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Shut up and calculate: an extreme mathematical universe

arxiv.org

51–60 of 191 posts

Re: Shut up and calculate: an extreme mathematical universe

#51

Earlier quoted context omitted.

Why wouldn't reality contain contradictions?

I mean in the logical sense. If reality could contain logical contradictions then that would mean reality isn't rule-based, which means unconstrained randomness, no information, no meaning, etc.

But the contradiction is in the mathematical model not reality. Even a totally random universe follows some kind of distribution, which can then be modelled (which is exactly what QM is).

Re: Shut up and calculate: an extreme mathematical universe

#52

Math works because reality works. Not the opposite. Reality is bigger than math. Math is just a tool that models reality.

On the contrary, reality works because reality cannot contain contradictions. But the set of possible structures without contradiction is a superset of what is physically realizable. And mathematics is just discovering and cataloging the set of structures without contradiction. So reality works because math works.

[deleted]

Re: Shut up and calculate: an extreme mathematical universe

#53
post #39

Earlier quoted context omitted.

Chaotic systems are only intractable if you measure the initial conditions with finite precision.

No, that is not true. Their intractability has absolutely nothing to do with the precision of measurement. Assume the initial condition with infinite precision and the further evolution of the system is still intractable. Ignoring the Heisenberg Uncertainty Principle for a moment and getting to the heart of chaos theory the problem is the production of information at a rate faster than any existant (and I believe, th…

> the universe does [predict]

But it does not.

Re: Shut up and calculate: an extreme mathematical universe

#54

It baffles me that people ignore the fact that they have subjectivity when making these claims. It makes a certain amount of sense since science itself aims to remove any taint of subjectivity in its practice, so folks who want to be thoroughly 'scientific' in other aspects of their lives (e.g. their personal philosophies of reality) carry over over this ideal. But it's also a contradiction since science scientific m…

I know of a nice argument against simulationism that I think applies here:

If simulated universes can be "real," then we're assuming that there's a mapping between patterns of electrons in a computer (or provable theorems, if you're brave enough), and the real universe they represent. (Say, interpreting two numbers that may be stored very far apart on the chip as the positions of two particles that are, in the universe, very close together.)

The problem that this introduces is that there are no well-motivated ways that we could decide which mappings are "real," and could be "lived in." For example, we might claim that the state of the simulation must be map-able in polynomial time to some charts and pictures that a human could interpret - but an inhabitant wouldn't care.

So, since all mappings are equally motivated as far as an inhabitant is concerned, allow me to choose one that maps this grain of sand to a universe the same as ours.

Well, there you go. Our world in a grain of sand.

Re: Shut up and calculate: an extreme mathematical universe

#55

Math works because reality works. Not the opposite. Reality is bigger than math. Math is just a tool that models reality.

On the contrary, reality works because reality cannot contain contradictions. But the set of possible structures without contradiction is a superset of what is physically realizable. And mathematics is just discovering and cataloging the set of structures without contradiction. So reality works because math works.

If in your math 2+2 does not give you 4 it's not reality that is wrong, but your math.

>So reality works because math works.

Reality is that the one that contains the structures not math. So what you said does not make sense.

Re: Shut up and calculate: an extreme mathematical universe

#56
I am a theoretical physicist and I think mathematics is just a tool. A language to describe concisely but always approximately what goes on out there in nature. A way to foramlize intuition and test it for logical inconsistencies. I personally think it is counter productive to focus so much on giving tools a deeper meaning. Sadly many a theoretical physicist seems to be drifting into that corner never to come back... The cure? Keep talking to your experimentalist friends. They usually keep their feet on the ground :-)

Re: Shut up and calculate: an extreme mathematical universe

#57

An interesting article addressing this from Sabine Hossenfender: http://backreaction.blogspot.in/2007/10/mathematical-univers... Her more recent article (review of Max Tegmark's book) also comments on the same subject: http://backreaction.blogspot.in/2017/11/book-review-max-tegm...

This (the universe is 'made' of math) seems to me like the most egregious error in the general outlook of contemporary scientifically-minded people—and one I made myself for many years. If you really consider the issue closely, you'll see it depends on not overlooking certain dark corners of it which you can sort of ignore and assume to not contain contradictions—but they're there! And once you see them, it's hard to…

Have you read the paper or the author's book? Because you're distilling a rather rich and refined argument down to a simplistic description. The author doesn't argue the universe is "made" of math.

Re: Shut up and calculate: an extreme mathematical universe

#59
post #30
post #23

Alright, why not go one step further and make Universe computational instead? (i.e. state is important in von Neumann-style instead of meaningless in classical math-style; or algorithms vs formulas)

Tegmark's Mathematical Universe Hypothesis (MUH) is actually pretty much a computational theory of the universe. It basically makes the assumption that there exists somewhere the simplest process imaginable: One that counts through and runs all mathematical formulas which includes all programs, which, in turn, includes all (computable) universes. This assumption explains why our universe is oddly complex: If all univ…

I didn't take Tegmark's argument to be a computational theory. I took it to be an inductive one based upon the trend of the physics over the last decades towards the more and more generified multiverse theories. Ultimately, you land on a model where all consistent mathematical representations of a reality exist. At that level of abstraction, there is no where to go: it is the limit of the induction. There's a rather satisfying sense of self-evidence about it, but that doesn't mean it's falsifiable or true.

IIRC there are no arguments about computation or what underlying medium(s) are involved, it seems like a separate question.

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