Cosmological redshift and distance inference
Spectral stretching carries expansion information but is not one universal distance ruler.
Key knowledge
Cosmological redshift describes the stretching of light wavelengths as the universe expands during propagation. Inferring a distance from redshift requires an expansion model and a definition of distance. A simple nearby Hubble relation is a limited approximation, rather than a universal conversion at all redshifts.
Conditions and scope
- Peculiar motions and gravitational shifts can also affect measured spectra.
- Luminosity, angular-diameter, comoving and light-travel distances differ; state the chosen model and distance measure.
Sources · 2
References
Sources retain their recorded scope. A source link alone does not establish verification of every statement.
Evidence and review
Source wavelength-stretching explanation and distance-law limitations.
2026-10-10 · Checked observed shift versus model-dependent distance; no fixed cosmological parameter value supplied.
Entry details
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- cosmos-redshift-distance
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- university-reference.1
- Structured reference record
- University reference