As evidence supporting the Big Bang theory, what does the redshift of light from galaxies indicate?
a
The universe is mainly hydrogen
b
The universe is cooling off.
c
The universe is expanding.
d
The universe is 13.8 billion years old.
c
The universe is expanding.
c
The redshift of light from galaxies indicates that the universe is expanding.
The correct answer is c) The redshift of light from galaxies indicates that the universe is expanding.
To understand why the redshift of light from galaxies indicates an expanding universe, we need to consider a phenomenon called the Doppler effect. When an object is moving away from an observer, the wavelength of the light emitted by that object appears stretched or "shifted" towards the longer (or redder) end of the spectrum. This is known as a redshift.
When we observe light from distant galaxies, we find that the light has been redshifted. This means that the galaxies are moving away from us, and the amount of redshift is directly related to their distance from us. The farther away a galaxy is, the greater its redshift.
This observation of redshifted light from galaxies led to the development of the Big Bang theory, which suggests that the universe is expanding from a highly dense and hot state. The redshift of light from galaxies provides evidence that the space between galaxies is stretching, causing galaxies to move away from each other.
Therefore, the redshift of light from galaxies strongly supports the idea that the universe is expanding.