Talk:Mathematical universe hypothesis

Theory?

While I find Tegmark's proposals intriguing, I dispute calling this one a "theory". It's more of a provacative proposal that future theories adopt a particular and controversial featureCH (talk) 21:44, 21 August 2005 (UTC)

Isn't this just one of those ideas that occurs to pretty much everyone independently at some time or another? At least to philosophy students or distracted physics undergrads.

I'm not sure what "feature" you are referring to. Tegmark's "everything" or UE is frequently discussed as a potential TOE (for example in "New Scientist" magazine http://space.mit.edu/home/tegmark/toe_frames.html or... http://scienceweek.com/2003/sc031031-1.htm). It appears to be a theory rather than a tautology (which it is sometimes derided as). Please elaborate on what you mean by "feature" and why it should not be referred to as a TOE. In the meantime I'm going to remove the "feature of" insertion.Joncolvin 07:24, 9 December 2006 (UTC)

Being non-falsifiable, this proposal would not even qualify as science, let alone as a theory of everything. It is perhaps a "theory of everything" in a philosophical sense, but not in a scientific sense. Intriguing and attractive as it is, there is no way that experiment could possibly shed any light on the matter and therefore it lies outside the realms of science. Robin S 01:06, 27 January 2007 (UTC)

An extremely positivist viewpoint, Robin. This theory does in fact make predictions: one such prediction is that physics will become more "mathematical" as it progresses deeper towards the ultimate TOE. To date this prediction has been successful. Tegmark does not pretend that his theory is science; it is metaphysics, but metaphysics of a predictive nature. It bridges science and philosophy in a similar manner to the anthropic principle. Joncolvin 05:44, 18 April 2007 (UTC)

The last point of criticism "is self-contradictory because one cannot subsume all possible (partly contradictory) mathematical structures into one structure" is the result of a misunderstanding and has no bearing. The Ultimate Ensemble is not "one structure" ... the parts have absolutely no relation to each other. —Preceding unsigned comment added by 58.179.98.125 (talk) 03:25, 1 March 2008 (UTC)

This is a wikipedia article, not a research paper. It correctly reports what criticisms other physicists have made---there is even a citation showing you where this criticism was made. Just as a matter of interest, however, if the different parts have absolutely no relation to each other, and we are "in" one part, then presumably you agree with the criticism that the proposal is unverifiable, since we could never find any empirical evidence of the existence of the other, absolutely unrelated, parts. Dark Formal (talk) 05:24, 2 March 2008 (UTC)

It is a "theory" in the philosophical sense: a reasoning mindset. Philosophical theories are not provable in the scientific sense, they work, or they don't. Rursus dixit. (^mbork³!) 21:13, 29 June 2010 (UTC)

It is much more than just a philosophical theory. I argue it is a scientific theory. If you study the articles written on the topic by M.T., you'll see that there is math that goes with it, and some ways are suggested to test aspects of the theory. --IO Device (talk) 23:43, 29 June 2010 (UTC)

Relation to Schmidhuber's ultimate ensemble

Apparently both Max Tegmark's ensemble and Jürgen Schmidhuber's ensemble of all computable universes were published in 1997. Their relation should probably be clarified. Discrepancy (talk) 20:50, 5 July 2008 (UTC)

Inadequate "Responses" section

The Criticisms section has three subsections. The first two are criticisms and the third is entitled "Responses". It's good to have a "Responses" subsection, but it needs to summarise Tegmark's answers to the two attacks. It's unsatisfactory just to point the reader to Tegmark's book as if the article was a teaser campaign. I suggest that somebody who has read the book gives a short precis here of the relevant arguments. Tommy Herbert (talk) 22:25, 11 December 2008 (UTC)

The theory is well defined if you write it this way

The "Criticisms" section says: "Some argue that the "set of all mathematical structures" is not well-defined."

The Kolmogorov_complexity of the universe is 0, but the Kolmogorov_complexity of any part of the universe is more than 0. This means that if the universe was able to be converted to a form the computer would take as input, and if zip files were better optimized, then the universe would compress to a 0 byte zip file. This does not mean it could be represented as 0s and 1s or as a file at all. It means there is no total information because it all balances to 0. Many things decrease Kolmogorov_complexity as they get bigger. For example, "all integers" has more integers than "all integers except 107 and 30", but the Kolmogorov_complexity of "all integers except 107 and 30" is bigger. Similarly, if the universe includes all math structures, then that is very simple to describe: The Kolmogorov_complexity of the universe is 0. Also, the Kolmogorov_complexity of nonexistance is 0, which means if Max Tegmark's theory is true, then the universe does not exist. Its simple. BenRayfield (talk) 19:19, 5 March 2010 (UTC)

Mathematical structures in the level-4 multiverse exist relative to other mathematical structures. What you're saying is that the KC of both existence and nonexistence is 0, and from that you're implying that existence==nonexistence, from which you imply nonexistence (this is a contradiction). I don't see the logic in your implications. --IO Device (talk) 03:19, 6 March 2010 (UTC)

The KC of nonexistence is 0? Nonexistence isn't a thing, so how can it have a KC?Joncolvin (talk) 02:04, 24 April 2010 (UTC)

Joke?

Tegmark is known to produce elaborate intellectual jokes one time in ten or so. Funny enough, a few of them gain some considerable serious interest despite being jokes. Is this one of them? Just consider the sound of "MUH" and possibly also "TOE"... Rursus dixit. (^mbork³!) 21:17, 29 June 2010 (UTC)

Are you kidding? You're practically defaming the man. MUH ain't a joke. Just consider the number of articles by him on the topic. --IO Device (talk) 23:41, 29 June 2010 (UTC)

Perhaps more of a Shaggy dog story than a joke. And who cares how many articles X writes about X's idea? What counts is how many articles other experts (not popular media like New Scientist) write about X's idea. 84.177.47.244 (talk) 19:33, 1 July 2010 (UTC)

Improving "Criticisms" Section

The paragraph summarizing the three-way debate (Hut-Alford-Tegmark [1]) is correct. It simply states the criticism made in section VI.A of that paper, in the paragraph beginning "Finally, the Fundamentalist describes himself as...". One way to improve this section of the WP article would be to also include summaries of the other criticisms made in that paper. And also criticisms from other papers. Dark Formal (talk) 22:08, 29 November 2010 (UTC)

The "three-way debate" is fictional! The paragraph summarizing it obviously implies it's a real life debate in which two critics (rather than the two characters portrayed by his coauthors) were criticizing MUH, when (in fact of fiction) all the characters were speaking generally. See WP:SYN.

It is not acceptable for the structure of this article to be the lead followed only by criticism subsections. For clarity, does this article include ANY criticism that WASN'T in Tegmark's own paper? I'd suggest rather than heaping on more criticism, a first step would be to include the ACTUAL citations to Tegmark, (rather than Tegmark's citations), and to include Tegmark's replies to those criticisms (or to drop whatever's too obscure).—Machine Elf 1735 (talk) 05:00, 30 November 2010 (UTC)

Dark Formal: I have no idea what you mean. It is not fictional, it is a real debate, in print. The three authors explicitly say in the Introduction that each of them is the advocate of one of the positions in the debate. The criticisms of MUH in the paper are direct and explicit: did you read paragraph I pointed you to? If you are so worried about WP:SYN then we can easily rewrite the summary in this WP article using quotes from the Hut-Alford-Tegmark ("HAT") paper. Do you want me to do that?
I don't understand what you are trying to say in your second point. When you say "does this article include ANY criticism that WASN'T in Tegmark's own paper?" what are you getting at, and what do you mean by "Tegmark's own paper"? Since the HAT paper contains some of the few explicit published critiques of MUH it seems entirely reasonable to summarize it here. Dark Formal (talk) 02:56, 1 December 2010 (UTC)

Yes, I did read it, that was the Math, Matter, or Mind ("HAT") abstract. That's not the article that I've been discussing however, (see below or the citations you reverted).

No, it is not a real debate. Having "divergent views" makes for a protracted discussion, not a "vigorous debate" with "forceful critics". I'll explain:

The coauthors are cooperating. They're working for a greater good.

If any one of them were to actually "win", it would defeat the express purpose, of cautioning non-physicists to be "wary of any claim that modern physics leads us to any particular resolution of this circularity".

So, that's just swell they're all looking out for one another, but:

The goal of a real debate is to win.

When you read the article I'm referring to, perhaps you'll agree that we do need to say where we got it WP:SAYWHEREYOUGOTIT I know I was more than a little annoyed to directed to wade through a bunch of (mostly unrelated) cites, some without page numbers, only to find all of it Tegmark's article.

So, if we're going to tell the reader what Tegmark said these other guys said, but you don't want his name repeated like a mantra, (fair enough, except for missing all the cites and assuming what? I'm some kind of Tegmark fanboy [cured]). I guess several criticisms could be consolidated into one section where it's made clear that Tegmark discusses them all in that particular article.

Here's what I had. I pushed Vilenkin out of this paragraph. If you think it's best, we can keep the part about Formalism (mathematics) and an axiomatic "Platonic ensemble" being "incompatible" per Gödel. However, Tegmark's spent a lot of time on that and his response is presumably not [curses foiled again]. If it's not a deal breaker for math, how is it a deal breaker for math + sassy math-based life forms? (i.e. might be too technical for non-mystics).

Tegmark, along with physicists Piet Hut and Mark Alford, coauthored a journal article in the format of a fictional debate which erupts between three characters who each approach physics from one angle, of either: Math, Matter, or Mind. In this Penrose triangle: Math explains Matter, Matter explains Mind, and Mind explains Math. The authors explain that their intention was to caution the non-physicist, to beware of any claim that modern physics leads to any particular resolution of this circularity.

I think WP:UNDUE is a concern; it can't just be shooting fish in a barrel without begging the question of Tegmark's responses and why they were relegated to a short paragraph at the bottom when the article is about his theory. I'm not game for trying to add replies myself, but I'd be satisfied with removing the POV visual cues introduced by section headers, (there's not that much text and there's no need for a subsection).

• Criticism

• Other criticism
• Response

I want to point out, that the abstract does not once mention ANY of it, but I did find some Level IV and "Mathematical Multiverse" discussion at the end of the article. Per WP:SYN, they're supposed to specifically address Mathematical universe hypothesis, but I think Level IV or "Mathematical Multiverse" will do in a pinch.

Here's the MMM ("HAT") abstract:

We discuss the nature of reality in the ontological context of Penrose's math-matter-mind triangle. The triangle suggests the circularity of the widespread view that math arises from the mind, the mind arises out of matter, and that matter can be explained in terms of math. Non-physicists should be wary of any claim that modern physics leads us to any particular resolution of this circularity, since even the sample of three theoretical physicists writing this paper hold three divergent views. Some physicists believe that current physics has already found the basic framework for a complete description of reality, and only has to fill in the details. Others suspect that no single framework, from physics or other sources, will ever capture reality. Yet others guess that reality might be approached arbitrarily closely by some form of future physics, but probably based on completely different frameworks. We will designate these three approaches as the fundamentalist, secular and mystic views of the world, as seen by practicing physicists. We present and contrast each of these views, which arguably form broad categories capturing most if not all interpretations of physics. We argue that this diversity in the physics community is more useful than an ontological monoculture, since it motivates physicists to tackle unsolved problems with a wide variety of approaches.

The general one-liners for each stereotype are:

1. current physics has already found the basic framework for a complete description of reality, and only has to fill in the details...
2. no single framework, from physics or other sources, will ever capture reality...
3. reality might be approached arbitrarily closely by some form of future physics, but probably based on completely different frameworks...

Tegmark is number 3, the mystic.

You say: if I'm "so worried about WP:SYN then we can easily rewrite the summary in this WP article using quotes from the Hut-Alford-Tegmark ("HAT") paper." By summary do you mean the "Description" section? Because the lead is not something you've been reverting. Generally, I'd like it better if you did something in addition to as opposed to instead of... Personally, I'd prefer that we make ( quite a few, if not all ) of that last set of reverted edits, and improve the article from that basis forward. Anyway, hopefully things will get cleared up if you take a good look through this article. It's the one that appears to be the source of the criticisms (which were used without attribution to Tegmark or his responses):

• The Mathematical Universe (http://arxiv.org/abs/0704.0646)

I explore physics implications of the External Reality Hypothesis (ERH) that there exists an external physical reality completely independent of us humans. I argue that with a sufficiently broad definition of mathematics, it implies the Mathematical Universe Hypothesis (MUH) that our physical world is an abstract mathematical structure. I discuss various implications of the ERH and MUH, ranging from standard physics topics like symmetries, irreducible representations, units, free parameters, randomness and initial conditions to broader issues like consciousness, parallel universes and Godel incompleteness. I hypothesize that only computable and decidable (in Godel's sense) structures exist, which alleviates the cosmological measure problem and help explain why our physical laws appear so simple. I also comment on the intimate relation between mathematical structures, computations, simulations and physical systems.

—Machine Elf 1735 (talk) 19:47, 1 December 2010 (UTC)