In this article, some researchers say this so-called “dark flow” is a sign that other universes nestle next door.
What’s your opinion on this matter?
I’ve been somewhat following this since it was first announced last year, and I think it’s still too early for anybody to really have much of an informed opinion. After all, there’s still debate on whether or not there even is a significant effect at all, so it might still turn out to be just a quirk in the data. That the findings were apparently repeated in the more recent story is noteworthy, however.
Also interesting is that Mersini-Houghton apparently managed to predict this ‘dark flow’; from quickly skimming her paper(s), it appears that she treats the so-called ‘string landscape’, basically the set of vacuum states allowed by string theory, as the space over which the universal wave function propagates in order to ‘settle’ into a (locally) minimal vacuum, effectively ‘choosing’ the properties of the universe (such as, for example, the cosmological constant) from the set of possibilities. In this process, she claims that there might be some interaction (or rather, if I’m reading it correctly, quantum mechanical entanglement) with ‘neighbouring’ vacuum solutions (and thus, universes or at least possible universes), which gives rise to dark flow and apparently also to the recently detected cold spot, and predicts the detection of another, similar cold spot opposite that one; so basically that’s a testable prediction which would, I believe, lend strong support to string theory, though I’ not entirely sure if this prediction is actually unique to it – it might be that there’s another way to account for similar entanglement that doesn’t rely on the string landscape.
But I’m no expert, so hopefully somebody comes along able to explain these things in greater detail. But it looks like something to watch, at least tentatively.