In [[inflation (cosmology)|standard inflationary cosmological models]], the redshift of cosmological bodies is ascribed to the expansion of the universe, with greater redshift indicating greater [[cosmic distance ladder|cosmic distance]] from the Earth (see [[Hubble's Law]]). This is referred to as [[cosmological redshift]]. Ruling out errors in measurement or analysis, quantized redshift of cosmological objects would either indicate that they are physically arranged in a quantized pattern around the Earth, or that there is an unknown mechanism for redshift unrelated to cosmic expansion, referred to as "intrinsic redshift" or "non-cosmological redshift".
In 1973, astronomer [[William G. Tifft]] was the first to report evidence of this pattern. RecentSubsequent discourse has focused upon whether [[redshift survey]]s of [[quasars]] (QSOs) have produced evidence of quantization in excess of what is expected due to [[selection effect]] or [[galaxy cluster|galactic clustering]].<ref>{{cite journal |last1=Trimble |first1=V. |last2=Aschwanden |first2=M. J. |last3=Hansen |first3=C. J. |date=2007 |title=Astrophysics in 2006 |journal=[[Space Science Reviews]] |volume=132 |issue=1 |pages=1–182 |doi=10.1007/s11214-007-9224-0 |arxiv=0705.1730|bibcode = 2007SSRv..132....1T }}</ref><ref name="adsabs.harvard.edu">{{cite journal |last1= Bell |first1=M. B. |last2=McDiarmid |first2=D. |date=2006 |title=Six Peaks Visible in the Redshift Distribution of 46,400 SDSS Quasars Agree with the Preferred Redshifts Predicted by the Decreasing Intrinsic Redshift Model|journal=[[Astrophysical Journal]] |volume=648 |issue=1 |pages=140–147 |bibcode=2006ApJ...648..140B |doi=10.1086/503792|arxiv = astro-ph/0603169 }}</ref><ref>{{cite journal |last1=Godłowski |first1=W. |last2=Bajan |first2=K. |last3=Flin |first3=P.|date=2006 |title=Weak redshift discretisation in the Local Group of galaxies? |journal=[[Astronomische Nachrichten]] |volume=387 |issue=1 |pages=103 |bibcode=2006AN....327..103G |doi=10.1002/asna.200510477|arxiv = astro-ph/0511260 }}</ref><ref name=Tang>{{cite journal |last1=Tang |first1=S. M. |last2=Zhang |first2=S. N. |date=2005 |title=Critical Examinations of QSO Redshift Periodicities and Associations with Galaxies in Sloan Digital Sky Survey Data |journal=[[Astrophysical Journal]]|volume=633 |issue=1 |pages=41–51 |bibcode=2005ApJ...633...41T |doi=10.1086/432754 |arxiv=astro-ph/0506366}}</ref>
The idea has been on the fringes of astronomy since the mid-1990s and is now discounted by the vast majority of astronomers, but a few scientists who espouse [[nonstandard cosmology|nonstandard cosmological models]], including those who reject the [[Big Bang]] theory, have referred to evidence of redshift quantization as reason to reject conventional accounts of the origin and evolution of the [[universe]].<ref>For examples, see references by nonstandard cosmology proponents
