was particularly interesting. I don't know about others, but the multiverse seems absolutely absurd to me. Peter Woit puts it very starkly in this blog post: multiverse is a get-out-of-jail-free card for any theory in trouble: just assume we're in the multiverse, and this automatically explains why our theory doesn't match up with experiment.
I'm not exactly sure why this is such an important issue.
Here is my reasoning: even IF a multiverse model of space/time(s?) existence was correct, we are more properly concerned with understanding how the "particular" universe WE happen to inhabit works. Unless parallel universes interact with each other (and we have some way of knowing about these interactions), what we will never know, and certainly never experience remains largely a theoretical thought-experiement.
I believe certain questions may well prove to be "intractible", the "fine-tuning" problem is probably one of them. My feeling is, the universe IS fine-tuned, and we will probably NEVER know WHY. I feel that creation is a dynamic and chaotic process with sensitive dependence on initial conditions. We would be extremely lucky to even guess what those initial conditions might be.
As such I suspect we will only EVER have an approximation of "the true nature of reality". Because it IS an approximation, it may have qualitative features superimposed upon it that reflect the nature of our capacity for thought, which could be (and perhaps unprovably so) extraneous.
That doesn't mean we should stop trying...we will no doubt get some useful information along the way. Newtonian physics, for example, was good enough to hit the moon, but not good enough to keep communication satellites working properly (there has to be a relativistic correction). No proper understanding of relativity...no communication satellites. I'm OK with Einstein being proved wrong someday, but that doesn't mean the newer theory will be the last word. I don't think there CAN BE a last word, at least not with these brains we have.
It seems to me the heart of this debate is more of a philosophical discussion about how to explain the actual with the theoretical than a discussion of "what really is". Everyone seems to feel the standard model isn't quite good enough for answering our questions, but the possible alternatives/extensions of it seem to have supporters based on methodology (one group feels "good explanation of observable penomena" is the best criterion for a new theory, another feels that some sort of "sensibility and coherence" is the best criterion...to my knowledge all current theories have deficits in both areas).
Tl;dr version: if you don't KNOW, what you BELIEVE ought not to come under attack solely on the grounds that you don't know. Not all has been revealed yet (and may not ever be).
First, if we were really concerned with "fine tuning" being a problem then we would have given up on the Higgs search long ago. Why not keep looking for SUSY particles? We really have no clue what the mass of a squark or selectron is. We have to keep looking as long as there is a chance to "fine tune."
Second, SUSY hasn't been a seriously popular idea in recent years (to the best of my knowledge.) I just wonder what people are going to say when we reach the experimental limits to start detecting string theory effects and they aren't found right away. Is tolerance (and perhaps funding) of such a search dependent on how popular a theory is? I don't think that makes for good science.