Question

which evidence supports the idea that CMB radiation is a remnant of the big bang?
its mass is uniform
its temperature is uniform
its mass fluctuates greatly
its temperature fluctuates greatly

Answer 1

The evidence that supports the idea that CMB radiation is a remnant of the Big Bang is primarily related to its temperature and uniformity.

1. Temperature uniformity: The Cosmic Microwave Background (CMB) radiation has a nearly perfect uniform temperature across the entire observable universe, with only small, random fluctuations. This uniform temperature of approximately 2.7 Kelvin (-270.45 degrees Celsius) is consistent with the predictions of the Big Bang theory, as it suggests that the universe was once in a highly homogeneous state that expanded and cooled uniformly.

2. Uniform mass distribution: The mass distribution of the universe does not directly support the idea that CMB radiation is a remnant of the Big Bang. The CMB radiation itself does not have mass; it is simply electromagnetic radiation. However, the uniformity of the CMB does indicate a high level of homogeneity in the early universe, which is a key prediction of the Big Bang theory.

On the other hand, fluctuations in mass or temperature are not evidence for the CMB radiation being a remnant of the Big Bang. These fluctuations are known as anisotropies, and they arise from the density variations in the early universe. The measured anisotropies in the CMB have provided important insights into the formation of large-scale structures such as galaxies and galaxy clusters, but they do not directly support the Big Bang theory on their own.