There are many different possibilities of how our universe began. Sir Isaac Newton said "The Earth is like a perfect machine". We really need knowledge that we don't have to find out how the universe began. Even though this obstacle stands in our way, scientists can still make hypotheses of how the universe started.
The most commonly used hypothesis is the Big Bang. Particles have been in space long before the Big Bang. There was too much that happened in the first second of time to be able to form a theory. What we do know about the first second is that the heat was so strong the galaxies were only made up of soups of quarks. When the earth was one-hundred seconds old protons and neutrons started to cling together because of cooling. There are still many things we don't know about the creation of the universe. This can also be called a super unified theory. .
Some disagree with the theory of the Big Bang. The French believed that God created the universe. In the 14th century France spent more money on cathedrals than the U.S. spent on sending a man to the moon! There are also people that disagree with the theory of God Creating the universe such a Einstein. He stated that, "God is simple but not malicious. .
Another theory was that the universe could have begun in a state of perfect symmetry. This theory was proven to be wrong because the Universe we live in is broken symmetry. It is true because there are objects in space and these objects break up symmetry. Even though this theory was incorrect, we may live in symmetry of broken crystallized symmetry's.
Aristotle stated that there are two basic forces in the universe. His statement was partly correct. This is true because there are really four forces in the universe. Though we have only found two forces, one including an electro weak force, scientists are still trying to find the two unknown forces. .
As you can tell we are not sure of how the universe began.