Special theory of relativity

It can be shown in some indirect way that the net energy of the universe is zero. For this, we will have to first determine as to whether the universe has a beginning in the past, or whether it has an eternal past. I think that there is a consensus among scientists that the universe is not past-eternal, but that it originated from a big bang 13.8 billion years ago. So we can say now that the universe has a beginning. Now there are only two options that can be taken into consideration while discussing the beginning of the universe. We can ask: 1) did it originate from nothing?