For me, a universe in superposition of all possible universes is just as "absurd and objectionable" as one with physical doubling. Further, I think the subdivision into discrete "branches" is far more than "mathematical convenience", it's what we experience.
This touches on something else that bothers me: the MWI seems very mathematical. You mentioned Tegmark, and if his Mathematical Universe Hypothesis was correct, the MWI would fit right in. But I have a hard time seeing how we get from a wavefunction to physical reality. What does it mean for the atoms in my brain to be in superposition? What does it mean for them to know different things? And be smeared out physically because I may have gone different places depending on outcomes. Mathematically, the MWI is easy. Physically, it's a big ask (in my eyes).
FWIW, my primary objection to the MWI is that it's a non-physical theory with no experimental evidence to support it or pick it out from other interpretations. I have for a long time been troubled by our modern culture's increasing detachment from physical reality (as evidenced by the current situation), and it concerns me when science seems more like science fiction.
But fundamentally, I require experimental evidence to believe large objects can be in superposition.
All that said, ever read Greg Egan's Quarantine? The MWI is fundamental to that story, too.
>If you’re bothered by the thought of other versions of yourself experiencing different versions of reality, then, yeah, Everettianism probably isn’t for you. But then, to loop back to Max Tegmark and his levels of multiverses for a second, you should probably take a pass on inflationary cosmology as well, for more or less the same reason.
I never could get Philip Ball to give a straight answer about whether things that have exited our cosmological horizon still exist.
I know little enough about both subjects (QM and the Great Schism) of this blog post to get into trouble. It’s beyond impressive, however, and certainly the first time in history, that these great controversies have been linked, which is fun. Is it the Father AND the Son, or the Father THROUGH the Son? Perhaps it’s just a superposition of different wave functions! In general, I am highly distrustful of attempts to link art and culture topics to the inherent “uncertainty” of QM, but this one was fun to read. Also liked the reference to the short story (Divided by Infinity) that you mentioned. Will look it up!
There is a lot of emotion tied to QM interpretations, none more so than the Everett one. Maybe because it's the stark opposite of the ones that make the observer special. QM seems like a Rorschach test for revealing people's preferred metaphysics. Myself, I think pure wave mechanics make more sense than the alternatives. I feel like it would have been accepted decades ago if not for the implications. But I say that as an ontic structural realist.
Thanks for clearing up a lot of the multiverse stuff. A lot of popularizers made it sound like the universe is a bunch of train stations on the same line except with alternative versions of every possible interaction. As a train fan, I started wondering about the route map and gave up.
Another way of thinking about you never living in a "universe" where you die is that when you die, everything unique to your experience is garbage collected as the reference count is decremented. That's how I'd do it in software. Looked at from the right angle, it's pretty poetic. All that is left when one dies is one's influence on those still living.
Also, some years back I read a popular account of an experiment with an observer reacting to an event and an observer of that observer in which the two observers did not get consistent accounts of the event, though I assumed that the statistics would match if the experiment were run and rerun. Is that 100% bogus. I could have been in an alternate universe or dreaming.
There was a big splashy thing not too many years ago about a scheme with one person doing an experiment in a box and another observing them from outside that was written up as creating a conflict between what the person in the box would say that the person outside would see and what they would actually observe. Given that the whole thing was rooted in theoretical expectations, though, I could never really figure out why the person in the box would be doing the calculation any differently than the person outside. Which made the whole thing seem like "Two people will predict different outcomes for a complicated scenario if one of them is doing it wrong," which is not a super exciting result...
I think the experiment ("Wagner's friend", I think?) is meant to show the inconsistency of collapse theories as the uncertainty of the outside observer is purely classical? Someone would have to somehow pass the internal observer through the equivalent of a beam splitter and show that an "interference pattern" doesn't appear though, and that seems like a thought experiment for someone with bigger brains than me.
For me, a universe in superposition of all possible universes is just as "absurd and objectionable" as one with physical doubling. Further, I think the subdivision into discrete "branches" is far more than "mathematical convenience", it's what we experience.
This touches on something else that bothers me: the MWI seems very mathematical. You mentioned Tegmark, and if his Mathematical Universe Hypothesis was correct, the MWI would fit right in. But I have a hard time seeing how we get from a wavefunction to physical reality. What does it mean for the atoms in my brain to be in superposition? What does it mean for them to know different things? And be smeared out physically because I may have gone different places depending on outcomes. Mathematically, the MWI is easy. Physically, it's a big ask (in my eyes).
FWIW, my primary objection to the MWI is that it's a non-physical theory with no experimental evidence to support it or pick it out from other interpretations. I have for a long time been troubled by our modern culture's increasing detachment from physical reality (as evidenced by the current situation), and it concerns me when science seems more like science fiction.
But fundamentally, I require experimental evidence to believe large objects can be in superposition.
All that said, ever read Greg Egan's Quarantine? The MWI is fundamental to that story, too.
>If you’re bothered by the thought of other versions of yourself experiencing different versions of reality, then, yeah, Everettianism probably isn’t for you. But then, to loop back to Max Tegmark and his levels of multiverses for a second, you should probably take a pass on inflationary cosmology as well, for more or less the same reason.
I never could get Philip Ball to give a straight answer about whether things that have exited our cosmological horizon still exist.
I know little enough about both subjects (QM and the Great Schism) of this blog post to get into trouble. It’s beyond impressive, however, and certainly the first time in history, that these great controversies have been linked, which is fun. Is it the Father AND the Son, or the Father THROUGH the Son? Perhaps it’s just a superposition of different wave functions! In general, I am highly distrustful of attempts to link art and culture topics to the inherent “uncertainty” of QM, but this one was fun to read. Also liked the reference to the short story (Divided by Infinity) that you mentioned. Will look it up!
There is a lot of emotion tied to QM interpretations, none more so than the Everett one. Maybe because it's the stark opposite of the ones that make the observer special. QM seems like a Rorschach test for revealing people's preferred metaphysics. Myself, I think pure wave mechanics make more sense than the alternatives. I feel like it would have been accepted decades ago if not for the implications. But I say that as an ontic structural realist.
Thanks for clearing up a lot of the multiverse stuff. A lot of popularizers made it sound like the universe is a bunch of train stations on the same line except with alternative versions of every possible interaction. As a train fan, I started wondering about the route map and gave up.
Another way of thinking about you never living in a "universe" where you die is that when you die, everything unique to your experience is garbage collected as the reference count is decremented. That's how I'd do it in software. Looked at from the right angle, it's pretty poetic. All that is left when one dies is one's influence on those still living.
Also, some years back I read a popular account of an experiment with an observer reacting to an event and an observer of that observer in which the two observers did not get consistent accounts of the event, though I assumed that the statistics would match if the experiment were run and rerun. Is that 100% bogus. I could have been in an alternate universe or dreaming.
There was a big splashy thing not too many years ago about a scheme with one person doing an experiment in a box and another observing them from outside that was written up as creating a conflict between what the person in the box would say that the person outside would see and what they would actually observe. Given that the whole thing was rooted in theoretical expectations, though, I could never really figure out why the person in the box would be doing the calculation any differently than the person outside. Which made the whole thing seem like "Two people will predict different outcomes for a complicated scenario if one of them is doing it wrong," which is not a super exciting result...
I think the experiment ("Wagner's friend", I think?) is meant to show the inconsistency of collapse theories as the uncertainty of the outside observer is purely classical? Someone would have to somehow pass the internal observer through the equivalent of a beam splitter and show that an "interference pattern" doesn't appear though, and that seems like a thought experiment for someone with bigger brains than me.
Thanks for explaining that. I was in a 50:50 superposition state as to whether I actually read such an article.