Back مسافة مسايرة Arabic Distància comòbil Catalan Çулташла инçĕш CV Kunmova distanco Esperanto Distancia comóvil Spanish Distantzia kohigikor eta propioak Basque فاصله همراه Persian Mukana liikkuva etäisyys Finnish Distance comobile French Distancia propia Galician
| Part of a series on |
| Physical cosmology |
|---|
 |
In standard cosmology, comoving distance and proper distance (or physical distance) are two closely related distance measures used by cosmologists to define distances between objects. Comoving distance factors out the expansion of the universe, giving a distance that does not change in time due to the expansion of space (though this may change due to other, local factors, such as the motion of a galaxy within a cluster).[1] Proper distance roughly corresponds to where a distant object would be at a specific moment of cosmological time, which can change over time due to the expansion of the universe. Comoving distance and proper distance are defined to be equal at the present time. At other times, the Universe's expansion results in the proper distance changing, while the comoving distance remains constant.
- ^ Huterer, Dragan (2023). A Course in Cosmology. Cambridge University Press. ISBN 978-1-316-51359-0.