longitude
Let an agent explain longitude and how it is defined and measured, relay history, conventions and reference meridians from geodesy and navigation sources, describe uses in mapping and time zones, and distinguish longitude from latitude, from local time and from celestial longitude.
Bundle → Layer → Finding → Questions Filled
4 bundles · 8 layers · 8 findings · 16 questions
Understand What longitude is.
Definition
Definition.
Definition
Definition.
- What is longitude, how is it measured from the prime meridian, and how does it differ from latitude? definition
- Is the question about geographic longitude, time, celestial coordinates or history? boundary
Conventions
Conventions.
Conventions
Conventions.
- How are east and west longitude, signed values and the 180th meridian handled? definition
- Which entry fits geographic coordinate system? action
Measure Measurement.
Modern
Modern measurement.
Modern
Modern.
- How do GNSS and geodetic datums determine longitude today? measurement
- Which references are standard? provenance
Historical
Historical measurement.
Historical
Historical.
- How were chronometers and lunar distances used to find longitude at sea? provenance
- Which sources are cited? provenance
Use Uses.
Mapping
Mapping and navigation.
Mapping
Mapping.
- How is longitude used in maps, charts and navigation? provenance
- Which entry fits navigation? action
Time
Time zones.
Time
Time.
- How does longitude relate to solar time and time zones? provenance
- Which entry fits time zone? action
Context History and beyond Earth.
History
History.
History
History.
- How was the longitude problem solved, from the Longitude Act to Harrison and the 1884 conference? provenance
- Which entry fits the history of longitude? action
Planets
Other bodies.
Planets
Planets.
- How is longitude defined on the Moon, Mars and the celestial sphere? provenance
- Which entry fits planetary coordinate system? action
Classifiers Filled
- Family
- Thing Registry
- Category
- Cross-cutting context
- Entry kind
- thing
- Plane
- XCT
- Domain
- XCT.QLT
- Other names and narrower kinds
- east longitude, ZGD
What it is Filled
The geographic coordinate that specifies east-west position on the Earth as an angle from the prime meridian at Greenwich, ranging from 0 to 180 degrees east and west, so that east longitude covers the Eastern Hemisphere, measured historically by chronometers and lunar distances and today by satellite positioning, and paired with latitude to locate any point; longitude also appears in celestial and planetary coordinate systems.
Why it exists Filled
Let an agent explain longitude and how it is defined and measured, relay history, conventions and reference meridians from geodesy and navigation sources, describe uses in mapping and time zones, and distinguish longitude from latitude, from local time and from celestial longitude.
Distinguishing features Filled
- Angular east-west coordinate
- Arbitrary prime meridian
- Time relation
- Historically hard to measure
What robots and AI may and may not do Filled
Must not
- Mix datums or formats in a way that misplaces a position.
- Swap latitude and longitude or drop the sign of east and west.
- Publish the precise position of a person, home or protected site without consent or need.
Only with a human decision
- Using a position for search and rescue or emergency dispatch.
May
- Convert and report longitude in degrees and the stated datum.
- Explain the prime meridian and the history of measuring longitude.
- Use coordinates to navigate within the area it is authorized to operate.
Moral aspects Filled
- Wrong coordinates can send rescuers or vehicles to the wrong place.
- Precise positions reveal where people live and where rare species or sites are.
Who is affected
- Navigators and travellers
- People whose location is shared
- Emergency responders
Owners Filled
Steward
Nobody owns the concept; geodetic agencies maintain the reference frames.
Links to other meta-models Filled
parent
- Q107715 - registry parent class
related
- physical quantity - in registry terms
- latitude - to locate points
- prime meridian - at Greenwich
- time zone - in principle
What else AI and robots need to interact with it Filled
Identity and identifiers required Filled
- Vercy registry: vr.tr.longitude
- Wikidata: Q36477 (https://www.wikidata.org/wiki/Q36477)
Direct properties not applicable Not applicable
- range: 0-180 degrees east and west
- prime meridian: Greenwich, IERS reference meridian note
- one degree at the equator: about 111 km
- Longitude Act: 1714 year - British prize
Plane XCT: no invented physical properties.
Recognition optional Filled
- East-west angular position from the prime meridian
- East and west longitude, 0 to 180 degrees
- Latitude is north-south; local time depends on longitude; celestial longitude is on the sky
- Not a visible object; meridian lines on a globe.
Capabilities and actions required Filled
- explain definition and conventions
- relay measurement and history
- describe uses
- distinguish related quantities
Hazards and failure modes required Filled
- Sign and hemisphere confusion
- Datum differences between historical and modern longitude
- Registry alias ZGD is an unclear code
Standards and interfaces required Filled
- IERS reference meridian and WGS 84
- ISO 6709 for coordinate representation
- International Meridian Conference of 1884
Context of use required Filled
- Locating east-west position.
- east longitude
- west longitude
- geodetic longitude in modern datums
- historical longitude from chronometers and lunar distances
- celestial and planetographic longitude
Sources Filled
- Wikidata item Q36477: longitude - identity and sense of the item
- Wikipedia: Longitude - general description of the item
Open questions
- Should prime meridian and the history of longitude be separate primary entries?
- How should geodesy sources be linked?
- The registry alias ZGD should be reviewed
Machine files
Provenance
thing registry research (pass 2) · unreviewed
Built from: models/things/publications/thing-q36477/spec.json