7 articles for "Prime"

The great circle that passes through the Earth's poles and the Old Observatory at Greenwich, England. This is the basic reference circle for longitudes on the Earth, and for the distribution of time signals.

See also:
♦ Greenwich ♦ Great Circle

The Meridian or Hour Circle which passes throughGreenwich, England, from where all terrestrial longitude is measured.

See also:
♦ Greenwich ♦ Great Circle

The great circle which passes through the East and West points of the Horizon, and the Zenith and Nadir of a particular location. The Prime Vertical is perpendicular to both the Horizon and the Meridian.

See also:
♦ East Point ♦ Great Circle ♦ Horizon ♦ Zenith ♦ Nadir ♦ Meridian

The great circle that passes through the east point, and its diametrical opposite, the west point (both points are located on the horizon), as well as through the zenith and its diametrical opposite, the nadir. It is perpendicular to both the horizon and the meridian.

An observer standing upright and facing south would be standing in the plane of the prime vertical.

See also:
♦ East Point ♦ Great Circle ♦ Horizon ♦ Zenith ♦ Nadir ♦ Meridian

A great circle of the Celestial Sphere used in theHorizon system of coordinates and formed at the intersecting points of a circle drawn through the Zenith, Nadir, and the East and the West points of the Horizon.

See also:
♦ East Point ♦ Great Circle ♦ Horizon ♦ Zenith ♦ Nadir ♦ Meridian

The vertical circle that lies at right angles to the meridian, and passes through the East point, Zenith, West point and Nadir of any place.

See also:
♦ East Point ♦ Great Circle ♦ Horizon ♦ Zenith ♦ Nadir ♦ Meridian

A variation of the Prime Vertical Mundoscope used by Michael Erlewine for relocation work, which places the zero-point at the East Point of the Horizon, rather than at the Upper Meridian.

See also:
♦ Erlewine, Michael ♦ East Point ♦ Horizon ♦ Meridian