All matter and energy, including the earth, the galaxies, and the contents of intergalactic space, regarded as a whole. (noun)
The earth together with all its inhabitants and created things. (noun)
The human race. (noun)
The sphere or realm in which something exists or takes place. (noun)
Logic See universe of discourse. (noun)
Statistics See population. (noun)
Examples of word universe
Thus if the spherical-surface beings are living on a planet of which the solar system occupies only a negligibly small part of the spherical universe, they have no means of determining whether they are living in a finite or in an infinite universe, because the piece of universe to which they have access is in both cases practically plane, or Euclidean.
Specifically the notion that what we call our universe is a 4-dimensional space-time that itself is just a surface in a higher dimensional space, called a brane, a 4-brane in this case.
"The term universe in its complete physical sense applies to all matter in existence."
The word universe literally means everything that exists.
Since the universe is virtually transparent to radiation of these wavelengths, nothing would really have happened to it: the radiation would expand in universe at the same rate as the universe is expanding.