The universe has echoes of its birth

universe

 Our universe was born about 13.7 billion years ago in a massive expansion from nothing to everything. There are thermal imprints present of the Big Bang. These imprints clarify that we don't see any object older than 13.7 billion years .

           

                            Here echo is not referred to the sound which was heard after the explosion in the creation of the universe. In this context echo is actually referred to the "cosmic background radiation", electromagnetic radiations from the Big Bang which are present now everywhere.

 

                      As the theory predicts early universe was a very hot place and with its expansion it is cooling down. When the universe was born it underwent an immense rapid inflation and expansion which released a radiation field, a field of extremely high temperature and pressure, beyond our imaginations. This leftover radiations and heat from the Big Bang is called Cosmic Microwave Background (CMB). You cant see CMB with your naked eyes because it is too cold (minus 273 degree celsius).

                         The universe began 13.7 billion years ago and the CMB dates back to about 400,000 years after the Big Bang. The reason behind is when the universe was in early stage, when it was just 1 hundred millionth the size it is today, its temperature was extreme, 273 million degree above absolute zero, according to NASA. Any atom present at that time would quickly break into small particles. The Cosmic Microwave Background radiation has a frequency of 160 GHz and wavelength of 1.9 mm.