Theoretically space is infinite, as it is the ultimate container. So how does it expand? For example if you keep adding objects to a room the room isn’t gonna expand, you’re gonna run out of space. So how does space expand if the cause of it is apparently dark matter being created?
In the beginning, the universe was all packed down into a very small area. Then the big bang happened, and space started expanding.
Space isn’t like a room, it’s more like the inside of a balloon.
We don’t know if space is infinite.
We could travel at light speed toward the edge of the observable universe, where the cosmic microwave background radiation from the big bang has reached, but even at light speed we’d never be able to catch up. It’s had a couple billion years’ head start.
Especially since the expansion of space is accelerating. We don’t know why it’s doing that. A naive hypothesis would have expected it to fall back together, like a cosmic dust cloud gravitates together.