Did the universe originate from nothing?

In 2010, scientist Lawrence M. Krauss wrote an article1 in the Wall Street Journal in which he argued that since the total amount of energy in our current universe is zero, it follows that the universe originated from nothing. The gist of his argument was this: Let us assume that the universe actually arose from nothing. (Here it is the so-called nothing of scientists, not the nothing of philosophers.) Then the total energy of the universe must be zero, because everything here started from nothing. Amazingly, scientists have also found that the total energy in the present universe is zero. So it is natural to say that the universe actually originated from nothing, because only then would its total energy be expected to be zero.

But by applying the same argument that Krauss uses for showing that the universe originated from nothing, it can be shown that the universe could not have originated from nothing. His argument was this: If the universe had originated from nothing, then the total energy of the universe would be zero. And the total energy of the universe is also zero. But if the total energy of the universe is zero because of the fact that the universe had originated from nothing, then the total amount of space-time of the universe will also be zero because of the same fact that the universe had originated from nothing, But have scientists been able to show that the total amount of space-time in the universe is zero? If they can't show it, then they can't claim that the universe had originated from nothing.

Reference:
1. http://www.wsj.com/articles/SB10001424052748703946504575469653720549936