At Time Zero minus a moment, this same quantity changed its character in the mathematics and became 'imaginary'. This is a mathematical warning flag that something dreadfully unexpected has happened to time as we know it. Steven Hawking has looked at the mathematics of this state using the fledgling physics of Quantum Gravity Theory, and confirms that at the Big Bang, time was murdered in the most thorough way imaginable. GR says specifically that space is not a passive stage upon which matter plays out its dance, but is a member of the cast. When you treat both galaxies and space-time together, you get a very different answer for what happens than if you treat them separately, which is what we instinctively always do.
Curved space distorts the paths of particles, sometimes in very dramatic ways.
If you stepped into a space ship and tried to travel to the edge of the universe and look beyond, it would be impossible. The curvature of space would bring you right back, in something like the way the curvature of Earth would bring you home if you flew west and never changed course. In other words, the universe has no edge in space. There is nothing beyond the farthest star. As a mental anchor, many have used the expanding balloon as an analogy to the expanding universe.