[Ygg2]

Another fun possiblity I remember from Universe in a nutshell, is that Dark matter is gravitation leaking from other branes.

In your analogy rubber sheet analogy, it's about stacking another rubber layer on top of current one.

It has no prediction powers , but it would explain things like why gravity is so weak and why we can't detect it.

[ggm]

Analogies are great for explaining versions of complex theories, but they rarely prove or disprove the theory because they aren't a 1:1 mapping to the theory, they're analogous. Similar. But similar is not "is the same"