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. This is one of the key pieces of evidence supporting the Big Bang Theory. The redshift occurs because the universe is expanding, causing the wavelengths of light to stretch as they travel through space. This stretching of light wavelengths results in a shift towards the red end of the electromagnetic spectrum. Therefore, the observation of redshift in the light from galaxies strongly suggests that the universe is indeed expanding.
To understand how scientists determine the age and other characteristics of the universe using the redshift, they use a principle called Hubble's Law. This law states that the speed at which galaxies are moving away from us is directly proportional to their distance from us. By measuring the redshift of light from various distant galaxies, scientists can calculate how fast these galaxies are moving away from us and, consequently, estimate their distance.
By combining measurements of distance and velocity, scientists have determined that the universe has been expanding for approximately 13.8 billion years. This is how researchers have arrived at the estimated age of the universe. The concept of the universe cooling off is related to the expanding nature of the universe. As the universe expands, it becomes less dense and consequently cools down. Therefore, the observation of the redshift of light from galaxies provides strong evidence supporting the ideas that the universe is expanding, cooling off, and is approximately 13.8 billion years old.