Universe. There are many competing theories about the ultimate fate of the universe.
Physicists remain unsure about what, if anything, preceded the Big Bang. Many refuse to speculate, doubting that any information from any such prior state could ever be accessible. There are various multiverse hypotheses, in which some physicists have suggested that the Universe might be one among many or even an infinite number of universes that likewise exist. Historical observation.
Solipsism. 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.
As an epistemological position, solipsism holds that knowledge of anything outside one's own mind is unsure. The external world and other minds cannot be known, and might not exist outside the mind. As a metaphysical position, solipsism goes further to the conclusion that the world and other minds do not exist. Varieties Reality. 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. Chaosbunny. On Truth & Reality: Philosophy Physics Metaphysics of Space, Wave Structure of Matter. Famous Science Art Quotes.