Important Notice: Our web hosting provider recently started charging us for additional visits, which was unexpected. In response, we're seeking donations. Depending on the situation, we may explore different monetization options for our Community and Expert Contributors. It's crucial to provide more returns for their expertise and offer more Expert Validated Answers or AI Validated Answers. Learn more about our hosting issue here.
A. Astronomers believe that the universe began in a “big bang”, about 15 billion years ago, and that this produced the expansion. The universe expanded from a state of very high density and temperature. The “big bang theory” is supported by several pieces of evidence; astronomers can observe the radiation and the chemical elements which were created in the “big bang”.
