Humans are imperfect. The laws of nature are perfect.
Or so we think.
At the moment of the big bang, the moment of creation, the universe exploded. The four fundimental forces of our universe were a "superforce", pushing the universe out in all directions. But if that were so, we would not exist.
At the moment of the big bang, the universe did not expand evenly in all directions. There were imperfections; chunks of the universe that traveled together, leaving empty space in other directions.
However, there is a theory of supersymmetry. It states that in the moments before the big bang, our universe was unified. All four forces, gravity, electromagnetism, and the two strong and weak nuclear forces, as well as matter and everything else in our universe were all one. It also says that over time, these forces and particles separated, in a very asymmetrical fashion, giving us the world we see today.
There is also another explination. It is string theory. Quantum physics is very sci-fi most of the time, and string theory is pretty much the empitome of science fiction sounding theories.
String theory compares our world to music. It says that all particles are strings. Gravity particles, atoms, light particles; they are all strings. The key, is that these strings have energy, and are constantly vibrating at different rates.
Did you catch that? The basis of string theory is that our world is still unified. It is assumed that everything, everything is all made up of the same thing: strings.
String theory says that our universe is all still unified.