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?