An article at FQXI on multiverse research they are funding seemed to finally give me an understanding of what this is all about:
These are the two conceptually hardest questions in cosmology, according to Raphael Bousso, a theoretical physicist at the University of California, Berkeley. They go to the core of what it means to exist as a human being making sense of the universe we find ourselves in. And, he adds, unfortunately, there is very little physical knowledge to go on when it comes to working out the answer.
Undaunted by the lack of tools to help them, theatrical physicists Eugene Lim of King’s College London, UK, and Richard Easther of the University of Auckland, New Zealand, are…
This all of a sudden made things clear: what is going on is “theatrical physics”, not “theoretical physics”. Going on like this about the multiverse is performance art. More.
Woit notes that the page (“Our Place in the Multiverse: Calculating the odds that intelligent observers arise in parallel universes—and working out what they might see” by Sophie Hebden) has been edited since October 24 to occlude that emphasis.
It’s hard to know why the page sponsors think they should hide the theatrics. Theatre, TED talks, elegant essays, and coffee table books are the meat of their thoroughly post-modern project. The multiverse thrives as a metaphysic in the absence of evidence (“It may go well beyond physics, and be the first physically motivated “metaphysics” we’ve ever encountered. ”). There probably cannot be any evidence (“There is information we need, but that we’ll never obtain, in order to elevate this into the realm of testable science”).
And it doesn’t matter to the proponents if there can be evidence or not. Our brains, many now believe, are shaped for fitness, not for truth. What follows: Once their beliefs become certified as science, evidence is merely an obstruction, something that needs explaining rather than experiencing. The pursuit of evidence itself will gradually become suspect.
See also: The multiverse is science’s assisted suicide
Post-modern physics: String theory gets over the need for evidence
Cosmic inflation theory loses hangups about the scientific method