On Mon, Nov 4, 2024 at 5:18 PM Brent Meeker <[email protected]> wrote:
*>> Branch counting could never work. * > > > *> The other advocate of MWI I know insists that it only makes sense for > branch counting.* *Here's why branch counting won't work: I measure the spin of an electron in the vertical direction and both the electron and I split into two, and there's a 50% chance "I" will see spin up and a 50% chance "I" will see spin down. So far branch counting seems to work. But before I started I made up my mind that if I see spin up I will do nothing, but if I see spin down then I will wait for 10 minutes and then measure the electron spin a second time but this time along the horizontal axis. And so the spin down world splits again into a spin right world and a spin left world. So now there's only one branch in the spin up line BUT three branches in the spin down line. If you use branch counting you'd have to say that in the first measurement the probability was not 50-50 as you originally thought, instead there was a 25% chance I would see spin up in a 75% chance I would see spin down. But something I do now can't affect the probability of an experiment I performed 10 minutes ago.* *That's why when I draw a diagram of the worlds splitting on a piece of paper or a blackboard even though the lines I draw are two dimensional I like to think of those lines is having a little 3D thickness, the total sum of all the thickness of all the branches in the multiverse remains constant but each time a world split the resulting worlds become more numerous but thinner; although it always remains true that if you're betting on which universe you are likely to be in you should always place your money on being in the thicker one.* *I want to emphasize that this thickness business is not to be taken literally, it's just an analogy that I happen to like, you may not and that's OK because there's no disputing matters of taste. But disliking branch counting is not a matter of taste because such a dislike is not subjective, branch counting objectively doesn't work. * *John K Clark See what's on my new list at Extropolis <https://groups.google.com/g/extropolis>* cjj -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion visit https://groups.google.com/d/msgid/everything-list/CAJPayv0M4qjh2hkikMyZrFYs4gmJXVGaY_52jYFjT7%3DC_GhHhw%40mail.gmail.com.
