We seem to be talking past each other.
My problem is not with Bayesian approach to confirmation. Afterall, evolutionary theory is largely based on this (sorry Popper, its not just metaphysics).
My problem is with the idea that confirmation points exclusively to MWI.
Take your gravity example. Multiple observations show us that gravity exists. Careful study can even lead us to a Newtonian analysis of it. We understand very well how mass is related to gravity, etc. But this doesn't tell us anything about how gravity is created.
There's a lot of conjecture about gravitons and Einstein's ideas about mass bending space-time are quite elegant. But nobody has observed any of these phenomena and the "source" of gravity confounds us still.
Likewise, when you perform your LHC experiments, you've made a proximate observation, but you have not observed the actual cause.
I repeat, If Many Worlds is False, LHC may still be failing through an unknown alternative mechanism. MW has more external support than, say the existence of a diety, but these experiments alone are not sufficient to cite MW as the probable cause.
For one thing, Many Worlds has a lot less empirical support (and no direct observation) compared to something like gravity. And the LHC experiment and your MW anthropic explanation has no specific link about MW being the underlying cause.
I ask again, other than circular reasoning, what is your basis for ignoring the possibility that MW is false and something else is preventing us from destroying the universe?
It is certainly true that many, many failures/delays in the LHC could be caused by something other than an anthropic effect. The probability of all of those events would be increased with the observation of successive failures. What exactly would the other options be? I can think of two: fraud and anti-science conspiracy. Both of these could be independently investigated and we could find good reasons to think that neither had happened. What alternative explanations would we be left with?
I don't know how relevant this part is but:
Likewise, when you perform your LHC experiments, you've made a proximate observation, but you have not observed the actual cause.
Explain this distinction.
Related to: How Many LHC Failures is Too Many?
My first reaction to this was that it had to be a joke, but I thought Less Wrong readers would like to know that The Times of London is reporting that repairs on the Large Hadron Collider have been delayed by overheating caused by a piece of bread, possibly dropped by a bird:
I'm rather confident that this is just a meaningless coincidence, but in light of the anthropic speculations last year about the LHC's technical difficulties, I thought this was worth sharing.
Hat tip MBlume