1. Is it simply just a mathematical (orbital) coincidence, that only one side of the moon is ever visible to us. ? I suppose that will change in eons to come as one of us slows down ?
2. I heard it proposed - If the earth did not have a molten core - earth would not have any gravity. True ?
3.Why do we rotate around the sun in approximately the same 'flat' orbit ? (GR makes space three dimensional so why not a 3D. kind of multi orbit rotation ?)
Hope these questions are not to elementary or stupid
