Geocentric Coordinate Time Geocentric Coordinate Time Geocentric Coordinate Time (TCG - Temps-coordonnée géocentrique) is a coordinate time standard intended to be used as the independent variable of time for all calculations pertaining to precession, nutation, the Moon, and artificial satellites of the Earth. It is equivalent to the proper time experienced by a clock at rest in a coordinate frame co-moving with the center of the Earth: that is, a clock that performs exactly the same movements as the Earth but is outside the Earth's gravity well. It is therefore not influenced by the gravitational time dilation caused by the Earth. TCG was
Amherst Central Business District Amherst Central Business District The Amherst Central Business District is a historic district encompassing the heart of downtown Amherst, Massachusetts. Centered on the northern section of the long town common, the area has been the civic and commercial heart of the town since the 18th century. The district was listed on the National Register of Historic Places in 1991, and slightly enlarged in 2011. Amherst was originally part of Hadley, settled in 1661, and was itself known to have colonial settlements by 1728. It was incorporated in 1768. Its earliest focal point of settlement was in what is now its