Nature of the Universe

The universe is all of space, time, matter, and energy that exists. It includes galaxies, stars, planets, and even the emptiness between them. The universe began about 13.8 billion years ago with the Big Bang, a rapid expansion from a hot, dense state. It is constantly expanding, meaning galaxies are moving away from each other. Laws of physics govern its behavior, shaping the formation of celestial bodies and cosmic structures. Despite extensive knowledge, many mysteries remain, such as the nature of dark matter and dark energy, which make up most of the universe's mass-energy but remain largely unknown.