The world is infinite right now, its a sphere, it never has a end.
I see what you did there.
If the sky and Earth seems infinite in all directions, then the sun is withing the sky among the clouds I suppose.
Then if the sun is a small orb of glowing something, lets say dense gas. Then what if there is more that we don't see.
Now imagine that if I dig down I will stumble onto a cavern, but not an ordinary cavern; it has light from another duplicate sun just like ours but with a little more gas than ours. And if that is then can such exist underground? If so is there a surface? Does that mean we live in a giant cave ourselves?
My cave theory:
