The Big Bang Model

One of the most intruiging qustions in science has always dealt with the origin of our universe. The prominent thoery addressing this issue, the Big Bang Theory, assumes that the universe has been constantly expanding from a very hot, dense state to the cooler, less dense universe we live in today.

As the universe expanded after the Big Bang, particles such as quarks and photons emerged. Eventually it was cool enough for atoms to form. Gravity pulled matter together to make stars and galaxies. It is thought that although the universe was always expanding, gravity slowed that expansion over time.

But this isn't the whole story!