Jejudo, South Korea
Regardless of whether there really are alternate universes out there as this article points to, or even if it is true, I want to point out that it doesn't really matter if you describe the universe as one or multiple. Universe, on at least one description, is just everything there is so it's still a whole with many parts, it's just a whole lot bigger than we generally imagine.
So what's the big deal? Honestly, I don't know, but we do have some no-nonsense realists out there (and, let's be honest, these forums wouldn't be half as fun if they weren't around) who say things like, "There is a world and there is a way that it is." On the face of it, who would disagree with that? There's really nothing wrong with it. It's a perfectly useful description and as a working assumption it has helped us do many things.
But it is still nothing more than a description. If we change it to "There are worlds and there are there are ways in which they are" what really changes? Not much, except that it opens up the possibility of multiple descriptions for multiple worlds and, perhaps, multiple descriptions of singular worlds, and singular descriptions of multiple worlds.
The only problem I see is when words like 'just' ,'only','merely' slip into the conversation and we start ridiculing others who believe anything different from this one description. Here, we confuse two perfectly good descriptions with a right description and a wrong one. No one is denying that we can get things wrong and the people do get things wrong. It doesn't mean anything goes, it only means that there are more descriptions that are perfectly legitimate and that, maybe, we should be looking for more descriptions, not less.
The idea of alternate universes, multiple worlds etc. is often seen as a new, exotic and exciting idea, but historically, it's a frighteningly old idea. Most (Dare I say all?) cultures accept and never doubt, not just the possibility of other worlds, but the reality of them. We live in a world and we live in worlds and there is no contradiction there because we are talking about descriptions, not the world(s) in and of itself.
And how do you get out of, or why would you want to get out of, this ability to describe?