Defining the Universe
The Universe encompasses everything that exists, has existed, and will exist, including all of space and time, and all matter and energy within it. It's the totality of existence, from the smallest subatomic particles to the largest galaxy superclusters.
Composition and Scale
Our Universe is predominantly composed of dark energy (about 68%), dark matter (about 27%), and ordinary matter (about 5%). Ordinary matter makes up everything we can directly observe, such as galaxies, stars, planets, and gas clouds. These components are spread across immense cosmic distances.
A Glimpse into its Vastness
To illustrate its scale, consider that our solar system, with its planets orbiting the Sun, is just a tiny part of the Milky Way galaxy. The Milky Way, in turn, is one of billions of galaxies estimated to exist within the observable Universe, each containing hundreds of billions of stars.
Studying the Cosmos
The study of the Universe's origin, evolution, and large-scale structure is called cosmology. Scientists use observational tools like telescopes and theoretical frameworks, such as the Big Bang theory, to piece together its history and predict its future, constantly refining our understanding of this grand cosmic entity.