Chronometric singularity

{{short description|Point at which time cannot be described mathematically}}

{{refimprove|date=April 2013}}

In theoretical physics, a chronometric singularity (also called a temporal or horological singularity) is a point at which time cannot be measured or described.

An example involves a time at a coordinate singularity, e.g. a geographical pole. Since time on Earth is measured through longitudes, and no unique longitude exists at a pole, time is not defined uniquely at this point. There is a clear connection with coordinate singularities, as can be seen from this example. In relativity, similar singularities can be found in the case of Schwarzschild coordinates.

Stephen Hawking once compared by a talk-show guest's question about "before the beginning of time" to asking "what's north of the North Pole".[http://www.wisegeek.com/what-is-cosmology.htm What is Cosmology?], wiseGEEK.com. Accessed 15 Feb 2013. In a related discussion, he mentions this again : [http://www.hawking.org.uk/the-beginning-of-time.html The Beginning of Time – Stephen Hawking] {{Webarchive|url=https://web.archive.org/web/20141006200729/http://www.hawking.org.uk/the-beginning-of-time.html |date=2014-10-06 }}; accessed 15 Feb 2013.