Cosmologists take our study of the past as far back as they can. There are limits to our knowledge however (more likely we just haven't figured out how to pass those limits yet). We can only travel so far back in time before everything we have learned about our universe no longer applies. This is what we call the "beginning." Not because nothing existed before that beginning, but rather because we have no way of describing it. Before our universe was created, space and time did not exist as we know it. If we were somehow able to peer past our beginnings, none of our laws of physics would even apply. It is unlikely that we would even be able to comprehend what we saw.

Perhaps we have the capability to understand what happened before the beginning and our knowledge just has not reached that point yet. Perhaps we shall never truly understand what happened before time was created. We can, however, travel back approximately 15 billion years (give or take five billion years or so), to where the universe was simply a point in space. This is where our journey begins, at a point in time now known as the Big Bang.

Fifteen billion years ago everything in our universe existed in singularity. A singularity is a point in space that is infinitely small but can have an extremely large amount of mass in it. It is unclear what happened next but something caused this singularity to explode, hurtling all the mass that was in it outward at an incredible rate. The energy from this explosion caused reactions in some of these particles, known as quarks, causing them to combine and form the first protons. Later, neutrons and electrons would form and start the basis for all of the elements that we know.