In his final paper, with Hertog, scaling back the multiverse? From Philip Goff at the Guardian:
But if all of the universes have exactly the same laws – as in Hawking and Hertog’s proposal – the problem returns, as we now need an explanation of why the single set of laws that govern the entire multiverse is fine-tuned.
Hertog seems not to agree, arguing that the paper does make progress on fine-tuning: “This paper takes one step towards explaining that mysterious fine-tuning … It reduces the multiverse down to a more manageable set of universes which all look alike.” However, this merely puts off the explanation of fine-tuning, for the result is that the laws underlying the generation of the multiverse are fine-tuned. We now need to explain not only why our universe is fine-tuned but why every universe is fine-tuned! In terms of explaining the fine-tuning, this is not a step forward but a step back. More.
Goff wants a “scientific account of fine-tuning.” What if the scientific account is that there is some sort of intelligence inherit in or beyond the universe? Then we must choose between “science” and reality.
Rejection of multiverse thinking may strengthen the case for God by default. But the enthronement of evidence-free irrationality that multiverse theory embodies is not evidence for God as such. It would, however, cause careful thinkers to reconsider all alternatives.
The problem with multiverse theory is not that there might not be other universes but that they are wished into existence in order to avoid the implications of the fine-tuning of our universe. Then comes the war on falsifiability
See also: Stephen Hawking’s final theory scales back multiverse
What becomes of science when the evidence does not matter?
The multiverse is science’s assisted suicide
and
Question for multiverse theorists: To what can science appeal, if not evidence?