Recently I was reading this article on the rotation of galaxies and started asking these questions. http://phys.org/news/2014-10-statistical-bias-spiral-galaxies.html 1. Every galaxy has an axis with an orientation (tilt - for lack of a better word)...but how can this orientation be DEFINED if there is no fixed point of spatial reference in the universe? That is to say...no up or down, no center or periphery. 2. If the orientation could be defined...is the orientation of every galaxy determined in a completly RANDOM fashion?
To further explain the question...imagine that planet earth was contained inside a cube, and that its rotational axis could be described by plotting the extension of its axis in a straight line to points on the inside of the cube. In the universe this is NOT possible...because it has no identifiable context to serve as a reference for the axial orientation of any particular galaxy. Correct me if I'm wrong!
The point of observation is the point of reference in this case. That is the orientation is relative to the telescope through which the galaxy is viewed.
In a sense, what you'e saying is true. There is no absolute set of reference points surrounding the universe to which things can be compared. However, comparisons can be made between the various objects within the universe. To bring up your example, rather than comparing the earth's axis to the surrounding box, we could instead compare it to the nearby moon, or another selected object. In the end, these comparisons will be somewhat arbitrary, and depend on the chosen reference point. However, if the point is to make comparisons between objects (e.g. Galaxy X has an axial tilt of 25 degrees relative to the Milky Way), then they serve their purpose prefectly well.
