Giant levitating superturtles

I'm a big fan of Dr. Michio Kaku, the theoretical physicist who specializes in String Theory. Today on his blog he answered a question from a reader that echoes some common confusion about Stephen Hawking's latest book, The Grand Design: "Can a universe create itself out of nothing?"

Dr. Kaku essentially explains that because the total energy of the universe is zero, it does not require a net positive increase in energy to create a universe. This is similar to the explanations I've heard from Lawrence Krauss and Stephen Hawking himself. But I feel like it's probably a bit of an unsatisfying answer for many, because when these physicists are using the word "nothing", they're not really using it the way most people use it colloquially. We generally think of "nothing" to mean absolutely nothing at all – no energy, no matter, no physical laws, no universe – you know, nothing. These physicists are using it in a sense of no matter, and suggesting that the forces of nature are already there. But then, aren't those forces what makes the universe? Where did those come from?

There's an old Hindu myth that says that the world rests on the back of a turtle. Bertrand Russell mentioned it in his lecture Why I Am Not A Christian:

If everything must have a cause, then God must have a cause. If there can be anything without a cause, it may just as well be the world as God, so that there cannot be any validity in that argument. It is exactly of the same nature as the Hindu's view, that the world rested upon an elephant and the elephant rested upon a tortoise; and when they said, "How about the tortoise?" the Indian said, "Suppose we change the subject."

In other words, theists are supposing that God is the immovable, causeless turtle. But there's no particular reason to assume it ought to be God. It could be the thing that created God, or the thing that created the thing that created God (and on and on ad infinitum). Believers will of course avert the infinite regress by asserting that God, like the immovable turtle, simply is. Hawking (and Russell) is suggesting that the universe itself (or the multiverse, if you want to get complicated) is the immovable turtle – that thing that simply is. 

So there needs to be some distinction here. When Hawking is saying that the universe can create itself out of "nothing", he's really saying that the observable universe did not require a net positive energy to emerge, and that the fundamental constituents of the universe didn't have to come from anything. He ends chapter 8 of A Brief History of Time:

So long as the universe had a beginning, we could suppose it had a creator. But if the universe is really self-contained, having no boundary or edge, it would have neither beginning nor end: it would simply be. What place, then, for a creator?