Redshift Velocity Calculator
Estimate a galaxy's recession velocity from its cosmological redshift using the classical approximation v = z * c.
Velocita di Recessione
2,997.92 km/s
Hubble Distance (approx)42.83 Mpc
Recession Velocity vs Redshift (z)
Formula
## Redshift and Recession Velocity For low redshifts (z << 1): **v = z × c** where c = 299 792.458 km/s Combined with Hubble's law v = H0 d gives approximate distance d = v / H0. For z > 0.3, relativistic corrections are important.
Esempio Risolto
A galaxy has redshift z = 0.01.
- 01v = 0.01 × 299 792.458 = 2 998 km/s
- 02d ≈ v / H0 = 2998 / 70 = 42.8 Mpc
- 03About 140 million light-years.
Domande Frequenti
What causes cosmological redshift?
The expansion of space stretches photon wavelengths in transit. It is not a classical Doppler effect.
When does the classical formula break down?
For z > 0.3 use the relativistic Doppler formula; for z > 1 use full cosmological models.
What is the highest observed redshift?
The cosmic microwave background has z ≈ 1100. The most distant galaxies observed have z > 10.