For what it’s worth, I’m familiar with the philosophy surrounding the many worlds interpretation (MWI, and while I can’t vouch for all the argumentation in that paper, I think that (a) quantum immortality is not a consequence of the MWI, and (b) this paper offers a valid argument for (a).
On a more meta point, I think the strategy of “hear something I disagree with → look for a debunking” isn’t likely to lead you to truth—if you were wrong, how would this strategy help you find out? You could carefully check both the argument you disagree with and the debunking, seeing which is flawed or finding a valid synthesis of both, but from the tone of your post I imagine you finding something that counts as a ‘debunking’ and not pursuing the matter further. I think it would be more wise to think carefully about the claims in the article, look for counterarguments, think carefully about those, and come to your own conclusions (where perhaps the ‘thinking’ involves discussing the issues with a friend, or on LessWrong or a similar forum). If you can’t make heads or tails of the issue, but think you can identify experts who can, then one other option would be to defer to expert consensus. Sadly, in this case, I can’t find a poll of experts, but looking at the Wikipedia page on Quantum Suicide and Immortality only quotes two experts (Max Tegmark and David Deutsch), neither of whom agree that quantum immortality works. As such, I suspect that belief in quantum immortality is very uncommon among experts, since otherwise I’d expect to see an expert quoted in the Wikipedia article supporting the view that quantum immortality is real.
For what it’s worth, I’m familiar with the philosophy surrounding the many worlds interpretation (MWI, and while I can’t vouch for all the argumentation in that paper, I think that (a) quantum immortality is not a consequence of the MWI, and (b) this paper offers a valid argument for (a).
On a more meta point, I think the strategy of “hear something I disagree with → look for a debunking” isn’t likely to lead you to truth—if you were wrong, how would this strategy help you find out? You could carefully check both the argument you disagree with and the debunking, seeing which is flawed or finding a valid synthesis of both, but from the tone of your post I imagine you finding something that counts as a ‘debunking’ and not pursuing the matter further. I think it would be more wise to think carefully about the claims in the article, look for counterarguments, think carefully about those, and come to your own conclusions (where perhaps the ‘thinking’ involves discussing the issues with a friend, or on LessWrong or a similar forum). If you can’t make heads or tails of the issue, but think you can identify experts who can, then one other option would be to defer to expert consensus. Sadly, in this case, I can’t find a poll of experts, but looking at the Wikipedia page on Quantum Suicide and Immortality only quotes two experts (Max Tegmark and David Deutsch), neither of whom agree that quantum immortality works. As such, I suspect that belief in quantum immortality is very uncommon among experts, since otherwise I’d expect to see an expert quoted in the Wikipedia article supporting the view that quantum immortality is real.