Water and air are akin to space. To the naked eye we can not see the individual constituents we only see and free the affects. Space, however at the subatomic level is not composed of atoms but is a constituent in and of itself. There can be no smaller constituent everything is composed of space and is differentiated only by vibration such as a bubble in a boiling pot of water.
Each and every particle of the universe is simply the vibration of space which gives rise to everything else. Therefore it was not a big bang but the first vibration or symphony.
The most interesting question is how did space begin to vibrate when it was presumably in equilibrium with no physical attributes to react to a universal sound (does a falling tree make a sound if there is no one there to hear it?) which was not in existence assuming that we are correct that nothing really exists outside of the physical universe we seem to occupy.
How can something which is not something vibrate? For example there is no sound in space that we can hear. It does however conduct electronic signals and light. Is space truly a vacuum or a medium we cannot perceive. Did prehistoric man realize the significance of air? The space time continuum simply can not be succinct defined be cause no one knows what space is.