The Big Bang is no longer considered just a theory; it is widely accepted as the prevailing scientific explanation for the origin and early development of the universe. The Big Bang theory proposes that the universe began as a hot, dense, and extremely small singularity approximately 13.8 billion years ago, and it has been expanding and evolving ever since.
The theory is supported by a wealth of observational evidence from various fields of astrophysics and cosmology, including the observed redshift of distant galaxies, the cosmic microwave background radiation, the abundance of light elements, and the large-scale structure of the universe. These pieces of evidence strongly support the idea that the universe was once in a highly compressed state and has been expanding over time.
While there are still open questions and ongoing research related to the precise details and mechanisms of the early universe, the overall framework of the Big Bang theory is well-established and has withstood extensive testing and scrutiny over several decades. It is considered one of the most successful and widely accepted scientific theories in cosmology.