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Research draft

radius

vr.tr.radius · XCT.QLT

Let an agent explain and compute radii in geometry and applications, distinguish specialised radii, and separate the anatomical sense.

Thing Registry Cross-cutting context

Research draft, second pass

A second pass drafted this model: the structure a model of this thing needs, and what is known about it in the world. The line under this one says how the second half was obtained - researched against sources, or recalled without web access, in which case nothing here was read anywhere and every claim is a lead to verify. Unreviewed either way.

written by Claude from model knowledge without web access - no source was read, every claim is a lead to verify

Researched by: Claude

Purpose and description

Let an agent explain and compute radii in geometry and applications, distinguish specialised radii, and separate the anatomical sense.

A line segment from the centre of a circle or sphere to its boundary, and the length of that segment, half the diameter, extended to related measures such as the radius of curvature of a curve, the radius of a pipe or shaft, and specialised radii such as the Schwarzschild radius and minimum bend radius; the radius is fundamental to geometry, engineering and physics, and is also the name of a forearm bone.

What it is for: Geometry, engineering and physics.

It can be compute radii from other measurements; explain radius of curvature and specialised radii; apply radius in engineering specifications; separate the anatomical sense.

Distinguishing features

Centre-to-boundary length

Defines circles and spheres

Many specialised forms

Homonym with the bone

What it looks like

Not physical; a length in diagrams and specifications.

How it is recognised

Centre to boundary

Half the diameter

The radius bone is a separate anatomical sense

Related models

is a kind of - category

line segment

is a kind of - category

length

is related to - circumradius and inradius

triangle

is related to - horizon radii

Reissner-Nordstrom black hole

In practice

Families and kinds

radius of circles and spheres

radius of curvature

engineering radii such as pipe, shaft and bend radii

physical radii such as the Schwarzschild radius

atomic and ionic radii

Standards and regulation

ISO 80000-2 and 80000-3 notation

Engineering standards for bend radii and fillets

Failure modes and hazards

Confusing radius and diameter

Ignoring minimum bend radius in cables and pipes

Confusing senses

Also called

radius of curvatureSchwarzschild radiusminimum bend radiuspipe radiusshaft radiusinner annulus radiusouter annulus radiusradial coordinategyroradiuseffective radiusmean radiusPotato radiusouter radiusinner radiusminimum railway curve radiusparticle horizonturning radiushydrodynamic radiusMolière radiusnuclear radiuscircumradiusinradiushydraulic radiusship's turning circleatomic radiusblast radiusEinstein radiusJeans lengthscrub radiusexradiusvan der Waals radiuscovalent radiusionic radius

Where this came from

wikidata · CC0 1.0

Source repository Registry entry point

Also registered as vr.tr.radius

Drafted structure

Bundle to layer to finding to question, as the second pass will find it: 4 bundles · 8 layers · 8 findings · 16 questions.

Compute Finding the radius.

From other measures.

Circle

Circles and spheres.

Circle

Circles.

  1. What is the radius given the diameter, circumference, area or volume? measurement
  2. How does the radius enter these formulas? definition

Curvature

Radius of curvature.

Curvature

Curvature.

  1. What is the radius of curvature of this curve or surface at this point? measurement
  2. How does it relate to curvature? definition
Apply Engineering radii.

Specifications.

Bend

Minimum bend radius.

Bend

Bend radius.

  1. What minimum bend radius applies to this cable, pipe or sheet, according to the standard? provenance
  2. What happens if it is exceeded? boundary

Parts

Radii on parts.

Parts

Parts.

  1. How are radii specified on drawings for shafts, fillets and pipes? provenance
  2. Which tolerances apply? measurement
Physics Physical radii.

Specialised radii.

Schwarzschild

Schwarzschild radius.

Schwarzschild

Schwarzschild radius.

  1. What is the Schwarzschild radius, and what is it for this mass? measurement
  2. What does it mean physically? definition

Atomic

Atomic and ionic radii.

Atomic

Atomic radii.

  1. How are atomic and ionic radii defined and measured? definition
  2. How do they vary across the periodic table? provenance
Senses Disambiguation.

Radius has other senses.

Bone

The radius bone.

Bone

Anatomical sense.

  1. Is the forearm bone meant? boundary
  2. Which entry fits? action

Teach

Teaching.

Teach

Teaching.

  1. How can radius and diameter be taught without confusion? action
  2. Which misconceptions arise? provenance

What the second pass must settle

  • Should radius of curvature be a separate entry?
  • How should engineering standards be linked?
  • How should the anatomical sense be split?
Draft as JSON