What is the nature of the universe and its origin?
This description explores the nature of the universe and its origin. It examines the various theories and hypotheses that have been proposed to explain the universe's structure, composition, and evolution. It also looks at the evidence that has been gathered from astronomical observations and experiments to help us better understand the universe's
The universe comprises all of existence: all forms of matter and energy, and the structures they form, from sub-atomic particles to entire galactic filaments. Since the early 20th century, the field of cosmology has established that the universe has been expanding for 13.8 billion years, starting from a dense fireball in an event called the Big Bang. The observable portion of the universe is approximately 93 billion light-years in diameter at present. The total size of the universe is not known.