What is Reality?
The Universe is commonly defined as the totality of existence, including planets, stars, galaxies, the contents of intergalactic space, the smallest subatomic particles, and all matter and energy. Similar terms include the cosmos, the world, reality, and nature. The observable universe is about 46 billion light years in radius. Scientific observation of the Universe has led to inferences of its earlier stages. These observations suggest that the Universe has been governed by the same physical laws and constants throughout most of its extent and history. The Big Bang theory is the prevailing cosmological model that describes the early development of the Universe, which is calculated to have begun 13.798 ± 0.037 billion years ago. Observations of a supernovae have shown that the Universe is expanding at an accelerating rate. There are many competing theories about the ultimate fate of the universe. Universe
Solipsism ( i/ˈsɒlɨpsɪzəm/; from Latin solus, meaning "alone", and ipse, meaning "self") is the philosophical idea that only one's own mind is sure to exist.
Philosophers, mathematicians, and other ancient and modern thinkers, such as Aristotle, Plato, Frege, Wittgenstein, and Russell, have made a distinction between thought corresponding to reality, coherent abstractions (thoughts of things that are imaginable but not real), and that which cannot even be rationally thought. By contrast existence is often restricted solely to that which has physical existence or has a direct basis in it in the way that thoughts do in the brain. Reality is often contrasted with what is imaginary, delusional, (only) in the mind, dreams, what is false, what is fictional, or what is abstract.