(November 10, 2014 at 4:10 pm)Pickup_shonuff Wrote: Ok..few more...for now...
Considering the balloon analogy, how can galaxies collide if the space BETWEEN them is expanding?
Why is it that we don't actually experience the expansion of space? Is it because of the gravitational field? As in... it keep us "bounded" to this particular bodily composition, in terms of persons, planets, solar systems, galaxies, superclusters, etc.?
I understand Krauss to be arguing something to the effect that space must RESULT from fluctuations in the quantum gravitational field... but isn't this "quantum foam" itself an ultra-microscopic region of space? Doesn't he just mean that space can be inflated and produce matter from prior energy?
I don't understand how space arises in superstring theory at all. In loop gravity, you have these loop objects which themselves provide you with elementary areas and volumes. In spacetime, this network looks like a foam. Space is then what you get when many of these are connected. If course they are quantum, so the empty space which we see may not contain a sharp number of knots and loops associated with a given volume, it may be a superposition of states with arbitrary numbers of loops, I don't know. What happens upon expansion (are new ones created or do they get thinned out?) is a very good question...
The fool hath said in his heart, There is a God. They are corrupt, they have done abominable works, there is none that doeth good.
Psalm 14, KJV revised edition
