Reply To: Does the influence of gravity extend out forever?

No, it's not true. Gravitational attraction does not extend past galaxy clusters. Only the edge of each gravity group is affected by gravity. Spacetime then ceases to function like gravity. It's not that as you leave a galaxy group, a star's gravitational attraction becomes too weak to notice. Rather, outside of the galaxy group, the gravitational force vanishes totally. It stretches as far as the earth's age in light-years. And that's before you factor in the numerous things that eventually merged to form the earth. As a result, the earth's gravitational field is about a sphere with a radius of 4.5 billion light-years.