I struggled with this--then I realized the question is flawed. The question presumes the default is <i>nothing</i>.<p>What if the default is <i>everything</i>?<p>In other words, there's no reason for the universe to be any one thing, including "nothing" so it is simply everything--every possibility that could be, is. Every combination of matter, every type of rules, or sequence of possibilities that can be, exists, all in infinite quantities. We just happen to exist in one possibility with conscious matter able to observe our small corner of the infinity of possibilities.
We are trying to answer this question with our minds, so how we think about the question and if it can be answered will depend on how we think about our minds.<p>If you take the scientific position that are mental processes are the produce of material brains produced through natural forces, you will believe our thinking is limited in power, like anything material. And that being the case, at some point the mind will run into questions it cannot answer, and the question of why there is something rather than nothing would seem to be that sort of question. And if you think of the problem that way then you will just accept the mystery and go on to thinking about matters where your mind might make some useful progress.<p>If you think our minds are the product of a God that understands everything, but made human minds limited, then you will also accept the mystery.<p>On the other hand, if you hold, as in Platonism or Hindu mysticism, that the mind is non-material and one with the Infinite, then you will likely believe that humans who grow spiritually enough can at some point come to understand why reality exists.<p>I think the waitbutwhy guy is philosophically in the first position but hasn't thought it out logically yet.
Marvin Minsky had an interesting take on this. His attitude was that ours is one possible world, but that possibility is all it takes. Imagine a computer program. It executes, it processes data and it produces output, but running the program doesn’t change the fact of its existence, or its result. Given that program and input the output was always going to happen, simply instantiating it didn’t change anything about the program or it’s behaviour. So with any universe, a possible universe simply exists.<p>Personally I find the zero energy universe concept pretty interesting. It turns out that the net energy of the universe is probably zero. This is possible because gravitational energy in the curvature of space is negative. If this is true, and it seems it is, then in terms of quantum mechanics there’s nothing to stop the universe from emerging from a net zero energy random fluctuation. But then a fluctuation of what? Well quantum fields are simply probability distributions. Maybe everything in the universe simply boils down to the possibilities expressed in a set of consistent probabilistic mathematical structures.
As it says in the article, it’s <i>the</i> question. But a clue is that to even ponder the question, there has to be something. If there really was <i>nothing</i>, you wouldn’t have noticed.