6. As evidence supporting the Big Bang Theory, what does the redshift of light from galaxies indicate?
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2 points
the universe is mainly hydrogen
the universe is 13.8 billion years old
the universe is expanding
the universe is cooling off
The redshift of light from galaxies indicates that the universe is expanding.
The redshift of light from galaxies indicates that the universe is expanding.
The redshift of light from galaxies indicates that the universe is expanding. To understand this, let's break it down:
1. Start with the understanding that light is made up of waves.
2. When an object is moving away from us, the light waves emitted by that object get stretched out, which means their wavelengths get longer.
3. The longer wavelengths of light appear more towards the red end of the spectrum (hence the term "redshift").
4. Conversely, when an object is moving towards us, the light waves get compressed, resulting in shorter wavelengths, which appear more towards the blue end of the spectrum (known as "blueshift").
Now, in the context of the Big Bang Theory:
1. The Big Bang Theory suggests that the universe originated from an incredibly hot, dense state.
2. According to this theory, the universe has been expanding ever since the Big Bang event.
3. As the universe expands, galaxies move away from each other.
4. This movement causes the light emitted by galaxies to undergo redshift, meaning that the wavelengths of the light get stretched out due to the expansion of space.
Therefore, the redshift of light from galaxies provides strong evidence for the expansion of the universe, which supports the Big Bang Theory. This finding allows scientists to estimate the age of the universe, which is approximately 13.8 billion years old. Additionally, the expansion of the universe leads to the conclusion that it is cooling off over time. However, the redshift does not provide direct evidence for the composition of the universe or the abundance of hydrogen.