Any direction is as good as any other, but one will be chosen.
In this case, the ones at the big end of the pear act differently than the ones at the small end because their neighbors are different then the ones at the small end. And the mid ones behave as they do because of who their neighbors are.
The reply of colanderman seems correct, though perhaps not terribly enlightening.
I suppose, if the interactions with particles external to the nucleus are weak enough, that the nucleus could be in a quantum superposition of all/most/many orientations anyway? (Not sure whether I'm off-base here.)
https://en.wikipedia.org/wiki/Spontaneous_symmetry_breaking
Any direction is as good as any other, but one will be chosen.
In this case, the ones at the big end of the pear act differently than the ones at the small end because their neighbors are different then the ones at the small end. And the mid ones behave as they do because of who their neighbors are.
The reply of colanderman seems correct, though perhaps not terribly enlightening.