Ok, either MWI is true or it is not true, correct? And either the LHC destroys planets or it doesn't. So we have 4 possibilities.
MWT-LHCD; MWF-LHCD; MWT-LHCND; and MWF-LHCND
If MWT-LHCD: you will observe lots of LHC test failures. The more test failures the higher this probability.
If MWF-LHCD: You will die.
If MWT-LHCND:The LHC will work and not suffer an unreasonable amount of delay.
If MWF-LHCND: The LHC will work and not suffer an unreasonable amount of delay.
It is a little more complicated than that since there are other hypotheses that might better explain test failures, but in general, the more test failures you see the higher you should estimate the probability of option one. Nowhere in this proof did I assume the truth of MWI.
there are other hypotheses that might better explain test failures
This quote is key. Other hypotheses could produce the same outcome as MWT-LHCD. Therefore MWF-LHCD actually has two possible outcomes. MW is false and we die. or MW is false and something else keeps us from dying.
The only reason we'd ignore the second possibility is if we assume MW is true and other hypotheses are irrelevant.
It may not be a bad assumption, but this is hardly empirical proof.
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