When we ask “Why is there something rather than nothing”, we are not necessarily asking the exactly the same thing as “Where did the universe come from?”, or “What caused the universe?”
The last two forms of the questions might, in a sense, be viewed as “physics questions”, whereas the first is a philosophical, or metaphysics, question. Consider this: it might conceivably be possible to someday show that the laws of physics of the vacuum imply that sometimes a universe can spontaneously form. For example, maybe it could be shown that a virtual process like the “vacuum bubbles” that inhabit and comprise the vacuum in quantum electrodynamics could sometimes happen on a grander scale and produce a universe out of something like a “Big Bang”. Once a complete theory of everything (a “TOE”) is arrived at, perhaps it will be evident that a vacuum state, governed by the laws of physics, is unstable, and must “explosively collapse” into a realm of matter and energy.
Today, one can find on the internet many examples of people postulating guzillions of parallel universes, maybe all with different laws of physics. Is it totally unreasonable to suppose that a set of meta-laws exists that can spontaneously determine the form the laws of physics can take in a newly emerging universe? Of course, I do not see at present how we could ever discover these meta-laws using our presently conceived form of the scientific method. Physics, as it is understood by scientists today, is empirically based. That is, it must be verified by observation and testing.
Physicist David Deutsch argues, in his book The Fabric of Reality that quantum theory, well accepted among physicists today and largely verified by experiment, implies that there are parallel universes, comprising the multiverse. But this does not really address why things exist (since these parallel universes just consist of more "things").
The point I want to make here is that when we ask the age old question “Why is There Something Instead of Nothing?” we are asking something quite different than the physics question, even recognizing that there may be meta-laws behind the physics laws of our particular universe. We are asking the fundamental existential question about existence itself. “Nothing”, in this sense, would be absolute nothingness: no laws, no possibility of virtual process, no anything, just a blank everywhere. It is inconceivable what this kind of nothing is, we do not even seems to have the words to describe it, we cannot imagine it, and yet the odd thing is that to those of us that ask the question and wonder at it, it seems somehow logical that that Nothing should be the “default” state of affairs.
Is this existential question a meaningful one? Well, it is not answerable by any conceivable method that we might think of. In fact, we cannot even think of what an answer to it might look like, partly because any explanation we might proffer for anything always uses concepts from a realm where there are things (i.e., there is something).
William James apparently studied, or pondered, the “Why is There Something Instead of Nothing?” question, and referred to the associated vertigo like emotional rush that occasionally comes to some of us as “Ontological Wonder Sickness” . A sort of pompous sounding name, perhaps. But it is, I suppose, rather like the psychological phenomena of “déjà vu”, rather unsettling and bizarre. According to logician and philosopher Martin Gardner the protagonist of Sartre’s novel Nausea experiences the emotion as being darkly disturbing and depressing. For others, such as me, it is not a bad feeling, but rather usually one of astonishment and wonder, intriguing and maybe even awe-inspiring.
Let me return to the issue of whether, intellectually speaking, the question is a meaningful one. I actually think it is, but that it is unanswerable. But just as Godel’s Proof says that there are mathematical and logical questions that cannot be decided (as being true or false), with a given logical system, it seems to me there are analogous metaphysical questions. There may be a reason why there is “something rather than nothing”, but we cannot know what it is. It is fundamentally unanswerable, not because of the accidental limitations of our human brains, but beyond the ken of any physical intelligent entity.
Of course, it is common to hear people say that “God” (or “gods”) is the reason why there is something rather than nothing. In spite of the absurdity illustrated by the “Turtles all the Way Down” story---basically, using God to explain the Universe just shifts the question to “Why is there a God rather than Nothing?”. But does it really, I sometimes wonder? If I understand quantum mechanics at all (and I readily admit I probably don’t, at least not very well) there is a hint that consciousness may be a more fundamental existent than any kind of “stuff”. There are many web sites that attempt to develop or put forward this idea. Unfortunately many of them seem to me to be in the rather kooky sphere, along the lines of the dubious film “What the Bleep do We Know” ; a google search on “the primacy of consciousness” turns up a great many sites that seem to me to be of the same type as that film (for example 1, 2, 3).
However, the late John Wheeler, without a doubt one of the greatest physicists of the 20th century, felt that consciousness, if not primary, at least plays a key role in the existence of the universe, and asked “Does the Universe Exist if We Are Not Looking?”
However, it seems to me that his explanation, or intuition, of why things exists is really an attempt at an answer of “Where did the universe come from?” rather than the metaphysical one of “Why is there something rather than nothing?”
The opposite view, that consciousness is not primary, and that things exist independent of our consciousness was propounded by philosopher Ayn Rand (4).
It is all quite confounding. But at this point, the plausibility of this “primacy of consciousness” idea is one of the reasons I deem myself an agnostic instead of an atheist. And I greatly enjoy contemplating “Why is there something rather than nothing”, even knowing that it is surely unanswerable.