meridian
Earth's longitudinal line
Meridian has meanings that cluster around the idea of a defining line or peak.
In geography, a meridian is an imaginary line running from pole to pole, marking longitude: the prime meridian passes through Greenwich.
In astronomy, the celestial meridian is where the sun reaches its highest point at noon.
From this comes the figurative sense of a peak or zenith: the meridian of his career.
In traditional Chinese medicine, meridians are pathways through which vital energy flows.
Day's exact middle
- middayTwelve hours after midnight
- solar noonSun at peak altitude
- sunEarth's primary star
- highest pointMaximum elevation or level
shadow · sundial · transit · local time · solar time · passage · culmination · southing
London district, meridian origin
- longitudeEast-west angular distance
- latitudeGeographic or personal freedom
- equatorMidpoint circle of rotation
- International Date LineLongitude where calendar shifts
hemisphere · time zones · GMT · UTC · east · west · coordinate · degrees
Midpoint circle of rotation
- eclipticSun's apparent annual path
- celestial sphereImaginary dome of stars
- GreenwichLondon district, meridian origin
- latitudeGeographic or personal freedom
longitude · declination · coordinate · celestial equator · sky map · star chart · transit · observatory
Point straight overhead
- apexUppermost point or culmination
- pinnacleUtmost summit or spire
- climaxPoint of greatest intensity
- acmeUltimate point of attainment
culmination · summit · height · apogee · high point · prime · crowning moment · maturity
Measuring and charting terrain
- triangulationLocation via three points
- datumSingle unit of information
- geoidGravitational equipotential surface model
- theodolitePrecision angle-measuring instrument
GPS · GIS · latitude · longitude · ellipsoid · reference frame · benchmark · geodetic
Vital life energy
- energyPower to do work
- channelsPaths for transmission
- pathwaysRoutes for walking
- traditional Chinese medicineAncient Eastern healing system
acupressure · needles · acupoints · flow · blockage · yin · yang · five elements
noon
Day's exact middle
- middayTwelve hours after midnight
- solar noonSun at peak altitude
- sunEarth's primary star
highest point · shadow · sundial · transit · local time · solar time · passage · culmination · southing
Greenwich
London district, meridian origin
- longitudeEast-west angular distance
- latitudeGeographic or personal freedom
- equatorMidpoint circle of rotation
International Date Line · hemisphere · time zones · GMT · UTC · east · west · coordinate · degrees · map
equator
Midpoint circle of rotation
- eclipticSun's apparent annual path
- celestial sphereImaginary dome of stars
- GreenwichLondon district, meridian origin
latitude · longitude · declination · coordinate · celestial equator · sky map · star chart · transit · observatory · astronomer
zenith
Point straight overhead
acme · culmination · summit · height · apogee · high point · prime · crowning moment · maturity · crest
surveying
Measuring and charting terrain
- triangulationLocation via three points
- datumSingle unit of information
- geoidGravitational equipotential surface model
theodolite · GPS · GIS · latitude · longitude · ellipsoid · reference frame · benchmark · geodetic · mapping
qi
Vital life energy
traditional Chinese medicine · acupressure · needles · acupoints · flow · blockage · yin · yang · five elements · shiatsu
- Knot Theoryunknot, figure-eight knot, link, linking number, braid
- Islamic Astronomyastrolabe, star catalog, observatory, House of Wisdom, celestial globe
- Earthearth, Earth, globe, continent, axis
- geographycontinents, continent, oceans, countries, country
- Worldearth, globe, planet, continents, continent
- astronomy termseclipse, solar eclipse, lunar eclipse, star, meteor shower
meridianparallel
Equidistant at all points
latitude · equator · tropic · horizontal line · latitude line
- prime meridianZero-degree longitude line
- Greenwich meridianZero-degree longitude line