INSIGHT
The Cosmic Background Radiation is a radiation that prevents us from looking beyond it. It originated 380,000 years after the Big Bang (on the other hand, thanks to it, we can observe the young Universe). 380,000 years is nothing compared to the life of the Universe: yet almost everything happened in those years, or better, in the first moments. It also constitutes 1% of every frequency disturbance we experience on Earth, even the radio ones: when your radio crackles, you are, in part, listening to the Big Bang.
The Cosmic Background Radiation proves the Universe is neither infinite nor eternal, also because otherwise the night sky would be completely illuminated by the light coming from the infinite stars in the Universe: instead, they are scattered on a canvas completely dark to our eyes, actually much more varied to the sensors of antennas.
The Universe 380,000 years after the Big Bang
Why can’t we see beyond this background radiation? Is it perhaps because it covers our sight? No, we can't see beyond it because there was nothing to see before it or at least nothing in the form of visible light. It is said the Universe was opaque, but you can take a better look at this notion in the next pages.
PIC CREDITS
WMAP map of cosmic microwave background anisotropy, from the mission's Data Release 1 - NASA/Goddard/WMAP Science Team