The below is explained by Rebbe Nachman in Likutey Moharan #64:1 (based on the Etz Chaim by the Arizal). It describes how a contraction (tzimtzum) from the infinite (Ein Sof, without end) light of God, blessed be his name, is the source of the creation of our world.
I think this is consistent with the theory of the "Big Bang." Consider, for a moment, that there is Ein Sof. That is, I am suggesting that the fundamental nature of the universe is infinite energy. God is infinite. Endless. Without end. Pure light, energy. And even if you don't have faith that this is God, then simply accept for the momemnt that the fundamental nature of the Universe is infinite energy, and call that what you want. But fundamentally, there is energy that is all one, alone, compeltely conected, and infinite in power and endless in light and heat.
Now, consider what would happen if this endless infinite light were to contract away from itself, leaving a void. Perhaps leaving a portion of its infiniteness behind in the center of that void. A portion of energy equal to the energy contained in the world that we know.
As the infinite contracted away from the finite energy left behind, perhaps what then occured was the Big Bang, as the gravity and pull of the infinite away from what was finitely left behind caused the finite to rapidly expand out towards the infinite. And as that occurred, the light became strings of matter, and eventually these gathered into atoms and created space, and created time, that make up our physical world.
Wouldn't this explain why the Universe that we see is expanding outward? Because it is returning to the infinite. It is returning to Him.
