Ok - fair warning - Non-physicist asking dumb-assed questions here again. I've been reading a lot of Einstein, Feynmann, Ferris etc. I'm just loving this stuff.
But I suddenly found myself looking at the 4-D sphere concept of our expanding universe, as well as the distortion of spacetime caused by objects with mass and so on, and suddenly thought - this 4th spacial dimension (that we cannot comprehend) through which our universe is expanding - is this actually the dimension of time?
Is the time dilation experienced closer to bodies with mass not a literal curving of the skin of our 4-D sphere in toward its center? So at that point in spacetime the radius is increasing more slowly compared to the radius further from the mass?
I'm afraid my brain just keeps failing when I try to incorporate other concepts from GR into this view - such as time dilation with increasing speed. However the shortening of length of an object in the direction of travel kind of makes sense there as well but only if there was a similar unilateral distortion near bodies of mass.
And then I got to thinking about black holes and their extreme curvature - are they literally stopping universal expansion at their point of singularity such that deltaR=0 and therefore time stops? Or do they even stretch right back to R=0?
Ok, enough of my sillyness - can someone put this into perspective for me?