13.8 billion years ago, the Big Bang initiated and that left an aftermath, cosmic background radiation (CBR). Through the trace of this CBR, scientists confirmed the time of the Big Bang. This radiation is travelling at the speed of light after its creation. Now today, the 20th April, 2018, midnight Asia Pacific time, this radiation will cross our Earth. Because, it took 13.8 billion years to travel at the speed of light to cover the distance to reach our Earth from the point of its creation. This proves that our Universe is so infinitely big, that it is really unimaginable by a human being. That is, what we call space is infinite in size and no one knows where are its boundaries or edges.