Universe began with Big Bang from "summary" of A Brief History of Time by Stephen W. Hawking
According to the Big Bang theory, the universe began as a singularity – a point of infinite density and temperature – about 13.8 billion years ago. At this moment, all the matter and energy in the universe was concentrated at a single point, with gravity so strong that not even light could escape. This singularity then began to expand rapidly, creating space and time as it did so. As the universe expanded, it cooled down and matter began to form. This matter eventually coalesced into galaxies, stars, and planets, creating the vast cosmos that we see today. The expansion of the universe is still ongoing, with galaxies moving away from each other at incredible speeds. The Big Bang theory is supported by a wealth of observational evidence, such as the cosmic microwave background radiation – a faint glow of radio waves left over from the early universe – and the large-scale structure of the cosmos. In addition, the theory accurately predicts the relative abundances of the light elements, such as hydrogen and helium, which were formed in the first few minutes after the Big Bang. While the Big Bang theory has been incredibly successful in explaining the origins and evolution of the universe, there are still many unanswered questions. For example, what caused the Big Bang in the first place? What happened in the moments immediately following the initial expansion? And what is the ultimate fate of the universe? Scientists continue to explore these mysteries in the hope of gaining a deeper understanding of the cosmos.- The concept of the universe beginning with the Big Bang is a cornerstone of modern cosmology. It provides a framework for understanding the origins and evolution of the cosmos, and has been supported by a wealth of observational evidence. Despite the unanswered questions that remain, the Big Bang theory represents a major milestone in our quest to unravel the mysteries of the universe.
