DAVID A. HARDY / SCIENCE PHOTO LIBRARY DAVID A. HARDY / SCIENCE PHOTO LIBRARY
Expanding universe. Illustration of galaxies expanding from the Big Bang. The Big Bang is a theory of the formation of the universe, in which the universe is still expanding from an infinitely dense point which existed about 15 billion years ago. Galaxies moving away from Earth display red shift (as seen in upper frame), as their light is shifted towards the red end of the spectrum by their motion.
Model release not required. Property release not required.