Pi
The number π is a mathematical constant, approximately equal to 3.14159, that is the ratio of a circle's circumference to its diameter.
At a glance
Key signals
0% cross fields · reaches 1 more
- Mathematics
- Geometry
- Explanation
- Examples
- Misconception
- Sourced relations 3
- Attribution
Dependencies
What this concept builds on and what it makes possible — derived from the atlas’s dependency, causal and structural relations, not from every related edge.
Enables · leads to
Circledepends onPiEstablished
circle depends on pi.
Mechanism: Every circle's circumference divided by its diameter equals pi — the same constant for all circles.
- Wikipedia (English & German editions) verifiedmoderate evidence
Circumferencedepends onPiEstablished
circumference depends on pi.
Mechanism: A circle's circumference depends on pi: it equals pi times the diameter, the constant ratio that holds for every circle.
- Wikipedia (English & German editions) verifiedmoderate evidence
System context
Piis aIrrational numberEstablished
pi is a kind of irrational number.
Mechanism: Pi is an irrational number: the ratio of a circle's circumference to its diameter, whose decimal never ends or repeats.
- Wikipedia (English & German editions) verifiedmoderate evidence
Structural role & consequence
Interpreted from the current atlas graph — what the connections mean, not just how many there are.
Currently dark in the atlas: 3 of 3 of its relations lack claim-level evidence.
atlas representation · Describes the current Thinking OS representation, not the state of the world.
Structural neighbourhood: 3 → 8 → 16 concepts reachable within 3 hops.
structural · Structural reach — being reachable is not the same as being understood.
All 3 of its relationships stay within its own discipline — a field-specific concept in the current atlas.
structural · Structural graph analysis — not a claim of importance, causation or history.
cross-field
3 within-field, 0 cross-field
Strengths & constraints
Constraints
- Evidence coverage currently thin in the atlas — few of its relationships carry claim-level evidence. atlas representation
Conditions
- Read structurally — most of its relationships carry no external evidence yet, so claims here are graph-derived. structural
Dependency radial
What this concept builds on (left) and what it makes possible (right) — derived from dependency and causal relations.
What builds on this
2 concepts build on this directly, 2 in total, across 2 disciplines.
Structural downstream reach along dependency edges — not a claim of historical necessity.
Seen through each discipline
How this concept sits in each of its fields — derived from its real connections in the graph, not asserted.
Through this lens it connects to Irrational number, Circle and Circumference.
Key dates
- c. 250 BCEFormalizationArchimedes bounds π between 3 10/71 and 3 1/7 in Measurement of a Circle. — MacTutor History of Mathematics Archive
Related ideas to explore
Concepts that look related but are not yet connected here — candidates for a connection to reason about, not established links.
- Connects 3 other ideas across 2 disciplines.
- Most of its connections are of the “Dependency” kind.
Derived from the graph’s real structure — observations, not a score.
Sources
- Wikipedia (English & German editions) verifiedmoderate evidence
- Wikidata verifiedmoderate evidence