Through a combination of astronomical observation and physics of fundamental particles and force laws under extreme conditions, we have a remarkably complete picture of how the Universe evolved in its early stages. This picture starts with the Big Bang and shows how the familiar particles and atoms formed from the original sea of extremely high energy matter. It explains more or less how the Universe eventually became lumpy and the lumps condensed into galaxies.

"The most incomprehensible thing about the Universe is that it is comprehensible." - Albert Einstein