Why is it that there is a North pole and a South pole on the Earth? We detect the North magnetic pole using a compass detector, there are four co-ordinate directions on a compass, North,South, East and West, but the detector only detects North. One can know where the North Pole is situated by the signal of the compass needle, at the equator, one cannot locate East or West, they are both just global convience directions, and can be ignored, WRT Earth's magnetic Field.
Now for the Graviton, one has surely to have a detector that can ignore the irrelevent "forces", all except Gravity, one really does need a force filter Graviton Detector?
Now I am certain that Graviton is a spin 2 particle, it's identiy is dual (helicity)?..this attribute I believe is functional to the properties of Gravity, it can be both positive (attraction) and sometimes negative (repulsion).
Spin of 360% equals one rotation in one 2-D direction, (left or right), whereas a 720% rotation can be seen as a "double" spin, or for 2-D field propergations, a full 360% rotation to the left, and a full 360% rotation to the right.
In 2-Dimensions the rotation can be oscillating say from left to right, and continues right to left. In a 3-Dimensional realm, this action results in a Vector rotation . Like the fact one can travel from North to South and continue to North (full rotation on the globe), one can also travel North-South-North, using the "-" that are equvilent to East and West?
A full Gravity detector would be like a compass that detects all directions, not just the North Pole?
A 2-Dimensional wave can have two vector rotations, expanding or contracting, an expansion vector would entail a spin left, and a contracting vector a spin right ( think of a fractal image, or a spinning "vertigo" label), wheras in 3-Dimensions, the Graviton would be an encompassing vector field, which produces no detectable particles or waves?.. One could label it as a perfect Fundemental Vacuum.
Iam certain you cannot detect the perfect fundemental Vacuum, so the Graviton must be undetectable, by its very nature, it a "particle" label, but it has been a "one-off" process in the early instants of the pre-universe bang?..a inflation wave/particle?
Graviton is a single particle that gave rise to inflation, which fluctuated out of the perfect fundemental Vacuum, it may be in the future there will one Anti-Graviton vector field?