5 days agoThe “observable universe” is the region of space that humans can actually or theoretically observe with the aid of technology.The cosmological expansionFinite or infinite?The Einstein–de Sitter universe
Cosmology is a branch of physics and metaphysics dealing with the nature of the universe. The term cosmology was first used in English in 1656 in Thomas Blount's Glossographia, and in 1731 taken up in Latin by German philosopher Christian Wolff,
WikipediaBooks CosmologyA Brief History of Time
The Little Book of Cosmology
The Elegant Universe
The Big Picture: On the Origins of Life, Meaning, and the Universe Itself
Until the End of Time
The First Three Minutes: A Modern View of the Origin of the Universe
Fast Facts
The oldest light that reaches the Earth is 13.77 billion years old. The universe's total energy budget consists of approximately 5 percent regular matter, 27 percent dark matter (which interacts with ordinary matter via gravity but does not interact with light), and 68 percent dark energy.