I’ve come to realize that, when it comes to the Many Worlds Interpretation (MWI) of quantum physics, there is at least one aspect of it that’s poorly understood. Since it’s an aspect that even proponents of MWI recognize as an issue, I thought I’d take a stab at explaining it. (If nothing else, I’ll have a long reply I can link to in the future.)
The issue in question involves what MWI does to probability. Essentially, our view of rare events — improbable events — is that they happen rarely, as we’d expect. Flip a fair coin 100 times; we expect to get heads roughly 50% of the time.
But under MWI, someone always gets 100 heads in a row.
I finally finished Our Mathematical Universe (2014) by Max Tegmark. It took me a while — only two days left on the 21-day library loan. I often had to put it down to clear my mind and give my neck a rest. (The book invoked a lot of head-shaking. It gave me a very bad case of the Yeah, buts.)
I debated whether to post this for Sci-Fi Saturday or for more metaphysical Sabbath Sunday. I tend to think either would be appropriate to the subject matter. Given how many science fiction references Tegmark makes in the book, I’m going with Saturday.
The hard part is going to be keeping this post a reasonable length.
I was surprised to discover I’ve never posted about the Many Worlds Interpretation (MWI) of quantum physics — I would have sworn I had. I’ve mentioned it a few times, and I know I’ve discussed it in comment sections, but it seems I never tackled the subject explicitly for the record.
It’s been on my mind lately because others have talked about it. Sean Carroll’s book promoting it generated a wave of discussion. The final push for me was Jim Baggott’s Farewell to Reality, which consigns MWI to the “fairy tale physics” heap.
Since I quite agree, this seems a good followup to yesterday’s post.