In three to five sentences, evaluate the scientific evidence that supports the big bang theory and the steady state theory.
To evaluate the scientific evidence supporting the Big Bang theory and the Steady State theory, we need to look at various lines of evidence. The Big Bang theory is supported by several observations, such as the cosmic microwave background radiation, the abundance of light elements in the universe, and the redshift of galaxies. These pieces of evidence align with the idea that the universe originated from a hot, dense state and has been expanding ever since. On the other hand, the Steady State theory, which proposes that the universe is eternal and unchanging, lacks substantial evidence and has been largely discredited due to observations showing the overall evolution and changing nature of the universe.
To delve deeper into the evidence supporting the Big Bang theory, the discovery of cosmic microwave background radiation in 1965 provided a crucial piece of evidence. This radiation, detected uniformly in all directions, is a remnant of the hot, dense early universe and supports the idea that the universe was once highly compact and energetic. Additionally, the observed abundance of light elements, such as hydrogen and helium, is consistent with the predicted ratios from the conditions present during the early universe.
Further evidence comes from the observation of the redshift of galaxies. Edwin Hubble's discovery in the 1920s that galaxies are moving away from us, with more distant galaxies displaying greater redshift, suggests that the universe is expanding. The rate of expansion has also been measured, providing additional support for the Big Bang theory.
In contrast, the Steady State theory postulated a constant creation of matter to maintain a steady universe. However, this theory struggles to explain several observations, such as the cosmic microwave background radiation, the absence of older galaxies, and the overall evolution of galaxies and cluster formations. As a result, the majority of the scientific community now supports the Big Bang theory, which is backed by numerous lines of observational evidence.