6. As evidence supporting the Big Bang Theory, what does the redshift of light from galaxies indicate? *
2 points
d the universe is mainly hydrogenthe
c universe is expanding
b the universe is cooling off
a the universe is 13.8 billion years old
c the universe is expanding
To determine which option among a, b, c, or d is the correct answer, we need to understand what the redshift of light from galaxies indicates.
The redshift phenomenon is observed when light from distant galaxies appears to be shifted towards longer wavelengths, towards the red end of the spectrum. This effect was first noticed by astronomer Edwin Hubble in the 1920s.
The key concept connected to the redshift of light is the Doppler effect. The Doppler effect is the change in frequency or wavelength of a wave as perceived by an observer when the source of the wave and the observer are moving relative to each other. In the case of light, when a source is moving away from an observer, the light waves get stretched out and appear as redshifted.
Astronomers found that almost the entire universe is experiencing a redshift, indicating that galaxies are moving away from us. This observation led to the formulation of the Big Bang Theory. According to the Big Bang Theory, the redshift of light from galaxies indicates that the universe is expanding.
Therefore, the correct answer is option c: the universe is expanding.