around its central hub. *(engineering)*
- A potter shapes wet clay on a kick-wheel spinning at 60 revolutions per minute in Jingdezhen, China. *(craft)*
- The O-ring seal in the Space Shuttle Challenger's solid rocket booster failed at 73 seconds into flight. *(disaster)*

## Used by
- [auto](https://emergencemachine.com/tools/lexicon/what-is-the-meaning-of-auto.vehicle) (L17)
- [car](https://emergencemachine.com/tools/lexicon/what-is-the-meaning-of-car.transport) (L16)
- [cart](https://emergencemachine.com/tools/lexicon/what-is-the-meaning-of-cart.transport) (L16)

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