It seems that some of the new "free lunch" cosmological models promote the idea that if the universe has zero net energy, zero energy was required to create it. However, a closed system can have tremendous potential energy but zero net energy, so the idea seems questionable to me, even if the positive and negative energies add up to precisely zero. For instance one unit of positive energy plus one unit of negative energy equals zero net energy, but a potential energy difference of two units. It does not seem as though the expansion of space could create energy from nothing, either. Otherwise, how could the matter separated by inflation have had kinetic or gravitational potential energy without the law of the conservation of energy being violated? So what do you think? Am I on track in thinking that the creation of the universe probably required energy, such as a powerful quantum fluctuation of tremendous energy, as Tyron assumed with his original proposal, or off base here? if I am off base, please try to explain it to me in simple terms that a non-scientist like me can understand.