[DCKing]

The reasons presented in favor of a mathematical universe read somewhat like rehashed arguments used by deists/theists.

> For something to be physical it must be present at some time and place within the universe, and for something to be abstract it must exist outside of space and time.

No. He is redefining words here. 'Physical' is not usually defined as "exists in space and time". Abstract thoughts or concepts do not exist outside of space and time. Abstract thoughts are the results of the modeling capabilities of brains and exist very much in the physical world. It isn't even known whether "existing outside of space and time" is a coherent concept.

> but if the universe is a mathematical object, it needs no creator (on Platonism at least),

Firstly, this is the Kalam argument all over again. It isn't clear at all that the Universe needs a beginning or whether the 'beginning of the Universe' is a coherent concept at all.

Secondly, even assuming mathematical platonism is true, and even if 'creation' was a prerequisite for the universe, mathematical platonism has no construct to go from 'describing a universe' to 'creating a universe'. That seems to be quite an important thing to miss.

> Our universe is fine-tuned because it is one which has the ability to support conscious thought selected from an infinite multitude of mathematical structures, most of which are lifeless.

This is very problematic. Once you start thinking about "different mathematics", you lose all foundations upon which you can reason. Logic does not work anymore. Even if it were true at all, no human could possibly have meaningful thoughts about it. Besides, if we abandon the concept of our 'mathematical structures' in other universes, what do the words true and false itself even mean?

There's lots of handwaving with (very) incoherent concepts and dubious logic in this post to make the argument for a mathematical universe.

[zbyte64]

I agree with your points on Kalam but have to nitpick on everything else.

On the "describing reality" to "creating reality". Very few people argue for ex-nihilo creation but far more people tend to project that on the opposing side (ie where did god come from? what was before the big bang?). I don't think the author is arguing that mathematics allows for creating reality from nothing but that anything that resembles reality behaves mathematically and thus can transform into new situations with new mechanics (or realities).

Second nitpick: different mathematics. You don't loose the foundations of reason, rather you are stating that with different assumptions a system behaves differently. You are still computing the logical outcome with the premises given. If you have a universe where true and false mean the same then you have a very small universe that doesn't support any differentiation. Take comfort in knowing this helps solve Gödel’s incompleteness theorem. We can construct an infinite number of consistent mathematical realities but only by comparing their predictions to our reality can we resolve which reality is our own.

[DCKing]

> I don't think the author is arguing that mathematics allows for creating reality from nothing but that anything that resembles reality behaves mathematically and thus can transform into new situations with new mechanics (or realities).

I'm not sure I follow. What does "transform into new situations" really mean?

> We can construct an infinite number of consistent mathematical realities but only by comparing their predictions to our reality can we resolve which reality is our own.

If this is really what he meant, I appreciate the correction. If it would have been clear from the text, I would have proceeded with pointing out with pointing out the dodgy assumptions that underly the finetuning problem, but that would be even more like arguing against a deist/theist.

[zbyte64]

>I'm not sure I follow. What does "transform into new situations" really mean?

Emergence as a side-effect.

>If this is really what he meant, I appreciate the correction. If it would have been clear from the text, I would have proceeded with pointing out with pointing out the dodgy assumptions that underly the finetuning problem, but that would be even more like arguing against a deist/theist.

Yes, I am probably putting words in the author's mouth. He goes on a bit about computer simulations and how the Mandelbrot always "existed" because it is a mathematical consequence. In his view it seems different simulations are different universes and our universe is particularly amazing because it has evolved minds (computational constructs) that can distinguish different realities. Pair that with the idea that mathematics is a choice based on preconditions and you arrive at my statement.

[DCKing]

Talking about "side effects", "transformation" or "emergence" seems to assign properties to mathematics that I can't really wrap my head around. I thought that all we could be certain of when it comes to math is that it is a self-consistent set of axioms and rules. A set, of infinite size or not, that would be static and fixed.

[zbyte64]

A set is fixed but you have an infinite number of sets. We could imagine a (infinitely large) set that contains all primes. But how was that set constructed? To construct such a set an iterative process has to be continuously applied to the prior set. I consider this akin to emergence because physical processes act much the same way and result in novel configurations (sets).

[yongelee]

Concepts can indeed exist outside physical brain matter. Such as the concept of math. The idea that 1+1=2 does not need a physical human brain to exist. If humans never existed the concept of math would still exist "beyond space and time". Abstract thoughts cannot exist outside space and time for human comprehension but those same concepts do not need humans to exist.

[westoncb]

But the word 'concept' refers to something specifically human: it's a name we've given to a category of human mental activity. Particular concepts may /refer/ to things that would be there without humans—but the concept making the reference would not. The whole issue under discussion comes down to that distinction.

[DCKing]

I'd love to have some evidence that such things as 'concepts' and 'ideas' can exist independent of brains. You can't just assert it and make it so. All concepts and ideas I've ever heard of were the results of brains attempting to model or describe.

By the way, I'm not talking about physical human brains. I'm talking about any brain, which includes human brains, dolphin brains, computers, and whatever other modeling machines exist in the universe.

[goldenkey]

The thing is, the definition of a concept, is the axiom that it exists outside of human understanding. Concepts are informational objects. Anyhow, the question you really ask, is does information exist outside of conscious humanity. And it might not. It might just be an interpretation.

[DCKing]

> The thing is, the definition of a concept, is the axiom that it exists outside of human understanding.

I don't agree with that definition of a concept.

Idea = mental representation of an object, or a set of objects and their interactions.

Concept = generalization of an idea.

wherein 'mental' justifiably implicates the working of a brain. It is very much tied to what we call brain understanding. Sorry for taking this discussion to the definition of words.