The Universe is comprised of many galaxies and it appears to be expanding. This implies that there was a beginning, called the Big Bang.
The Universe is comprised of many galaxies and it appears to be expanding. This implies that there was a beginning, called the Big Bang.
During the 20th Century, many great leaps were made in the science of astronomy. Possibly the most important were the observations of the astronomer Edwin Hubble, which reinforced the notion from Einstein’s Theory of Relativity that the Universe could not be a static shape. His observations were that all stars in different galaxies other than the Milky Way (our own galaxy) had a red shift, implying that they were moving away from us.
To reinforce this theory of an expanding Universe cosmologists (scientists who study the physical and theoretical nature of the Universe) predicted there would be an electromagnetic radiation (cosmic wave background radiation) as a lasting trace of the explosion, which was first detected in 1965.
The amount of the lighter elements apparent in the Universe (hydrogen and it’s isotopes, helium, lithium and beryllium) are also considered consistent with that predicted by Big Bang Theory.