The Big Bang theory is a widely accepted scientific explanation for the origin and evolution of the universe. It is supported by extensive observational evidence and theoretical frameworks. While there isn't a specific list of statements that constitute the "current version" of the Big Bang theory, I can provide you with a summary of the key ideas and observations that underpin the theory:
The universe had a definite beginning: The Big Bang theory proposes that the universe originated from an extremely hot and dense state around 13.8 billion years ago. This is supported by observations like the cosmic microwave background radiation, which is considered the remnant heat from the early universe.
Expansion of the universe: Observations of distant galaxies and their redshifts indicate that the universe is expanding. The galaxies are moving away from us, suggesting that the universe was once much denser and smaller.
Hubble's Law: The observation that the velocity at which galaxies are receding from us is directly proportional to their distance is described by Hubble's Law. This provides further evidence for the expansion of the universe.
Primordial nucleosynthesis: The Big Bang theory explains the abundance of light elements like hydrogen and helium in the universe through a process called primordial nucleosynthesis. It predicts the ratios of these elements, which match observations.
Cosmic microwave background radiation (CMB): The CMB is a pervasive, isotropic radiation that fills the universe. It is considered one of the strongest pieces of evidence for the Big Bang. The observed pattern and characteristics of the CMB support the theory's predictions.
Large-scale structure formation: The Big Bang theory explains the formation of galaxies and large-scale structures in the universe. Small density fluctuations in the early universe expanded over time, leading to the formation of galaxies, galaxy clusters, and cosmic filaments.
Cosmic inflation: The theory of cosmic inflation proposes that the universe underwent a brief period of extremely rapid expansion in its early stages. This helps explain the observed uniformity of the universe on large scales and other aspects of its structure.
These are some of the fundamental concepts and observational evidence supporting the Big Bang theory. It's important to note that scientific theories are continually refined and updated as new evidence emerges, so the specific details and understanding of the theory may evolve over time.