Unit 5: Explain a piece of evidence that supports the Big Bang Theory.
One piece of evidence that supports the Big Bang Theory is the observed cosmic microwave background radiation (CMBR). In the 1960s, astronomers Arno Penzias and Robert Wilson discovered a faint background radiation that was uniformly distributed across the entire sky. This radiation, known as the CMBR, is a low-energy electromagnetic radiation that exists in the microwave spectrum.
The key significance of the CMBR is that it supports the idea that the universe had a hot, dense, and expanding beginning. According to the Big Bang Theory, approximately 13.8 billion years ago, all matter and energy in the universe were compressed into an extremely hot and dense state. As the universe rapidly expanded, it began to cool down.
As the universe cooled down, about 380,000 years after the Big Bang, protons and electrons combined to form neutral hydrogen atoms. This process, known as recombination, resulted in the release of energy in the form of light. Initially, this light would have been in the form of high-energy photons, but as the universe expanded further, these photons stretched and cooled, eventually becoming the CMBR that we detect today.
The existence and characteristics of the CMBR provide strong support for the Big Bang Theory. Its uniform distribution across the sky corresponds with the idea that the universe expanded from a single point, as predicted by the theory. Moreover, the CMBR acts as a relic of the early universe, providing an indirect snapshot of the conditions and events that occurred shortly after the Big Bang.
Detailed measurements of the CMBR, such as its temperature fluctuations and polarization patterns, have provided further evidence supporting the Big Bang Theory. These measurements align with the predictions made by cosmological models that assume an expanding and evolving universe.
Overall, the discovery and observation of the cosmic microwave background radiation, with its uniform distribution and characteristics, constitute a significant piece of evidence supporting the Big Bang Theory and the understanding of the early universe.