Let me go back a little to my earlier post (#7) about "absolute spacial orientation."
Is your cube moving (e.g., relative to the earth) when you want to determine which face is up?
I don't recall it being said that the cube is stationary and affected only by the acceleration of gravity. That distinction might make a difference in how you detect which face is up relative to you, earth, or the floor. For example, what if the cube were on a stick being swung around a pivot in the stick and parallel to the floor? Now, the "6" might be up relative to you, earth, or the floor, but the acceleration detected might be almost perpendicular to that reference.
BTW, my earlier comment was not so much about the spelling as about the meaning of "absolute." In the example I just gave, one might define that "up" as an absolute orientation relative to earth.
John