The observable universe is a spherical region of the Universe comprising all matter that can be observed from Earth at the present time, because electromagnetic radiation from these objects has had time to reach Earth since the beginning of the cosmological expansion. There are at least 2 trillion galaxies in the observable universe. [1] I have the observable universe as @My Background on my iPhone as an ever present prompt of perspective; maintaining some element of @Optimistic Nihilism throughout the day. ::embed[https://www.youtube.com/embed/Han7bc1Os4A]{provider=youtube}
References
- Observable Universe, wikipedia.org
- What is The Universe and Observable Universe, youtube.com