If the redshift is interpreted as a Doppler shift, the recessional velocity of the object can be calculated.

When the recessional velocities are plotted against these distances, a linear relationship known as Hubble's law is observed:

Scientists use the redshift to gauge both the recessional velocity of an object and its distance from Earth.

Hubble is known for showing that the recessional velocity of a galaxy increases with its distance from the earth, implying the universe is expanding.

Hubble's law is considered a fundamental relation between recessional velocity and distance.

The relation of redshift to recessional velocity is another matter.

Next, the connection between redshift or redshift velocity and recessional velocity is discussed.

The redshift is usually interpreted as due to recessional velocity, which can be calculated according to the formula:

The recessional velocity of a galaxy is usually calculated from the redshift observed in its emitted electromagnetic radiation.

Column 8: The recessional velocity (km/s) of the galaxy relative to the cosmic microwave background.