The Big Bang theory is currently the standard theory taught to explain the origins of the Universe. This theory however is lacking in certain ways, such as describing the quantum mechanical effects at the time involved and where the Big Bang came from. A variation of the Big Bang theory called the Big Bounce theory however does answer these questions as researchers at Penn State have revealed.
Instead of being based on General Relativity, the Big Bounce theory uses a quantum theory of gravity and considers the quantum-mechanical geometry of space-time. According to it, the object that exploded in the Big Bounce was an ultra-dense mass at roughly 1094 grams per cubic centimeter (an atomic nucleus is roughly 1014 grams per cubic centimeter). Due to that extreme density, there were many odd quantum-mechanical behaviors going on inside of it, and the fluctuations involved may have resulted in fluctuations we can see today. When the researchers modeled what the quantum fluctuations would due as the mass inflated after the bounce, they found they would evolve into the spots we can see in the cosmic background radiation. These spots then act as seeds for the galaxy clusters of the modern-day Universe.
This is a very important step towards understanding the origin of the Universe as it goes back to the very beginning, unlike the Big Bang theory which stops at the inflationary period of rapid expansion. Perhaps one day the questions concerning the events prior to the Big Bounce will also be answered.