A Soap Bubble Universe
We don't know why the Universe is the way it is. We don't know why it came into being, or how. We don't know what it has the structure it does, with stars and galaxies, and clusters of galaxies. Nor do we know why physical constants take the values they do. They seem finely tuned so that atoms can form, and molecules can form from atoms, and planets can orbit stars which burn at such a rate that life can evolve on planets that orbit around them. Calculations have been done that impy if any of the physical constants were different by so much as one part in 10^{40} , electrons could not stably orbit the nucleus, and planets could not orbit stars for long enough for life to evolve on them.
We don't know if our Universe is the only Universe. It may be that there are lots of Universe, all with a difference set of physical constants. Some of these will evolve into deformed and grotesque things, some may flower with life and knowledge. We can imagine many Universes, all possible Universes, arranged like soap bubbles.
But wait... A different set of physical constant could mean that space itself has a different energy. These Universes all with difference energies associated with space could all end up fighting for dominance, with those lower energy Universes gradually absorbing the higer energy Universes along the boundary between them.
How would we know if this is happening? The Universe would be filled with 'Great Attractors' and 'Great Repellers', attracting or repelling all the matter around it. This may be the fact. The Milky Way is being attracted to something on the opposite side of the Milky Way from us. We know nothing of it's nature.
