meridian
Let an agent explain meridians, relay geodesy, history, the prime meridian and surveying uses from geodetic and historical sources, describe the named meridian types, and distinguish meridians from parallels, time zones, the celestial meridian and traditional Chinese medicine meridians.
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 meridians, relay geodesy, history, the prime meridian and surveying uses from geodetic and historical sources, describe the named meridian types, and distinguish meridians from parallels, time zones, the celestial meridian and traditional Chinese medicine meridians.
In geography, a meridian or line of longitude is half of a great circle on the Earth s surface running from the North Pole to the South Pole, connecting points of equal longitude, measured east or west from the prime meridian, internationally agreed at Greenwich in 1884 and today realised as the IERS Reference Meridian about 102 metres east of the Greenwich transit circle; surveying systems use principal meridians, such as those of the US Public Land Survey System, and meridian markers show meridian lines on the ground. The term also names the celestial meridian in astronomy and, in traditional Chinese medicine, proposed energy channels, a distinct concept.
What it is for: Defining longitude and position.
It can be explain geodesy; relay history of the prime meridian; describe named meridian types; distinguish other senses.
Distinguishing features
Pole to pole
Longitude reference
Historical conventions
Several meanings
What it looks like
Lines running north-south on maps and globes; sometimes marked on the ground by plaques or lines.
Physical character
International Meridian Conference: 1884 year - Washington
IERS Reference Meridian offset: about 102 m - east of Airy transit circle
longitude range: 180 degrees east and west note
How it is recognised
Line of constant longitude from pole to pole
Meridian marker, prime meridian, principal meridian
Parallels are lines of latitude; time zones follow political boundaries; the celestial meridian is in the sky; TCM meridians are a medical tradition concept
Related models
is a kind of - in registry terms
defines -
includes -
is contrasted with -
In practice
Families and kinds
prime meridian
antimeridian
principal survey meridians
national historical prime meridians such as Paris
celestial meridian
Standards and regulation
International Earth Rotation and Reference Systems Service conventions
WGS 84
US Public Land Survey System
Failure modes and hazards
Confusing the Greenwich line and the IERS meridian
Confusing meridians and time zones
Presenting TCM meridians as anatomical structures
Also called
Where this came from
wikidata · CC0 1.0
Drafted structure
Bundle to layer to finding to question, as the second pass will find it: 4 bundles · 8 layers · 8 findings · 16 questions.
Understand What a meridian is.
Definition.
Definition
Definition.
Definition
Definition.
- What is a meridian, and how does it differ from parallels, time zones, the celestial meridian and TCM meridians? definition
- Is the question about geography, surveying, astronomy or traditional medicine? boundary
Types
Named types.
Types
Types.
- What are the prime meridian, principal meridians and meridian markers? definition
- Which entry fits the specific meridian? action
Geodesy Geodesy.
Science.
Longitude
Longitude.
Longitude
Longitude.
- How is longitude defined and measured? measurement
- Which references are standard? provenance
IERS
Reference meridian.
IERS
IERS.
- Why does the GPS zero meridian lie east of the Greenwich line? provenance
- Which sources are cited? provenance
History History.
Sources.
Conference
1884 conference.
Conference
Conference.
- How was Greenwich chosen in 1884, and which countries objected? provenance
- Which entry fits International Meridian Conference? action
Surveying
Survey meridians.
Surveying
Surveying.
- How are principal meridians used in land surveys? provenance
- Which entry fits Public Land Survey System? action
Context Other senses.
Context.
Astronomy
Celestial meridian.
Astronomy
Astronomy.
- What is the celestial meridian and meridian transit? provenance
- Which entry fits meridian (astronomy)? action
Traditional medicine
TCM meridians.
Traditional medicine
Traditional medicine.
- What are meridians in traditional Chinese medicine, and what does scientific evidence say, with positions attributed? provenance
- Which entry fits meridian (Chinese medicine)? action
What the second pass must settle
- Should the principal meridian be a separate entry?
- How should geodetic sources be linked?
- Should TCM meridians be disambiguated?