| The Columbia Encyclopedia, Sixth Edition. 2001-07. |
| |
| prime meridian |
| |
| |
| meridian that is designated zero degree (0°) longitude, from which all other longitudes are measured. By international convention, it passes through the original site of the Royal Observatory in Greenwich, England; for this reason, it is sometimes called the Greenwich meridian. Universal time, the standard basis for determining time throughout the world, is civil time measured at the prime meridian. |
| |
| | | The Columbia Encyclopedia, Sixth Edition. Copyright © 2007 Columbia University Press. |
|
|
