How does weak background radiation coming from every direction in the sky support the Big Bang Theory?
Weak background radiation coming from every direction in the sky, known as the cosmic microwave background (CMB), strongly supports the Big Bang Theory. Here's why:
1. Predicted by the theory: The Big Bang Theory predicts that the universe originated from an extremely hot and dense state around 13.8 billion years ago. As the universe expanded, it also cooled down. According to the theory, this cooling process led to the release of radiation in the form of CMB. The discovery of CMB in 1965 by Arno Penzias and Robert Wilson provided strong evidence confirming the predictions of the Big Bang Theory.
2. Uniformity: The CMB is extremely uniform, with almost the same temperature being observed in all directions of the sky. This uniformity supports the idea that our universe started from a highly compressed and homogeneous state. The fact that the radiation is evenly distributed supports the expansion and subsequent cooling of the universe.
3. Cosmic microwave background radiation temperature: Through precise measurements, scientists have determined that the temperature of the CMB is approximately 2.7 Kelvin (-270.45 degrees Celsius). This temperature corresponds to the current average temperature of the universe. The CMB temperature matches the predictions made by the Big Bang Theory, providing strong evidence in its favor.
4. Cosmic microwave background anisotropies: While the CMB is highly uniform, it does exhibit small temperature variations or anisotropies. These anisotropies represent tiny fluctuations in the density of matter present at the time of the CMB's emission. The observations of these anisotropies and their distribution patterns have been consistent with the predictions made by the Big Bang Theory and the subsequent formation of structures like galaxies and galaxy clusters.
Overall, the discovery and characteristics of the cosmic microwave background radiation align precisely with the predictions of the Big Bang Theory, lending strong support to the idea that the universe originated from a hot and dense state and has been expanding ever since.