One of the possible ways of thinking of the universe is to imagine it as a vast expression of a Divine thought - an idea, as it were, in the mind of God. A world that exists in the mind of God may make questions like why it exists, where do quantum particles go when they pop out of existence, how can a particle exist in two locations simultaneously, how can two photons traveling apart at the speed of light interact with each other, etc. somewhat easier to answer.
Now, however, comes another view the ontology of the universe. This idea, which has been around for a while but just recently received some experimental support, portrays the cosmos as a vast hologram. Just as light reflected off the surface of a credit card can produce an image of a three dimensional object, so too, according to this theory, could energy reflected off the surface of the universe's boundary produce the appearance of a three-dimensional world. This world doesn't really exist, or, more precisely, doesn't exist in the solid, material way we think it does, rather it's a pattern consisting of extremely tiny pixels.
It's a very strange theory and, truth to tell, I prefer the mind of God theory, but who knows? I'm quite sure that reality, the really real, is not at all the way we imagine it to be. I have little doubt that the world of our everyday experience is a consequence of our being the size we are, having the particular senses we have - with the particular constraints they impose - and having a mind which, in addition to other limitations, is only able to conceptualize in three dimensions. Were we the size of atoms or galaxies, were we to have six or more senses or were the senses we have able to perceive stimuli over a wider range, or were our minds more expansive than they are, our experience and understanding of the world might be entirely different than what it is.
Just as a man born blind and deaf has a very attenuated concept of what the world is like, unable as he is to imagine blue or music, for instance, so we have a very limited concept of reality because the structure of our senses and minds prohibits us from experiencing its full richness and reality.
We are like an unborn child trying to imagine the world outside its mother's womb. It's not long before we run smack up against the limits imposed by the structure of our minds and bodies.RLC