nDominant force on astronomical size scale.
nNeed very close balance of gravity and cosmic expansion for stable
uIf gravity weaker by 1 in 1060, universe expands too quickly, no
galaxies or stars formed.
uIf gravity stronger by 1 in 1060, universe collapses without forming
galaxies or stars.
nGravity is fine-tuned to 1 part in 1060.