Word origin · etymology
Greek through Medieval Latin.
Greek epoche meant a stopping or fixed point; astronomy uses epoch for a fixed reference instant.
How we know · epistemology
Model reference convention
An epoch anchors positions or model parameters to an instant. It must be read with the associated frame and motion model; it does not necessarily identify when an observation was made.
Connected concepts
Mentioned in 8 other entries
These links connect subjects and terminology. They do not establish a shared historical origin.
Sources & provenance
Use the citations beside each section to distinguish a calculation convention, a historical teaching and an editorial example.