Principles of Physical Cosmology

Description

Aristotle's Aether and Contemporary Science by Christopher A. Decaen:

111. A "metric" is possessed by a slice of space (or, in general relativity, space-time) describable by an equation incorporating infinitesimal differences between its endpoints. If a metric is a "tensor," it allows the components of the system or equation to be transformed from one set of endpoints to another; thus it plays the central role in general relativity of defining the geometry of space-time and giving the prescription for integrals and derivatives. (Where the space is not flat, it is said to be permeated by a "tensor field.") For an in-depth account of general relativity's metric tensor, see P. J. E. Peebles, Principles of Physical Cosmology (Princeton: Princeton University Press, 1993), 227-44.