The apparent recessional velocities of galaxies at large distances are due mainly to
A) the actual motions of the galaxies through space.
B) the motion of our Sun around the galactic center.
C) a continuously increasing scaling factor of the universe.
D) the relativistic jets launched by supermassive black holes.
E) incorrect interpretation of spectra from galaxies.

Question

Quizplus · Accepted Answer

The apparent recessional velocities of galaxies are primarily due to the expansion of the universe, which is described by a continuously increasing scaling factor in cosmology. This is known as the metric expansion of space, where galaxies appear to move away from us as space itself expands.

The Apparent Recessional Velocities of Galaxies at Large Distances Are