Nothingness Is a Perfect. It is an experience where no matter how Mind examines, rotates, or transforms an experience, the experience is exactly the same. The interesting thing about a perfect symmetry is that while Mind perceives it as Nothing, it is still Something. It is ONE thing. Many others thinkers in response to this question have stated as such. So Nothing is the purest Existence object of Mind. If Mind could describe say the colour of Nothing it would answer that it is ALL Black, or ALL White, or ALL Blue, …, to Infinity. In this way Nothingness is also the ALL. Any particular colour (or category of description) can be expressed by Mind. As long as it is perfectly symmetrical it will be described first as ONE thing; and then as Nothing else; and then as Everything. So Nothing is the (O)NE, the (N)ONE and the (E)VERY. The ONE.
“Whether we scientists are inspired, bored, or infuriated by philosophy, all our theorising and experimentation depends on particular philosophical background assumptions. This hidden influence is an acute embarrassment to many researchers, and it is therefore not often acknowledged. Such fundamental notions as reality, space, time and causality – notions found at the core of the scientific enterprise – all rely on particular metaphysical assumptions about the world.”
— Christof Koch, Neuroscientist