The big bang was that point from which the universe started to exist, releasing a huge amount of <u>Cosmic Microwave Background Radiations (CMBR) into the space</u>.
<u>CMBR is an electromagnetic radiation that are the the oldest remains of the big bang explosion</u>. With the continuous expansion of the universe after the explosion, this radiations ere constantly spreading in all the direction for the last 13.5 billion years approximately.
