The redshift of the galaxies is correctly interpreted as:
A)a Doppler shift due to the random motions of galaxies in space.
B)an aging of light as gravity weakens with time.
C)space itself is expanding with time, so the photons are stretched while they travel throughspace.
D)placing our Galaxy near the center of the Local Group.
E)the differences in temperatures and star formation in old and young galaxies.

Question

Quizplus · Accepted Answer

The redshift of galaxies is interpreted as a result of the expansion of space itself, also known as cosmological redshift. As the photons of light travel through expanding space, they get stretched out, causing their wavelength to increase and their frequency to decrease, resulting in a redshift. This phenomenon is not due to the random motions of galaxies or aging of light, but is a fundamental consequence of the expansion of the universe. The redshift of galaxies is due to the stretching of photons as they travel through expanding space, known as cosmological redshift. This effect is not caused by the random motions of galaxies or the aging of light with weakening gravity. Placing our Galaxy near the center of the Local Group or differences in temperatures and star formation in old and young galaxies are not relevant to the interpretation of redshift.

The Redshift of the Galaxies Is Correctly Interpreted As