# Occam's razor, goddidit and the many-worlds theory **URL:** \ **Category:** In My Humble Opinion\ **Created:** [May 23, 2018, 6:50am UTC](https://boards.straightdope.com/t/occams-razor-goddidit-and-the-many-worlds-theory/814662 "2018-05-23T06:50:41Z")\ **Posts on this page:** 9\ **Page:** 2
**Author:** ![Inigo\_Montoya](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/inigo_montoya/32/124_2.png) [@Inigo\_Montoya](https://boards.straightdope.com/u/Inigo_Montoya)\ **Post date:** [May 25, 2018, 5:02pm UTC](https://boards.straightdope.com/t/occams-razor-goddidit-and-the-many-worlds-theory/814662/21 "2018-05-25T17:02:43Z")
> [@AskNott](#): > > Be careful, my friends, in using Occam’s Razor. Many users experience shaving rash and minor cuts. That assumes they’re not using Maslow’s Shaving Gel. ---
**Author:** ![PlaceboTarget](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/placebotarget/32/1073_2.png) [@PlaceboTarget](https://boards.straightdope.com/u/PlaceboTarget)\ **Post date:** [May 28, 2018, 9:37am UTC](https://boards.straightdope.com/t/occams-razor-goddidit-and-the-many-worlds-theory/814662/22 "2018-05-28T09:37:54Z")
I’ve always enjoyed philosophizing and wondered about the fundamental principles from which the universe emanates. I love logic and clarity. And since I’m not a scientist, I’ve used materials popularizing scientific theories and advances to understand how today’s thinkers view the universe. One of the first ideas I learned was that this universe can’t be the only one there is. We may live in the best of all possible worlds, but the notion that this world was the only one in existence somehow did not make sense. It was logical to assume that this universe was only one of many – very many. Scientists are supposed to describe how things go but when observing various phenomena or a certain course of action, one can’t refrain from asking why or how come. Scientists know the early universe was extremely hot. Another somewhat curious thing is that the expansion rate of that young universe was just enough to avoid the collapse in the early stage. The present universe shows a surprising homogeneity at a large scale, but there are local irregularities indicating the early universe had regions with different densities. There isn’t a single mathematical model of the early universe leading to the mature universe we observe today. This means a) either God has set the exact parameters of the initial universe and controlled its subsequent evolution very closely, or b) the universe is infinite spatially or there is an infinite number of universes actually. Linde built a mathematical model where an infinite number of universes could be generated. The quantum state of the early universe was heterogeneous with chaotic differences, where excitation was low, moderate, or high depending on the region. Different regions expanded differently during the inflationary period of the universe. Regions with high excitation expanded the most massively, leading to a chaotic inflationary process that caused the universe to be divided into a swarm of microuniverses. In Linde’s model there is an infinite number of such microuniverses and inflation across the macrouniverse continues forever. It is a multiuniverse with an eternal existence. Another model is Smolin’s theory, where black holes can lead to the birth of new universes governed by different but similar laws to those in the original universe. Another multiworld resulted when scientists assumed that the four-dimensional universe in Hartle and Hawking’s study showed a surface teeming with wormholes. This particular universe was a highly dense one, where quantum traits became the most consequential. Mathematical calculations starting from this dense universe whose surface supported wormholes led to a model with a parent universe and numerous children universes, where these wormholes connected a high number – probably infinite – of regions. Is there a reason why the number of possible universes should not be infinite? Probably not. Hugh Everett came up with a method to calculate the number of possible answers to a question formulated in the terms of quantum theory and arrived at the conclusion that this number is an infinite one. Our reality is thus as likely to exist as an infinite number of other realities. After concepts such as quantum decoherence or formulation of consistent histories were added, the number of possible realities was curtailed drastically but Dowker and Kent showed the number of possible worlds was still an infinite one. Scientists have calculated that the odds that a universe with the characteristics and structure we see today should exist are very small indeed. Either there should be some inner mechanism of self-organization or our universe is only one of an infinite number of worlds that somehow coexist. If I took off the ‘glasses’ that define me as a person, plus those defying me as a human being, and if I glanced at the universe to see what it really looks like, I would probably face an abyssal reality, the kind of which I wouldn’t bear to watch. What reality really looks like is a philosophical question, but English and philosophizing are two hobbies of mine, and the reason why I am relatively present on this forum. I will take a short break and return to answer some of the questions I have been asked here. ---
**Author:** ![DPRK](https://avatars.discourse-cdn.com/v4/letter/d/4491bb/32.png) [@DPRK](https://boards.straightdope.com/u/DPRK)\ **Post date:** [May 28, 2018, 10:24am UTC](https://boards.straightdope.com/t/occams-razor-goddidit-and-the-many-worlds-theory/814662/23 "2018-05-28T10:24:19Z")
If you are talking about the “many-worlds interpretation” of quantum mechanics, as opposed to some complicated cosmological issues, the only problem is the unfortunate and confusing sci-fi name. If you consider that all Schrödinger is saying is that a system’s state may be a linear combination of some distinct states, that should not seem so weird. ---
**Author:** ![PlaceboTarget](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/placebotarget/32/1073_2.png) [@PlaceboTarget](https://boards.straightdope.com/u/PlaceboTarget)\ **Post date:** [May 28, 2018, 11:26am UTC](https://boards.straightdope.com/t/occams-razor-goddidit-and-the-many-worlds-theory/814662/24 "2018-05-28T11:26:01Z")
> [@DPRK](#): > > If you are talking about the “many-worlds interpretation” of quantum mechanics, as opposed to some complicated cosmological issues, the only problem is the unfortunate and confusing sci-fi name. If you consider that all Schrödinger is saying is that a system’s state may be a linear combination of some distinct states, that should not seem so weird. I wrote this brief summary to show what a simple layman can go through. I am not sure every high school student learns about contemporary competing schools of thought in physics. Obviously the infinite number of universes in Linde’s model has nothing to do with the many worlds interpretation of quantum mechanics. The topic in the previous post was the idea of infinite worlds. I wanted to point out this ‘infinite’ number of universes is not my impression or contribution - it is the amount of possible worlds put forth by physicists and popularized by books and tv programs. And now I’ll finally try to answer some of the other questions (‘so help me God’). ---
**Author:** ![PlaceboTarget](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/placebotarget/32/1073_2.png) [@PlaceboTarget](https://boards.straightdope.com/u/PlaceboTarget)\ **Post date:** [May 28, 2018, 12:45pm UTC](https://boards.straightdope.com/t/occams-razor-goddidit-and-the-many-worlds-theory/814662/25 "2018-05-28T12:45:22Z")
> [@Hellestal](#): > > I’m not sure why you say this. It’s not actually known whether the MWI mandates an “infinite” number of universes. > > From literally [the first paragraph of the Wikipedia page](https://en.wikipedia.org/wiki/Many-worlds_interpretation): “In layman’s terms, the hypothesis states there is a very large— **perhaps infinite** [2]—number of universes, and everything that could possibly have happened in our past, but did not, has occurred in the past of some other universe or universes.” Emphasis added. The number of ‘infinite’ worlds is not my idea. I’ve come across with the ‘infinite’ number of worlds in books, articles and tv programs. This is what I’ve mentioned in the post above: > [@PlaceboTarget](#): > > Is there a reason why the number of possible universes should not be infinite? Probably not. Hugh Everett came up with a method to calculate the number of possible answers to a question formulated in the terms of quantum theory and arrived at the conclusion that this number is an infinite one. Our reality is thus as likely to exist as an infinite number of other realities. > > After concepts such as quantum decoherence or formulation of consistent histories were added, the number of possible realities was curtailed drastically but Dowker and Kent showed the number of possible worlds was still an infinite one. > > Another multiworld resulted when scientists assumed that the four-dimensional universe in Hartle and Hawking’s study showed a surface teeming with wormholes. This particular universe was a highly dense one, where quantum traits became the most consequential. Mathematical calculations starting from this dense universe whose surface supported wormholes led to a model with a parent universe and numerous children universes, where these wormholes connected a high number – probably infinite – of regions. > [@Hellestal](#): > > You need to consider what you mean by SIMPLICITY. If this sentence was address to me directly, then I can see a huge straw man here. Let’s have a look at the OP again: > [@PlaceboTarget](#): > > Occam’s razor is the problem-solving principle that when presented with competing hypothetical answers to a problem one should select the answer that makes the fewest assumptions. > > Atheists have often invoked Occam’s razor to explain God away and to argue that the scientific method is a more effective means than religion to understand reality. > > I myself nurture the same sentiment, which makes me feel quite uncomfortable whenever I come across with the many-worlds interpretation. In their attempt to understand the nature of reality and to put forth coherent theories that can explain how things work, physicists speculate on the existence multiple (probably infinite) simultaneous realities. I am aware that abusing Occam’s razor can lead to simplistic and inaccurate models, but at the same time I can’t escape the feeling that the many-worlds theory is a violation of this principle that parallels the goddidit attitude. There are two places where the notion of keeping it simple occurs. First it is alluded to in the definition of Occam’s razor, where the idea is that one should not overburden an explanation with unnecessary ASSUMPTIONS. And second, when I myself admit that Occam’s razor should not be abused because it can lead to simplistic models, the definition of ‘simplistic’ being ‘treating complex issues and problems as if they were much simpler than they really are. Thus, I think the OP clearly appeals to a rational discourse where complex issues are addressed adequately but without making unnecessary assumptions that would overburden a scientific model to the point where it could become as implausible as religious interpretations. > [@Hellestal](#): > > You still haven’t come to grips with what SIMPLICITY means. > > The consequences of literally every quantum interpretation are “far from simple”. The consequences of literally every advanced physics theory are “far from simple”. The three-body problem from Newtonian mechanics has consequences that are “far from simple”. > > **Complexity arises from simplicity.** > > Every sufficiently advanced collection of possible laws of physics will result in “consequences” that are as “far from simple” as it is possible to be. There is no closed-form solution to physics problems like the three-body problem. If you’re looking at a sun, a planet, and a moon, and you want to know the position of those three bodies a billion years from now, you’re going to have to deal with “consequences” that are extremely far from simple. You’re gonna have to computationally chug, chug, chug out the “consequences” of the problem, because there is no simple formula that exists that can jump you straight to the final solution. _Complexity arises from simplicity._ That’s not just true of QM. It’s true of practically everything that’s worth studying. You are right when focusing on the consequences. It is what you have named ‘computationally intensive implications’ in a previous post. I am not familiar with what this means, but I don’t think it is what I have in mind. You are not right when you invoke my problem with complexity. I don’t have a problem with complexity. I think I can recognize it well and I am aware of the way simple rules can lead to intricate complexity, such as fractals, which can often be encountered in nature. This is the reason why I never mention the contrast simple vs. complex. I think I’ve mentioned the contrast assumption vs fact. It seems to me that the many worlds interpretation of quantum mechanics resembles the goddidit attitude in that it relies on assumptions rather than facts. ---
**Author:** ![PlaceboTarget](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/placebotarget/32/1073_2.png) [@PlaceboTarget](https://boards.straightdope.com/u/PlaceboTarget)\ **Post date:** [May 28, 2018, 1:39pm UTC](https://boards.straightdope.com/t/occams-razor-goddidit-and-the-many-worlds-theory/814662/26 "2018-05-28T13:39:46Z")
> [@Hellestal](#): > > Consider the **particle horizon** , or cosmological horizon. Suppose you can travel away from the earth at near _c_ speeds, and eventually you get so far away, that you can’t make it back. Far enough away, and not even light will make it back. Space is expanding, so eventually you reach a point where no information returns, because the space expands more quickly than even the light can traverse the space. This horizon represents the edge of the observable universe. > > Now here’s the question: is it “simpler” to assume that everything beyond the particle horizon does not exist at all? After all, this stuff is totally non-observable. We will never see or interact with it again. A particle drops of the end of the map, and it’s fuckin gone, man, out of sight forever. > > So does that mean that’s it’s “simpler” to assume that everything past the horizon ceases to exist? Literally? Is that the theory you want to work with? Is that how you think the laws of physics work, that anything who travels sufficiently far from where you are currently observing no longer exists? > > No. Just no. > > We assume instead that physics works by simple _rules_, not by assuming a complicated process that POOFS things into non-existence the moment we can’t see them. Those simple rules might have “computationally intensive” implications, sure, and you can think of that computationally expensive process is somehow complex, but it’s _not_ complex in the way that we’re talking about when we’re talking about the rules. It would be a ridiculously more complex universe if everything past the horizon from where you happen to be currently standing just vanished from existence. Why is _your_ position special? What are the people on the edge looking at? Nothingness coming up to swallow them? …or rather, a picture very similar to what you’re looking at, where space gently recedes beyond what they can personally observe? Your thought experiment boils down to the idea of observable universe vs entire universe. What is the logic beyond accepting there is more to the universe than what we actually observe? The simplest answer is common sense. But common sense has become such a tricky and debatable concept that it may not seem adequate in a discussion regarding physics. Facts would make a stronger answer. And this is probably the reason why your thought experiment includes the initial particle traveling beyond the cosmological horizon. We have your particle to begin with, which is a ‘fact’ in your thought experiment. Why can’t we say it really vanishes once it goes beyond the cosmological horizon? Because there are more assumptions to make when claiming particles evaporate out of existence than when accepting the universe’s larger size and what we already know about light. This is the common sense that I have in mind. When a magician makes a rabbit disappear, we know the rabbit hasn’t actually vanished although we may never see it again. Prior experience tells us the rabbit should be concealed somehow somewhere. Believing a rabbit can completely dematerialize like that involves a lot of more assumptions than inferring that the rabbit has been concealed in ways that we’re not aware of. This is common sense. When a scientist finds a new specimen, he will declare a new species has been discovered. There would be more assumptions to make if he thought the species he had discovered only consisted of one member. Prior experience tells him this specimen is evidence for an entire species lurking in nature. Although he hasn’t seen any other animal of the species yet, it will be safe for the scientist to declare the discovery of an entire species. It is common sense. As you can see, I’m focusing on the idea borrowed from Occam’s razor that making fewer assumptions is the more advisable path to take and on common sense. Why common sense? Because Schrodinger made an appeal to our common sense when he devised his thought experiment with the cat that was supposed to be both death and alive if people accepted the Copenhagen interpretation where a particle exists in all states simultaneously until measured. Common sense tells us that a cat cannot be both dead and alive at the same time. Certain scientists came up with the idea that the cat could be dead in one universe and alive in another, concluding that reality consists of a plurality of universes where all possible occurrences exist simultaneously in distinct, separate worlds. This idea goes against common sense. The idea of alternate realities violates prior experience and knowledge. Plus, it requires assumptions the kind of which at least I am not willing to make. ---
**Author:** ![PlaceboTarget](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/placebotarget/32/1073_2.png) [@PlaceboTarget](https://boards.straightdope.com/u/PlaceboTarget)\ **Post date:** [May 28, 2018, 2:00pm UTC](https://boards.straightdope.com/t/occams-razor-goddidit-and-the-many-worlds-theory/814662/27 "2018-05-28T14:00:03Z")
> [@Hellestal](#): > > So when you use mathematics, it is to emphasize the really-realness of Reality. So your own use of math is okay. But when others use mathematics, it can be somehow “fraudulent” or “overblown” or “abused”. But where exactly is that line you’re drawing between the usefulness of math as a tool, and its fetishization? This a philosophical question related to theory of knowledge and more specifically what truth is. We all know there are various tests that certify some belief as being the truth, such as the correspondence truth test, coherence truth test, consensus truth test and pragmatic truth test. I respect mathematics and scientists but when it comes to such essential issue as the nature of reality I would not accept the multi words interpretation if it only made use of math without providing any shred of evidence or taking into consideration prior knowledge and experience. My common sense tells me there would be too many assumptions to make. I guess I need to mention what these overburdening assumptions are in my opinion. Okay, I will do it. But for now I will take a break. Thank you for your patience. ---
**Author:** ![Hellestal](https://avatars.discourse-cdn.com/v4/letter/h/3ab097/32.png) [@Hellestal](https://boards.straightdope.com/u/Hellestal)\ **Post date:** [May 30, 2018, 3:28am UTC](https://boards.straightdope.com/t/occams-razor-goddidit-and-the-many-worlds-theory/814662/28 "2018-05-30T03:28:25Z")
> [@PlaceboTarget](#): > > Your thought experiment boils down to the idea of observable universe vs entire universe. What is the logic beyond accepting there is more to the universe than what we actually observe? The simplest answer is common sense. This is the religious answer. The existence of god is “common sense”, according to the majority of people. It is the simplest answer, according to them. I’m afraid I must disagree with this argument. “Common sense” is insufficient on its own, because common sense is exactly the argument that leads directly to “goddidit”, as you describe the idea, in the overwhelming majority of the population. Your belief that “goddidit” is an insufficient explanation is not “common”, but rather a sharply minority view. > [@PlaceboTarget](#): > > We have your particle to begin with, which is a ‘fact’ in your thought experiment. Why can’t we say it really vanishes once it goes beyond the cosmological horizon? Because there are more assumptions to make when claiming particles evaporate out of existence than when accepting the universe’s larger size and what we already know about light. Yes. Exactly. There are more assumptions to make when claiming particles evaporate out of existence than when accepting the universe’s large size. That is exactly right. Likewise, an evolving quantum wavefunction has quite an enormous amount of information about the particle embedded into it. And exactly parallel to what you say: there are more assumptions to make when claiming all of these other possibilities evaporate out of existence than when accepting the universe’s larger size and what we already know about the evolution of the quantum wavefunction. If you accept this argument in one context, you really should accept it in the other. It is exactly parallel. > [@PlaceboTarget](#): > > This is the common sense that I have in mind. When a magician makes a rabbit disappear, we know the rabbit hasn’t actually vanished although we may never see it again. Prior experience tells us the rabbit should be concealed somehow somewhere. Believing a rabbit can completely dematerialize like that involves a lot of more assumptions than inferring that the rabbit has been concealed in ways that we’re not aware of. This is common sense. It is quite easy to imagine a world where the rabbit vanishes. You could program a computer game world where characters make rabbits vanish all the time. In such a world, the correct answer is to believe that rabbits can vanish, because they _do_ vanish. POOF. Right out of the game world. Or to put it another way: It would be absurdly easy to convince an uneducated human being from an H-G tribe with no exposure to any information outside their tribe that our technology was “magic”, and that we could make rabbits disappear with our dark voodoo. Look at the history of cargo cults, for the human capacity to mistake surface appearance with deeper meaning. I must maintain “common sense”, although an absolutely excellent starting point, is insufficient to tackle deeper issues. We need an _objective refinement_ of common sense. We need to start with common sense, and then build it into something logically robust, in order to avoid “goddidit”. For example, in our world under physics as we understand it, a disappearing rabbit is a violation of conservation of mass, which is a _big fucking deal_. > [@PlaceboTarget](#): > > As you can see, I’m focusing on the idea borrowed from Occam’s razor that making fewer assumptions is the more advisable path to take and on common sense. Why common sense? Because Schrodinger made an appeal to our common sense when he devised his thought experiment with the cat that was supposed to be both death and alive if people accepted the Copenhagen interpretation where a particle exists in all states simultaneously until measured. Common sense tells us that a cat cannot be both dead and alive at the same time. “Common sense” isn’t saying this. _You_ are saying this. _You_ are saying that this violates your own personal intuition of how the world works. This is in exactly the same way that people say that god is the simplest, common-sense answer with the fewest assumptions. The tension here isn’t between the idea and “common sense”. The tension here is between the idea and _your own personal comfort level_ with the idea. This is exactly the same argument that religious people offer against a world without god. And their “sense” in offering that argument is in fact “common”, because they are an outright majority. > [@PlaceboTarget](#): > > The idea of alternate realities violates prior experience All of quantum mechanics violated prior experience. Top to bottom, it didn’t fit the previous story human beings told ourselves about the world. This is true _regardless_ of which interpretation you might favor. So should we dump all of quantum mechanics, then? Because it doesn’t fit our prior experience? No A better answer is that _we should change our idea of how the world works_, when we learn something new that violates prior experience in a manner that can be replicated scientifically. As soon as we accept the fact that our prior experience was, quite simply, wrong about the quantum world – which is _our_ world, it’s worth keeping in mind – then the quicker we can start evaluating quantum explanations on their own terms. _All of them_ violate our prior experience. The question is which of our new explanations has the fewest assumptions. > [@PlaceboTarget](#): > > and knowledge. It violates our _knowledge_? Really? So then, you know exactly how quantum mechanics actually works? Because that’s what knowledge is. To have knowledge is to have “true, justified belief”. I don’t personally have any knowledge of which quantum interpretation is right. I don’t think you do, either. You are not in a position, I don’t believe, to say which quantum interpretations violate our “knowledge” and which don’t. I like the MWI myself, because it has the fewest assumptions, but only a bit more than I like some others, precisely because the situation is so hazy and because we have so _little_ knowledge of how things actually work. > [@PlaceboTarget](#): > > Plus, it requires assumptions the kind of which at least I am not willing to make. This is simply false, as a matter of fact, as previously noted. The only assumption the MWI makes is that the Schroedinger equation is quite sufficient on its own to describe reality. It is not the _assumptions_ of the MWI that you dislike, but the _implications_. The assumptions could not be simpler. Your disagreement with it is that its implications violate your personal notion of “common sense”, just as religious people believe that a world without god violates their own notions of “common sense”. I personally think we need something a little more hefty than common sense to balance which hypotheses we give more weight, and which less. ---
**Author:** ![Hellestal](https://avatars.discourse-cdn.com/v4/letter/h/3ab097/32.png) [@Hellestal](https://boards.straightdope.com/u/Hellestal)\ **Post date:** [May 30, 2018, 3:35am UTC](https://boards.straightdope.com/t/occams-razor-goddidit-and-the-many-worlds-theory/814662/29 "2018-05-30T03:35:15Z")
Re-reading that post, I’m not quite happy how I phrased a few things. I’m travelling right now (friend’s wedding) so less time for drafting, but will try to make future posts more clear than the previous. [Previous page](https://boards.straightdope.com/t/occams-razor-goddidit-and-the-many-worlds-theory/814662.md?page=1)