Actually, I think it might (though I'm obviously open to correction) if you take the anthropic principle as a given (which I do not).
One thing you're missing is that there are two events here, call them A and B:
A. LHC would destroy earth
B. LHC works
So the events, which are NOT independent, should look more like:
The LHC would destroy earth, and it fails to operate
The LHC would destroy earth, and it works
The LHC would not destroy Earth, and it fails to operate
The LHC would not destroy Earth, and it works
Outcome 2 is "closer" to outcome 1. More precisely, evidence that 2 occured would increase our probability of both A and B, which would therefore decrease the probability of event 3 relative to event 1.
The fact that 2 is invisible means that we can't tell when it has happened. But there is a chance that it is happening that would increase with each subsequent failure, as Eliezer noted.
This is far from formal but I hope I'm getting the gist across.
simon,
Actually, I think it might (though I'm obviously open to correction) if you take the anthropic principle as a given (which I do not).
One thing you're missing is that there are two events here, call them A and B:
A. LHC would destroy earth B. LHC works
So the events, which are NOT independent, should look more like:
Outcome 2 is "closer" to outcome 1. More precisely, evidence that 2 occured would increase our probability of both A and B, which would therefore decrease the probability of event 3 relative to event 1.
The fact that 2 is invisible means that we can't tell when it has happened. But there is a chance that it is happening that would increase with each subsequent failure, as Eliezer noted.
This is far from formal but I hope I'm getting the gist across.