null, -null-, or ∅ is the representation of having the absence of something, or it not existing. When things like the Blueprint Particle didn't have size, and · didn't have dimensionality. It was never even questioned until what exactly an object having no property actually meant. This is null.
null, being a semi-physical object, can be thought of as being split into two 'halves'; the physical part, called null, and the abstract/numerical part, called ∅. The full object is called null or sometimes -null- to differ it from its physical part.
Physical section: null
null is the physical (albeit smaller) half of null. It is similar to Nothing. null is absence itself, but Nothing is the absence of anything at all.
null cannot be viewed or measured, sort of like trying to measure the color of a hole; you can figure it out for everything around the hole, but the hole itself cannot be measured. null is similar, just that these 'holes' can be found in any property of an object, if you look deep enough.
Abstract section: ∅
The abstract section of -null-, called '∅' and pronounced 'null' is very similar to the null set, something that does not contain any objects. ∅ is the abstract name for there not being a number, value, function, symbol, etc. It can be thought as the 0 to the Numbars, as Mathons and other kinds of Numbars build up from ∅ to create all the other concepts. It fills in the missing spaces in our logic.