In Philosophy there is a standard called The Principle of Sufficient Reason.  Fundamentally this principle relies on the belief (or somewhat logical trust) that there is a coherent reason for everything… all the way up and all the way down, so to speak.  It suggests that for every circumstance there is a reason why it happened... there is a cause.  Parallel to this principle is the notion, “ex nihilo nihil fit” ("No thing can come from Nothing").  These two ideas are commonly considered to be true A priori, meaning, they are known to be true independent of experience.  If true, they essentially deny the possibility that Something could spring from Nothing, and that for every Something there is an explanation as to how it came to be like it is.  And, since we are obviously engulfed with a great deal of Something, there has always been Something.  One can argue for or against this principle, but even if it is accepted, a question arises whether or not this principle must be confined within some logical domain.  For instance, if you believe that God is the creator of all things, can you make this principle apply to Him?  Can you logically ask the classical, childlike question, “If God created everything, who or what created God?”  It seems to me that regardless of whether one believes in God or not, we are logically forced to reach a limit for the domain of The Principle of Sufficient Reason when it comes to the question, “Why is there Something, rather than Nothing?”.  This appears to be an unanswerable question, not because it is so difficult to determine, but rather because it is in and of itself a paradox.  And while it appears to be a question, semantically, it is, in fact, a puzzle with no valid solution.  Having said that, it is, I feel, a marvelous puzzle.

The mind is forever hungry for something; it might say to you, "give me something" (to do, see, think about). 

Our deep and eternal Nothing...bores the mind. 

Nothing is far more wonderful than something can ever hope to be, but the mind's desire requires a bit of "taming"!

Even though a complete and accurate answer is impossible to comprehend, the question is a good one.  It is more of a statement than a question.  And it leads an inquisitive mind into new areas of comprehension.

Galileo, in his day, surprised real thinkers with his astronomical description of orbits.  But he did not revolutionize the way we actually think.  He helped to move us away from the center of the Universe, but did not really offer us new ways of comprehending reality itself.  Newton and Einstein did that.  Newton got us to look under our skin and into the ethers, where he described gravity as omnipresent, instantaneous, and beyond spatial limitation.  Einstein then took the squared up world of Euclid and Newton and bent it into a neo-amorphous equivalency of mass and energy.  It became "neo-amorphous" in that there is structure, even architecture, at work in space and time, but not in the rigid sort of way that provides a snug place we can call "home."
  These thinkers dealt with the question of FORM.  What shape does it assume?  How will shape morph over time?  Even such questions as: "What is the shape of time?"  The question, "Why is there something, rather than nothing?" provided the fuel to tackle reality's structure, yet it remained and remains unresolved.  Fuel cannot be explained.  It simply burns.
  This question leads us to appreciate Plato's Allegory of the Cave.  We no longer just sense that we are watching shadows on the wall of the cave, we are absolutely certain of it... once we have the good sense to drop our parochial and prejudicial way of looking at reality.

  The question separates the pomp from circumstance, annihilates it, and leaves us both more empty and more vital.  Hence I thank you for asking the question.  I will leave you with a few questions of my own:
1) Is reality simulated?
2) Is reality bounded or unbounded?
3) Have we imagined the quantum world, or vice versa?
4) Are we a single Being with faceted consciousness, or are we discrete beings with localized consciousness?
5) Does the universe arise from an urge to oppose?
6) If my head remains too fixed in the clouds, will I drive my chariot over a cliff?
 
 
 

What makes you so sure there isn't nothing?

Well, if there is nothing (Nothing), then what are you doing there?

Otherwise we all would have missed the opportunity to watch Meryl Streep.

Because if there weren't, the question would hold no interest.

If there was nothing, you'd still be complaining.

You could always pinch yourself to be a little more certain that there is something, but then there is the question of who is pinching whom, if anyone or any thing at all.  Things that appear self-evident might well be illusory, or contain some unrecognized conceptual flaw.  In any event, the following might provide you with some lingering, poetic doubt (thanks to Steve Windwood):
http://www.youtube.com/watch?v=eoSn2Y-b6wI
 
 
 
 
 

  Nothing doesn't exist,
  Can only exist as Something
  Nothing can never be nothing
  Something is always something, true to its name.

My daughter was recently given a box, handed to her by a neighbor girl with Down Syndrome.  The possibilities of what might be in the box seemed endless.  Then she opened it, surprised that it was empty.  It made her laugh, thinking something was inside, yet found nothing.  She has kept the box.  Why?  Because she found humor in nothing, which made the nothing, something.

A monk asked Zen Master Joshu (Chao-Chou) “What is the depth of the deep?”
The master said, “How long has there been a ‘deep’?”
The monk said, “The deep has been here for ever.”
The master said, “Fortunately, you met me; you almost became someone who was ‘deeped’ to death.”