Viewing a single comment thread. View all comments

EmptyTotal t1_jc4uxl1 wrote

To start with a little nitpick:

>Joy says that “most” universes are ones where life did not evolve, but you cannot have “most” of infinity.

You can have "most" of infinity. For example, most whole numbers are not prime, and both of those sets are (the same size of) infinite. Still, the ratio of the number of primes to the number of non-primes below a certain value is small (and tends to zero as that value tends to infinity).

Personally, I don't think Everything attempts to comment on Many Worlds in any meaningful way, because its multiverse is fundamentally unlike the one Many Worlds would predict. As you highlight, seemingly every universe in Everything contains some sort of version of the same characters, and they all have the same personalities deep down. For "every you is you" to be a meaningful statement means ruling out the vast majority of Many World universes that are populated by people a bit like you, but a bit like someone else. (And requires inserting a fundamental idea of a "person" that isn't emergent from particles.)

Fundamentally, Everything is a story about characters, not metaphysics, using wacky soft sci-fi as a backdrop. It aims to convey a message about love and relationships relevant to our single universe.

To address this:

>To me, I find the many-worlds interpretation is a way of ridding ourselves of the uncomfortable idea that the laws of physics are not deterministic. Having no answer to explain why a superposition reduces to one state and not another is disconcerting. Saying that a superposition does reduce to another state, except it occurs in a dual universe we cannot currently observe, is an easy way to remove the question altogether.

I think your take on Many Worlds is a little off. The interpretation is actually the idea that superpositions are never reduced, which naturally leads to a "multiverse". One is not invented arbitrarily. In terms of postulates it's actually the simplest way of stating quantum mechanics, because interpretations that make the wave function "collapse" require an extra rule that is mathematically ugly, not clearly defined, and doesn't even change the experimental results (to any extent that is currently measurable).

>[In MWI] We are just one sample in an infinite list of possibilities, so there is no meaning to why we happen to be in this state.

On the contrary, there is just as much or as little meaning (or "free will") in Many Worlds as in any single-universe model. (To circle back to the start:) Yes, there may be an infinite number of "you", but most of them will make the same sort of choices, derived from their biology and experiences, as you do. Only in a vanishingly small proportion of worlds will some freak quantum event have you acting counter to your own history.

175

Seek_Equilibrium t1_jc5t3ev wrote

> You can have “most” of infinity. For example, most whole numbers are not prime, and both of those sets are (the same size of) infinite. Still, the ratio of the number of primes to the number of non-primes below a certain value is small (and tends to zero as that value tends to infinity).

The difference between asymptotic density vs proportions of infinity is relevant here. Most numbers are non-primes only in the first sense, not the latter. Problem is, the asymptotic density depends on the ordering of the set, and not all infinite sets have natural orderings like the number line does.

For example, you can’t simply take the asymptotic density of an infinite set of coin flips to get frequencies of 0.5 for both heads and tails, because that depends on the ordering of the set being {H,T,H,T,H,T…} or {H,H,T,T,H,H,T,T,…}, or similar. But there’s no reason to privilege that ordering over {H,H,T,H,H,T,H,H,T,…}, which will give an asymptotic density of 0.67 for heads and 0.33 for tails. It might seem like something’s wrong with that last ordering, like we’d eventually run out of H’s or something, but in an infinite set we won’t ever run out.

The lesson is just that you can’t define frequencies or proportions in infinite sets that lack natural orderings. The number line is the exception, not the rule.

13

throwawayski2 t1_jc6azmd wrote

>The lesson is just that you can’t define frequencies or proportions in infinite sets that lack natural orderings. The number line is the exception, not the rule.

You may need to explain a bit more, because as a mathematician that just seems plain wrong:

You can define sets of any proportion on any bounded set of R^n (an infinite set with no natural ordering for n > 1). That's a very basic thing in Measure Theory. For example you can just generalize the Cantor set to any dimension to get an infinite set of points that has no volume.

Edit: just some minor correction of my part

14

Seek_Equilibrium t1_jc8t769 wrote

How does this help define the frequency of an element within the infinite set?

1

throwawayski2 t1_jcb56n3 wrote

I didn't mention frequency if you read again. Frequency - at least in the probabilistic sense - requires a observational component, that is reasonable to assume when discussing possible worlds. But that has nothing to dobwith infinity but with the fact that you can't observe possible worlds.

But if you talk about proportions or the probability of choosing an element from a given subset (what I suppose you actually mean by frequency), then this is exactly the way you define these things in Mathematics when dealing with infinite sets.

2

Seek_Equilibrium t1_jcbheol wrote

> But if you talk about proportions or the probability of choosing an element from a given subset (what I suppose you actually mean by frequency), then this is exactly the way you define these things in Mathematics when dealing with infinite sets.

The phrase “from a given subset” is catching my attention. Are you talking about defining a probability measure on a finite subset of an infinite set? Because if so, that of course wouldn’t bear on the core issue being discussed of whether and how a unique probability distribution could be defined over an entire infinite set - but I am probably missing what you’re truly aiming at so maybe you can clarify.

1

throwawayski2 t1_jccd2r6 wrote

No, it can also be defined on infinite subsets. That's why I mentioned Cantor sets, because these are measurable uncountable sets, such that choosing an element from it (given uniform choice from the bounded set on which it is defined) has probability 0 (which is different from our finite intuition, that it is impossible).

It is basically just a generalization of the concept of volume.

2

EmptyTotal t1_jc6kbrc wrote

>The lesson is just that you can’t define frequencies or proportions in infinite sets that lack natural orderings. The number line is the exception, not the rule.

In the context of multiverses, there are natural ways of ordering them. In MWI for example, you could consider universes that first differ from ours by a more recent branching event to be "closer" than ones that branched further back. Then whatever density you want can be defined in the set of universes that diverged later than time t, as t is taken to zero.

Frequency in a multiverse shouldn't really be any less intuitive than a frequency measurement in our single universe. If space is infinite, then it also contains infinite planets. But it is still obvious that most of space is empty.

(Just like it is obvious that infinite coin flips should be time-ordered when referring to their "frequency".)

4

Seek_Equilibrium t1_jc7eikj wrote

The examples you give are interesting ways of recovering a natural ordering. It makes me wonder, in the case of spatiotemporally disconnected cosmological multiverses, if some kind of n-dimensional “similarity measure” could be used in principle, with our universe as the reference.

Of note, though, this…

> (Just like it is obvious that infinite coin flips should be time-ordered when referring to their “frequency”.)

… is problematic unless there is some actual infinite sequence of coin flips that we can refer to. Any hypothetical infinite sequence of coin flips could have any hypothetical time-ordering, so the original problem just rearises in the form of specifying the order of the flips in time.

0

python_hunter t1_jc8099y wrote

TL;DR "thank you for the correction" ;D

0

Seek_Equilibrium t1_jc81w1w wrote

Not a single thing in that comment “corrected” what I said previously. I made a point only about infinite sets without natural orderings. I didn’t even argue whether an ordering can be given for an infinite multiverse. I noted that their response is interesting and potentially valuable for providing such natural orderings on infinite multiverses.

The point I made stands: if we cant find natural orderings for infinite multiverses, then we can’t meaningfully talk about the frequencies or proportions of universes within the multiverse. Their comment is germane to the antecedent (“if we can’t”). If they’re right, then we can indeed find natural orderings for infinite multiverses, so the consequent doesn’t necessarily apply.

1

HortenseAndI t1_jc9kdc8 wrote

Y'all are getting worked up about comparing countable infinities. There are other ways to have 'most' of an infinity - e.g. there are more non-rational reals than rationals because the former is uncountable

1

Seek_Equilibrium t1_jc9kzge wrote

You’re talking about cardinalities of infinite sets, which is not directly relevant to defining proportions or frequencies of the elements within an infinite set.

1

HortenseAndI t1_jc9t1yj wrote

I mention it because the relevant passage in the original article is "you cannot have “most” of infinity. The only scenario where it somewhat makes sense is where a finite number of worlds evolved life, but an infinite number did not.", which is blatantly untrue given that you can compare infinite sets with different cardinalities. My point is there's no need to get hung up on the probability space of countably infinite sets to comfortably assert that that's nonsense, which is what was happening here

1

python_hunter t1_jc80o1e wrote

I'm not sure that defining a 'sequence' is as relevant here as one might think; while it's a strategy often used in proofs, I don't think that (in my layperson's understanding) this precludes there existing different 'orders' of 'infinity'

0

DarkSkyKnight t1_jc68m1d wrote

Could just limit ourselves to the space of measurable sets. Seems like the natural approach since we're dealing with notions like "most" (almost), "frequent" (probability) here. And it doesn't seem immediately clear why we would need unmeasurable sets for the multiverse.

1

Azmisov OP t1_jc55o21 wrote

Interesting point about "most". I see how it works if you only consider a finite subset of integers (e.g. ratio restricted to < N), but is "most" still well defined if you consider the entire infinite sets together?

Physics isn't my expertise, so my understanding is surely off in some ways. My thinking was that we all exist in an uncollapsed superposition, but conscious observation is always with respect to a collapsed state. E.g. Each universe is a manifestation of a possible state in the overall multiverse superposition. You're saying though that the superpositions are never reduced, so would that mean no universe can be observed individually, only as a collective multiverse?

I admit it's not really a direct commentary on Many Worlds, but I do think the screenwriters began with the premise: "What kind of conflicts would characters encounter when facing a multiverse somewhat related to that of quantum mechanics?" Comparing to Dr Strange, they seem to have spent a lot more effort to inject philosophical comments and maintain a somewhat consistent ontology. I think Joy's and Waymond's character arcs only work when you include the metaphysical backdrop. They setup an initial conflict that nobody has free will, our universe is just a random possibility. Joy has lost her purpose in life from this fact and looks for Evalyn to try and convince her otherwise. Waymond's kindness speech to me was the revelation that the characters could still exert free will and "choose kindness" in every universe.

In any case, it got me thinking about metaphysics a bit more, so I'll take that as my personal interpretation of the film, even if it was only intended as a screwball film about family relationships.

1

SlightlyBadderBunny t1_jc5tumt wrote

> I do think the screenwriters began with the premise: "What kind of conflicts would characters encounter when facing a multiverse somewhat related to that of quantum mechanics?"

Why would you think that? It's very obviously a story about potential and familial expectation dressed up with pretty dope kung fu and silly men-in-black tropes to provide visual analogies to regular human interaction and emotions.

17

dolphin37 t1_jc6pse4 wrote

Yeah haha must admit I’m struggling with the over analysis here. I guess people are just excited to talk about multiple universes or something, which is fair enough.

The story seems like quite a straight forward love vs expectation one. Be thankful for what you have, not what you could or should have.

The science works enough to facilitate the plot if you don’t poke it too hard and that’s all you can ask for. Beyond that it’s just an incredibly stylistic, heartfelt movie.

2

Wuizel t1_jc69mpp wrote

I've seen this so many times and I never understand how you guys get to this conclusion. The initial conflict is that Joy needs her mother to see and love her in a way that she can feel. Joy has been traumatized and after seeing the reality of the misery of the worlds, have lost hope that human existence is worthy of her living in it. She still searches for an Evelyn among the worlds, one that can see and love her even though it's irrational based on her worldview because humans are irrational creatures and love is an irrational emotion. At the end, Evelyn acknowledges that nothing makes sense and the good moments are fleeting and not guaranteed, but stay around anyway because I'm choosing to stay for you.

Yes, Waymond is an influence in getting Evelyn to understand differing perspectives and that there are other ways of surviving than hers, but taking his approach she almost lets Joy go because that's what she asked her to do That's not where they end up though, and that's not presented as the "right" answer. At the end, she comes back, does explicitly the opposite of what Joy told her to do, tells Joy she's also been a bit of an ass, and pushes in the way that Evelyn has always done, but this time with a better pespective behind it.

This has always been a movie about the complicated relationship between immigrant mother and her daughter and the world they exist in, but for some reason, so many analysis of the movie comes back to Waymond has the answer, Waymond is right, they just needed to listen to Waymond. Well Waymond has been around in the family for the whole fucking time hasn't he??? But Waymond doesn't seem to have been able to address Joy's issues at all?? That doesn't mean he's wrong or responsible, but it does mean that I side eye all the people who wants to valorise Waymond while dismissing all of the rich dynamic and love and resentment and misunderstandings and story between Evelyn and Joy

6

gourmetprincipito t1_jc6fjgu wrote

I also saw the film the same way and am a little confused by all the focus on the multiverses. To me the film is an obvious interpretation of optimistic nihilism with the multiverse and Waymond representing nihilism and Evelyn and Joy making their own meaning with the freedom that allows.

1

platoprime t1_jc5diu4 wrote

>My thinking was that we all exist in an uncollapsed superposition, but conscious observation is always with respect to a collapsed state. E.g. Each universe is a manifestation of a possible state in the overall multiverse superposition. You're saying though that the superpositions are never reduced, so would that mean no universe can be observed individually, only as a collective multiverse?

None of that is correct. In many worlds theory there have always been and will always be the same number of universes. It's just that many of them look identical until they diverge.

5

Azmisov OP t1_jc5ltqr wrote

I didn't say the number of universes changes, so I don't know what you're commenting about

−10

dolphin37 t1_jc6wtqo wrote

I think the confusion is that you referred to wave function collapse, which is essentially the scientific term for our singular universe being all there is after said collapse being triggered by measurement. In MWI the collapse doesn’t happen, so you’re not observing that, you’re observing one of the probabilities of the universal wave function. I think that’s really what you meant but the terms weren’t quite right.

I also am unsure with if the person who responded to you is right anyway. My understanding of MWI is not that all universes already exist. The process is literally called branching. To say that we’re branching on existing paths, to me, means that we would need to assume free will and entropy are not ‘real’, otherwise at a particular entropic point, some universes only exist mathematically, which is not the point of MWI. Would be interested in having that one explained.

1

platoprime t1_jc7oshe wrote

>I also am unsure with if the person who responded to you is right anyway. My understanding of MWI is not that all universes already exist.

They "branch" because they were coherent and identical before that.

The alternative is to suggest every time a measurement occurs an entirely new universe is created. Where do you imagine the energy required to create an entire universe comes from?

1

dolphin37 t1_jc7xxvx wrote

(My understanding:) In MWI, the universe is the wave function and each branch dilutes the energy. So if you have 1x energy and the universe branches, each 'world' contains 0.5x energy. We don't notice the change in energy because our entire world has got proportionally skinnier. That happens as part of decoherence.

Is this maybe a confusion between terms or something? The wave function/universe is one thing, the many worlds of which are created 'in to'... that kind of implies there is a thing they are in though, which is not necessarily the case. We can describe it as some kind of gigantic dimensional configuration space but as far as I'm aware that's not posited as a physical reality.

1

platoprime t1_jc7zfpr wrote

When an electron is in a superposition of two states it's the sum of two states. When it collapses it collapses to a single state. What happens to the other state? Is it gone and we don't need to worry about it(Copenhagen). Do both states happen in their own universes(MWI)?

So it's not totally incorrect to say 1 becomes two .5s but where in that description is a new universe created? The two states always existed. It sounds like a split when you reduce it to .5+.5=1 but in the superposition both states exist so it's more like .5+.5=(.5+.5). 1 isn't being cleaved in half. It's decohering into it's two states.

1

platoprime t1_jc809rm wrote

Sorry to reply twice but I didn't want to edit my other comment in case you missed it.

>as some kind of gigantic dimensional configuration space but as far as I'm aware that's not posited as a physical reality.

It is actually. There aren't really multiple universes strictly speaking. Instead there is a universal wave function that describes the entire multiverse created by decoherence in our universe. That universal wave function is our universe.

I specify our universe because there are other theoretically possible sources of multiverses like eternal inflation or extensions to the Penrose diagrams of black holes.

1

dolphin37 t1_jc8mw1o wrote

Reddit broke so I lost my whole post, will try to be shorter now and cover your second comment too.

Yeah I understand the above but my point was that I don’t think MWI posits that our universe is anything more than the wave function. The wave function is not a physical massive dimensional space, it’s just what the universe is. The wave function exists in hilbert space but that is just a mathematical abstraction not a physical space. The many worlds are the physical spaces. They aren’t existing or expanding in to something more than themselves

Regarding your electron, the issue I’m trying to get to is the superposition of a given electron or even all electrons or even all fields doesn’t describe every state of the environment at all points of entropy and with all interactions accounted for. If one electron exists now and all worlds exist for its superposition (you said this but branching is based off decoherence which is environmental entanglement not just superposition) what happens to an electron made one minute from now?

I’m not aware of MWI saying anything about time/entropy not being fundamental so this needs to be accounted for. For this to be accounted for in your scenario, the many worlds need to account for every current interaction and every past or future interaction at once. That means every possible event of decoherence has its own world that all start at t=0, when the universe was fully unentangled and entropy has yet to take effect. That doesn’t work if you remove entropy and making it work sounds like entropy is being proposed as emergent.

I can probably link to a dozen videos of theoretical physicists referring to branching and how often it happens. Sean Carroll has a common example he gives of how every radioactive decay in our body branches it, over time. I’m aware that sometimes these terms are used as human ways of understanding these concepts - but that is what we are and I’m not quite getting what you’re saying the abstracted alternative is?

1

platoprime t1_jc8re8a wrote

>Yeah I understand the above but my point was that I don’t think MWI posits that our universe is anything more than the wave function

Yes that's what I was referring to when I mentioned the universal wave function.

> The wave function is not a physical massive dimensional space, it’s just what the universe is.

Are you suggesting our universe isn't a massive dimensional space? That waves don't propagate and exist in a dimensional space?

>They aren’t existing or expanding in to something more than themselves

Exactly. At no point is anything new created the wave function simply changes.

>what happens to an electron made one minute from now?

What do you mean? If there are two outcomes for that electron then it will be created in two universes and both outcomes will happen.

> That means every possible event of decoherence has its own world that all start at t=0, when the universe was fully unentangled and entropy has yet to take effect. That doesn’t work if you remove entropy and making it work sounds like entropy is being proposed as emergent.

Yes, but when did I suggest removing entropy?

>I’m not quite getting what you’re saying the abstracted alternative is?

The actual model instead of imagining a branching tree of multiverses which is not what MWI is. These are identical universes that are entangled and decohere. I'm not sure where you got the idea entanglement contradicts what I said or implies the creation of new universes. When two particles become entangled they do it through interaction not creation of particles.

1

dolphin37 t1_jc9txzg wrote

At t=0 there is no entanglement and entropy has not yet occurred right? Nothing has occurred. For lack of a better term, entropy then creates a sequential nature to events from that point. There being no entanglement means that there is no decoherence, which means there is no branching. So at the point in your suggestion that every single world must be created, no decoherence or branching is happening. No physicist I have ever heard says that all superpositions create branches by themselves, it’s when they entangle with another quantum system. As soon as entropy makes sequence 1 happen, the wave function changes and then it’s theoretically possible to predict the rest of the universe, although I still don’t think it makes physical sense for all variations to be created at that point but that is what it is.

The fact that the wave function has to evolve over time/entropy, means reality is evolving too i.e. branching. What you’re proposing would mean every world where this evolution is happening was already created at a point in time before any evolution has begun. That’s not making sense to me

Are you able to link me to any resource that says no branches are created beyond inception? I’m looking everywhere and I can’t find anybody saying it

Edit: notice the language you used about the electron, you said ‘if there are two outcomes’, the electron ‘will be’ created in two universes then outcomes ‘will happen’. If what you’re saying was correct the language should be that those universes already have been created and the interaction effectively already has happened because the wave function must have fully determined the life of the universe as the wave function is reality and all of reality has already been created according to you

1

platoprime t1_jccqlk0 wrote

We don't even know that there was a t=0 and if there was we don't know what it was like. It's ridiculous to make these assumptions about t=0. Also there was almost certainly entropy at t=0. Entropy is a property of system so unless the universe wasn't a system at t=0 it had a value for it's entropy.

>If what you’re saying was correct the language should be that those universes already have been

I said the electrons will be created not the universes. You need to read my comments more carefully and consider answering my questions. Repeatedly shoving the word branching into your comment doesn't show that universes are being created. You're arguing about physics using a third hand analogy and are fixating on the word branching because you don't understand what's happening. It's like two people(universes) holding hands(coherent) taking different paths(decohering). No new person was created the two people just followed the same path until the branch.

> interaction effectively already has happened because the wave function must have fully determined

Absolutely not. The wave function describes a "moment" of time and as that function changes time moves forward. All you're saying is "if we have the starting conditions of the universe we can calculate the future conditions". That's called determinism.

1

dolphin37 t1_jccrn9j wrote

I’ve already asked if you can link to anything that can explain what is happening as I’m not connecting with your attempts to explain it and I can’t find anybody saying what you’re saying. I just get overwhelmed with physicists talking about instances of branching occurring over time. I don’t really see that you are making any points that I haven’t responded to but perhaps I’m also just not understanding those. The only questions of yours I ignored were ones I commented on previously and I’m not resorting to telling you to read more carefully for failing to address half of my previous comment, so you can keep that kinda language to yourself.

I tell you what, I’ll ask Sean Carroll in a couple of weeks and will get him to explain his view. I’ll write back and link you his response then and maybe that will help me understand and help you explain it better.

Edit: Some of your post appeared after I responded, dunno if you edited but doesn’t matter. Just wanted to say I don’t know why you talk down to me with stuff like ‘that’s called determinism’, like yeah, I know, I literally used the word determined in the quote. You did the same thing before where you tell me my understanding of the full universe is wrong only to agree with me and tell me that’s what you said. It makes me view you as a lot less credible.

1

platoprime t1_jccw9ey wrote

Let me try again then. Do me a favor and stop thinking about t=0 or when the universal wave function was created or when entropy started. Or even entropy at all. All of that is a separate and irrelevant question.

I don't want to source every sentence but if I say anything in the following comment that you don't accept then I would be happy to source it.

In quantum mechanics we have things called states. You can add, or superpose, any states together as much as you want. It's similar to how you can just add up waves and their interference. This sum of two states is called the superposition. Eventually though something in a superposition of more than one state will eventually interact with something causing it to resolve to one of it's base states. Unfortunately we cannot determine which state the superposition will collapse into. We can only describe it probabilistically.

We need to explain why this is and what happened to the other states. One solution is the Many Worlds Interpretation. In MWI the other states of the superposition don't just disappear. Instead, in another universe, the superposition resolved to the "lost" state.

Now notice how I said we need to explain where the "lost" state went? Well we need to explain it because the state existed before the collapse and we want to know where it went. The collapse of the superposition does not create a new universe and it does not create a new state. Instead these two states decohered from one another. Nothing new is created.

1

dolphin37 t1_jcdej3i wrote

You’re just mostly describing the basics of QM. That’s not the issue here. The topic is MWI and when the other worlds start existing. I already understand why they need to. It’s disconcerting that you’re using the language of collapse when talking about MWI as the wave function doesn’t collapse in MWI but I can just assume you’re describing the observation of our branch of the wave function after decoherence.

What you need to explain is why all of the many worlds must exist, all of which will be identical copies until their own event of decoherence happens. Each of these, at a point in time, having the same wave function as there’s no entanglement? It needs to be clear why it cannot be the case that we start from a position of one world, which then upon an event of decoherence, creates two worlds. Both of these worlds exist in the same hilbert space as before, but they are now relatively ‘skinnier’.

So if you can explain why all worlds, which will ever feature every event of decoherence, always exist, in a succinct way, then I’ll put that to Sean as the point of debate and he can hopefully help me get it!

1

platoprime t1_jcdhl2g wrote

>Each of these, at a point in time, having the same wave function as there’s no entanglement?

They are each a part of the same universal wave function. Of course they are entangled. If you know the outcome in one universe you know the outcome in the other.

>Both of these worlds exist in the same hilbert space as before, but they are now relatively ‘skinnier’.

Yes when they decohere they are "smaller" than when they are together. Nothing new is created two things that were coherent became two things that are decoherent. A division of existing space is not the creation of new space.

>So if you can explain why all worlds, which will ever feature every event of decoherence, always exist, in a succinct way, then I’ll put that to Sean as the point of debate and he can hopefully help me get it!

You're saying yourself that one "thick" thing becomes two "thinner" things. That isn't the creation of anything.

>It’s disconcerting that you’re using the language of collapse when talking about MWI

The entire point of MWI is to explain collapse.

1

dolphin37 t1_jcdrbnz wrote

MWIs ‘explanation’ for collapse is that it doesn’t collapse. You’re just using the wrong language when referring to a collapse that’s all.

I’m still just not seeing anything that explains why all must exist at all times vs them beginning to exist only at a point in time. It’s just not intuitive to start from a position of a potentially infinite number of identical copies. I get why it’s neater from a conservation perspective because everything has its own energy already before docehering but I need to hear something that explains why that can’t be split at the moment of decoherence instead, with the pre-decohered state containing all of the energy within one world.

I think I’ll leave it here as if there were a clearer explanation for this it probably would have come out by now. But I at least understand the position so can ask the question.

1

platoprime t1_jcdzczr wrote

Sean Carrol explains why your objection about too many universes is "wrong headed" in his short article on why MWI is "probably correct". He uses the word "split" to describe what happens to two universes when there is an apparent collapse

>(“spin is up” + “spin is down” ; apparatus says “ready”) (1)

>[...]

>(spin is up ; apparatus says “up”) + (spin is down ; apparatus says “down”). (2)

>[...]

>We wouldn’t think of our pre-measurement state (1) as describing two different worlds; it’s just one world, in which the particle is in a superposition. But (2) has two worlds in it. The difference is that we can imagine undoing the superposition in (1) by carefully manipulating the particle, but in (2) the difference between the two branches has diffused into the environment and is lost there forever.

When you have a superposition of two states each state is it's own world.

>You’re just using the wrong language when referring to a collapse that’s all.

The only time I used the word collapse in the comment you're replying to is to say MWI's purpose is to explain apparent collapse. Saying it doesn't happen is still an explanation. You're getting tangled in the weeds with this one.

1

dolphin37 t1_jceuu3l wrote

Yes in that example you already have entanglement/decoherence in (2), at which point I’ve already said the multiple worlds must now exist. Sean’s language in that very article uses terms like ‘we expect the apparatus to become quickly entangled’ and ‘once our quantum superposition involves macroscopic systems’ and ‘proceed to evolve’ and ‘it is as if they have become distinct worlds’. They ‘come in to being’. They ‘occur’. All of the terminology implies the actions are happening over time.

Saying the possibility for all of the worlds is always there is not the same as saying all the worlds are always there. If that’s what is meant, the language should be clearer. Which I will find out.

And yes you were trying to explain ‘apparent collapse’ but you didn’t use that terminology, like the terminology Sean does in the article linked, you just described collapse multiple times, which isn’t happening. I was just pointing out that it’s not ideal and already stated what I assumed you meant, which is exactly what you apparently meant, but you are again doing the thing where you default to telling me I’m wrong when you actually completely agree with me but have an inability to accept your own fault. Kinda tiring tbh.

Edit: It just occurred to me that you said my objection is that there are too many universes. I didn’t realise you still don’t understand my point this far in 😩

1

platoprime t1_jchbtln wrote

> It’s just not intuitive to start from a position of a potentially infinite number of identical copies.

You did say this after all.

1

Giggalo_Joe t1_jc7393f wrote

You started with a statement you cannot prove. You cannot prove there an infinite number of universes.

1

Psychonominaut t1_jc5tt13 wrote

Would disagree with your last point only because we don't know how the brain works. What if our brains can implicitly understand and mediate quantum states? If that's the case, every iteration of "you" might be vastly different because every iteration has completely different quantum states of mind to deal with from birth to death. Our lives and our thoughts compound from birth, I find it hard to believe that in all the probable universes, the same me is doing the same thing. But then again, based on many worlds, there would be an infinite number that supposedly do the exact same things. There'd also be an infinite number where because of the countless changes in others and histories, you are not you, or you are the you that does everything but the things you do.

0

hughperman t1_jc5ytmo wrote

>What if our brains can implicitly understand and mediate quantum states?

Sorry but this is sci-fi brain thinking. We understand the brain plenty well enough to answer this specific idea. The brain is a physical object, based in reality like every other object. We understand its molecular, cellular function very well. It is composed of particles like every other object, which have quantum superpositions like every other particle in the universe. The complex emergent behavior of the brain is difficult to understand, yes, but that is not a license to apply quantum physics concepts at macroscopic levels.

If you want to allow some spooky quantum navigation by a "soul" of some sort, we need to acknowledge that we are not talking about any physics or scientific knowledge.

18

Psychonominaut t1_jc6cfg4 wrote

Physics will be and is increasingly being applied to biology and the brain, so it's not necessarily sci-fi thinking even though I think the idea of multiverse is sci-fi thinking since we can't prove it anyway. We know a lot about the brain for the past 300 or so years of research that has gone into it but who knows if that's a lot or nothing depending on the future of these disciplines - we've not scratched the surface of a lot of things, things that require huge interdisciplinary approaches and in some cases revolutionary thinking and engineering. The idea of quantum states being mediated by brains is a working hypothesis by some* physicists in an attempt to try and explain emergence. And I've used this example before but appropriating the idea of bit flips to brains/biology and even interactions across the universe, sure there'd be repetition, but repetition of exact same elements, evolutions, and histories? Can only see that as unlikely unless there truly is infinity "out there"; the chances of the same/similar things happening become close to zero but not zero (ever with infinity). And in the end, imo this whole thread is pretty speculative.

−1

PussyStapler t1_jc5o5ry wrote

>You can have "most" of infinity. For example, most whole numbers are not prime, and both of those sets are (the same size of) infinite. Still, the ratio of the number of primes to the number of non-primes below a certain value is small (and tends to zero as that value tends to infinity).

You chose an interesting example, because the ratio gets smaller as the limit gets larger, but when the limit is infinity, then the ratio becomes 1:1. The number of primes is the same as the number of non-primes. They correlate on a one-to-one correspondence (bijection).

Similar to the sum of 1+2+3+4+5+6+7..... gets bigger as n increases, but when n is infinity, the sum is -1/12.

Infinity breaks a lot of our expectations.

You may still have a point about it still is possible to have the "most of infinity," whatever that means, but your example doesn't work out. Just because something holds at really big values of n doesn't mean it holds for infinity.

−6

Ok_Tip5082 t1_jc5t5xg wrote

That said there are still different levels of infinity. The reals have a Lebesgue measure strictly greater than the rationals.

Also the "sum of 1..inf == -1/12" is not the case at all, the whole point of that example is to show how different contexts and definitions can have conflicting answers, similar to 0^0 or 1^(inf)

2

lwalker043 t1_jc61hvm wrote

i agree with your decision to bring lebesgue measure into the conversation of "most", but i dont think that's the best example since the rationals have lebesgue measure as well as cardinality less than the reals.

a better example may be the cantor set and the reals: they have the same cardinality and yet the cantor set is measure zero where of course the reals have infinite measure. i think it's simple and fair to say that if "life" universes make up something like the cantor set to the reals, you have a very solid interpretation of "most" universes not having life at all.

2

Ok_Tip5082 t1_jc6amn6 wrote

Yeah, you bring up some great points. Honestly I would want to go the opposite direction though and compare growth rates of functions, many classes of which tend to infinity but at vastly different rates.

I totally tried to get a better example but then went on a wiki binge and got lost around the page of hyperbolic growth which contrasts itself against exponential and logistic growth then found my way to robert miles again,....

2

ImOpAfLmao t1_jc7euoy wrote

Firstly you're wrong when you comment that bijection implies ratio is 1:1. A quick example is the two sets A = {0, 1, 2, 3...} and B = {0, 2, 4, 6..}. These sets form a bijection (a -> 2a, and b -> (1/2)b). The ratio of #s in B less than x over #s in A less than x for some x is (ceiling(x/2) / x). And so lim x-> inf of (ceiling(x/2) / x) = 1/2. So bijections don't imply ratio is 1:1.

Secondly, you're wrong about their example not working out. The ratio in their example does not become 1:1, the limit tends to 0. Quick explanation, simpler ways exist, but just for illustration:

From the prime number theorem, we know lim x-> inf of (pi(x)/(x / (log x)) = 1, where pi(x) counts the number of primes below x.

In this case we want to figure out what limit of the ratio of primes is to non primes below x, or lim x->inf of (pi(x)/(x - pi(x)). Dividing both numerator and denominator by (x/(log(x)), we have lim x-> inf of pi(x)/(x/(log(x)) / ((x - pi(x))/ (x / log(x)).

Quotient limit rule, so the numerator limit is 1 by prime number theorem, so we have it equivalent to 1 / (lim x-> inf of ((x - pi(x)) / (x / log(x))). So if we show the denominator limit goes to infinity, the entire limit is 0.

Bottom limit simplifies to lim x-> inf of x*log(x)/x - log(x) * pi(x)/x, the latter term goes to 1 by the prime number theorem, and thus the entire denominator limit is just lim x-> inf of (log(x) - 1) which goes to infinity, thus entire limit goes to 0.

0

ImNoAlbertFeinstein t1_jc56cfq wrote

do we really know, for sure, as a proof or otherwise ?

couldn't there be an unexpected super cluster of primes at some prrviously unknown lagrangian like focal region of extremely large numbers.. or maybe a rules change in the general ditrubution of primes as we get into relatively unexplored ranges of numbers..

−9

ImOpAfLmao t1_jc59oa6 wrote

Yes, look up the prime number theorem, and write out the limits

13

CantFindMyWallet t1_jc5qa3j wrote

Can always tell who has taken calc 2 and who hasn't in these conversations

4

OneRingtoToolThemAll t1_jc62tw7 wrote

Can always tell who has recently take calc 2 and who hasn't in these conversations... or continued to use calc 2 in their professions.

1