The cosmic microwave background (CMB) is the faint afterglow of the Big Bang, which permeates the universe. It's a form of electromagnetic radiation that fills the entire universe and is a crucial piece of evidence supporting the Big Bang theory.
The cosmic microwave background (CMB) is the faint afterglow of the Big Bang, which permeates the universe. It's a form of electromagnetic radiation that fills the entire universe and is a crucial piece of evidence supporting the Big Bang theory.