In this world I'm building, I need it to be possible to have enclosed spaces/worlds connected to the main one. Ideally the main world would closely resemble ours, with the same laws of energy/physics/time/space etc, although differences will have to be allowed if that's the only way to accommodate the existence of these spaces. Time needs to progress differently in these spaces in relation to the main world, with 1 hour in the main world = to 24 hours in the secondary ones. Gravity should feel the same. If the size of these secondary worlds is significant, they would be at most 1 000 000 square feet.
As for the connection between the worlds, I feel with enough research and exaggeration I can use portals/wormholes. I haven't figured it out yet, but there's enough information on the theory behind them that I should be able to. If you have ideas or summaries that you'd like to add it would still be appreciated.
Right now the closest I'm getting is some kind of enclosed system out in space, in distant rotation / accelerating to the point that time will be experienced differently in the two places. I would prefer some kind of stationary or inter-dimensional (?) space if at all theoretically possible. It would also be acceptable if the secondary world was scaled down and enclosed somewhere on the primary one, though I'm not sure what other changes a scale change would indicate.
I'm sorry for asking, but I haven't been able to find any theoretical or pseudo-scientific explanations for what I'm suggesting. If this idea sounds familiar to you and I'm just not using the right terms to search for it, I would appreciate if you shared those instead.
Browsing this website has been hugely helpful to me in building this world so far, so even if this is a dead end I appreciate just having a place to ask the question.