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Re:Is math real? by nologic01 on Tuesday September 26, 2023 @02:03AM (#37655051)
> one view is that mathematics is a stiff and fixed set of rules and algorithms while the other view is that mathematics is flexible and our understanding of math comes from questioning of why mathematics functions so effectively

I havent read the book but this dichotomy is not an intrinsic feature of how people pursued mathematics historically.

The "stiffness" and excess focus on rigor and accuracy developed gradually over the 19th century because people were being loose canons - primarily around calculus.

Re:Is math real? by leetcodesucks on Tuesday September 26, 2023 @02:10AM (#37655087)
Its still not stiff enough. Mathematicians really ought to settle on a sound and coordinated syntax
Re:Is math real? by eru on Tuesday September 26, 2023 @02:15AM (#37655112)
Syntax is about the least of people's worries when they worry about 'mathematical rigor'.

Math is made for people to read and write, and they have different 'domain specific languages' for different parts of math.

Now what would be useful is a tool, perhaps something like a large language model, to automatically translate from the notation used in one area of math into another.

That can't be a fully mechanical procedure (hence the need for something flexible like an LLM), because it's part and parcel of human mathematics to abuse notation here and there in the name of ergonomics.

My personal pet peeve is defining a function like f(x) := x + 3, and then treating f(x) as the name of the function, instead of just f. But really, it's just a harmless abuse of notation when done by some humans to other humans.

Re:Is math real? by salutis on Tuesday September 26, 2023 @02:46AM (#37655343)
I do not think mixing up 'f(x)' and 'f' is harmless, given mathematics is all about clarity. In any quality text, 'f(x)' denotes the value of 'f' at 'x', and 'f' denotes the function 'f' itself. Also, speaking of notation, I wonder why you used ':=' instead of '=' to define 'f'. There is no computation going on, right?
Re:Is math real? by eru on Tuesday September 26, 2023 @03:13AM (#37655582)
Mixing up 'f' and 'f(x)' is mostly harmless in practice. The underlying principles are still clear enough. (And I say that as someone who would _really_ like to make that argument that people who mess this up are somehow unclear in their thinking. No, they are mostly fine.

Getting 'f' vs 'f(x)' right mostly is really important for programmers who deal with higher order functions in general all the time. Most mathematicians don't fall into that category.

You could say calculus deals with higher order functions, like the derivative. And that's a valid way to look at it. But most people get by just fine using special purpose notation for the derivative and not thinking about it as a function just like 'f'.)

I used := to emphasis that I am defining 'f' here, not just writing down any old equation. (Eg like like in the example "Find all functions f such that f(x + 1) = x * f (x).")

Though if you wanted to be pedantic about notation, I could have written that as with the x on the other side of the :=, like f := \x -> x + 3 (for Haskell inspired notation) or f := (x |-> x + 3) where |-> means the little arrow I draw by hand to denote a mapping when I'm writing math on a chalk board or piece of paper.

I'm not sure why := would denote a computation? At most you might want to use it to denote an assignment in a mutable context?

Re:Is math real? by xeonmc on Tuesday September 26, 2023 @03:22AM (#37655667)
> Getting 'f' vs 'f(x)' right mostly is really important for programmers who deal with higher order functions in general all the time. Most mathematicians don't fall into that category.

Operators and functionals?

Re:Is math real? by eru on Tuesday September 26, 2023 @09:17AM (#37658851)
It's usually clear from context what you mean, even if you work with operators and functionals.
Re:Is math real? by bheadmaster on Tuesday September 26, 2023 @03:25AM (#37655681)
> Getting 'f' vs 'f(x)' right mostly is important for programmers who deal with higher order functions in general all the time. Most mathematicians don't fall into that category

Mathematicians deal with higher order functions all the time, e.g. in functional analysis.

Re:Is math real? by mbork_pl on Tuesday September 26, 2023 @05:07AM (#37656463)
The amount of "cheating" (as in, notation/language abuse) in functional analysis is much worse than that. People routinely call points in L^2[0,1] "functions"... OTOH, I don't think it leads to serious problems.

OTOH, the lack of rigor is definitely one of the problems of contemporary math. Many years ago, when I was a student, I studied one paper, coauthored by 2 people - call them X and Y. X was a very established mathematician, Y was a relative newcomer. There was one (set-theoretical) argument I couldn't understand, so I asked Y (he was my advisor's friend) about it. He told me "yeah, X asked me this, too, and I told him to use Zorn's lemma, and after a moment of thinking, he said, Β«yeah, that would workΒ»". I'm not set theorist myself, but it smelled suspicious to me, so I asked another friend, who knew much more about set theory than me. He smiled and said "of course it's wrong, it's a very common mistake".

Had X and Y written out the argument more rigorously, we'd have one less published result with no correct proof...

And I have quite a few other anecdotes like this, unfortunately.

One professor at my former faculty once told how he approaches refereeing papers. "For the first 30 minutes, I try to prove the main result myself. If I don't succeed, I spend the next 30 minutes trying to find a counterexample. This way I write most reviews in half an hour."

A few years ago I coauthored a book about non-linear analysis. Quite a few quite interesting topics. One of the coauthors insisted on writing out proofs in detail and rigorously, and now we joke that our book is the first one where some (quite established and known in this field) theorems are proved correctly for the first time. (And that includes proofs with gaps/mistakes in both research papers and monographs, btw.)

Re:Is math real? by eru on Tuesday September 26, 2023 @09:19AM (#37658877)
Integration and differentiation are examples of higher order functions. And so are many things you can do to groups.

I specifically meant getting this is important for programmers who deal with higher order functions.

It is not so important for mathematicians who deal with higher order functions.

Mostly because the intended audience for their writings is smarter than a computer, and there's typically more context.

Re:Is math real? by red_trumpet on Tuesday September 26, 2023 @07:09AM (#37657537)
> Also, speaking of notation, I wonder why you used ':=' instead of '=' to define 'f'. There is no computation going on, right?

In math, := is typically used to denote a definition. Using equality (=) only makes sense if both sides of the equality sign already have a definition.

Re:Is math real? by eru on Tuesday September 26, 2023 @09:20AM (#37658892)
Well, to be fair, = is also very often used for definitions. And the reader has to figure out from context which meaning of = applies.
Re:Is math real? by chasd00 on Tuesday September 26, 2023 @09:59AM (#37659407)
> In math, := is typically used to denote a definition.

i mentioned this up-thread but is that why := is assignment in Pascal? Wasn't Pascal the main academic language there for a while?

Re:Is math real? by red_trumpet on Tuesday September 26, 2023 @10:19AM (#37659745)
Yeah, I think that has the same origin. Though I'm not sure if programming languages or maths came first. Apparently, for programming languages it appeared first in ALGOL in 1958[1].

Edit: On math.SE[2] someone claims that it's notation borrowed form programming. Someone else claims that it was introduced by Bourbaki, which might predate programming, as Bourbaki started publishing in the 1930s. However, I couldn't find any evidence of this from skimming a few Bourbaki PDFs.

[1] https://en.wikipedia.org/wiki/Assignment_(computer_science)

[2] https://math.stackexchange.com/a/25215/312406

Re:Is math real? by chasd00 on Tuesday September 26, 2023 @09:56AM (#37659375)
I agree but i'm by no means even remotely an expert. Mixing up f and f(x) seems pretty bad to me.

f = y+3 makes sense f(x) = y+3 does not make sense (at least to me), f(y) = y+3 makes sense however.

f(x) is a function of x correct? It's articulated as "f of x".

> I wonder why you used ':=' instead of '=' to define 'f'. There is no computation going on, right?

:= is assignment in Pascal iirc, maybe that's where it's coming from.

Re:Is math real? by eru on Tuesday September 26, 2023 @10:27PM (#37669123)
Something like 'f(x) = y + 3' can make perfect sense, depending on context.

For example, that could describe a constant function that doesn't depend on x, and y is a free variable that gets its value from context.

Or y could implicitly be a function of x. That happens a lot in calculus or physics.

Re:Is math real? by atoav on Tuesday September 26, 2023 @03:27AM (#37655695)
While I agree with the point you make, I think that syntax has a huge impact. Maybe not on mathematicians themselves, but I am certain that mathematical syntax has done more to scare people away from the field than the actual mathematical problems themselves.

For example the convention to use the greek alphabet for certain things. This is totally arbitrary and you could have also used emoticons instead (had they existed). But what this means is that the pupil, before tackling the meat of the mathematical problem has to accept that weird looking letter they have never seen for no real reason whatsoever.

And I say that as someone who can fluently read the greek alphabet.

Re:Is math real? by 4gotunameagain on Tuesday September 26, 2023 @04:17AM (#37656084)
It is not arbitrary, it is heritage. Apart from the fact that Greek was the de facto scientific language of the west (which is no longer the case), I think we can agree that the characters of a single alphabet are not enough for notation, especially given the fact that it is very useful to be able to discern different types of entities, e.g. constants from variables or vectors from matrices.

If we changed symbols now, it would create an even bigger mess. Because the people that learn the new symbols, could not read any textbook published before 0 A.D. (Anno Discombobuli)

Re:Is math real? by atoav on Tuesday September 26, 2023 @04:46AM (#37656305)
So you read my comment and thought: "That guy who can read the greek alphabet doesn't know there are historical roots for greek letters in mathematical notation".

Sure, back then when everybody who learned trigonometry had a classical education with ancient greek picking greek letters when the latin alphabet wouldn't do was a rational decision. It just hasn't aged well.

Re:Is math real? by 4gotunameagain on Tuesday September 26, 2023 @05:16AM (#37656544)
I'm just saying that changing the symbols will make things worse, not better.

Virtually all the textbooks use those symbols. Do you have a viable and better alternative to suggest or are you just complaining? And I didn't assume that you know or don't know something, I just wrote it down for the sake of the argument. We are not having a private conversation, we are contributing to a public discussion.

Re:Is math real? by necovek on Tuesday September 26, 2023 @06:23AM (#37657151)
That'd not what they said: they made a claim that a single alphabet is insufficient, and thus Greek makes as good a choice as it was used historically too (and allows easy differentiation).

Math also uses made up symbols specific to math a lot (integral, summations, arrows, operators...).

If you want to claim that Greek is the problem, how would you solve the problem of insufficient symbols?

Re:Is math real? by Turneyboy on Tuesday September 26, 2023 @09:13AM (#37658799)
There are simple practical reasons though. We don't do that to be fancy. There are simply not enough letters in the latin alphabet to not have common intersection in writing. We like to use the same letters for objects of the same type (like x,y for coordinates or i,j,k,l for indices) because that increases readability significantly. But it does mean that you run out quite quickly.

Adding another alphabet alleviates those issues somewhat but even with greek letters added in we still run into this issue somewhat commonly.

Re:Is math real? by eru on Tuesday September 26, 2023 @09:32AM (#37659054)
Well, you could use variable names longer than a single letter?
Re:Is math real? by the-smug-one on Tuesday September 26, 2023 @11:41AM (#37661003)
It's a trade-off between brevity and verbosity, some mathematics do that. Often longer variable names are in ALL-CAPS. Since ab = a*b, it's important to differentiate vars from multiplications.
Re:Is math real? by eru on Tuesday September 26, 2023 @10:25PM (#37669102)
Yes, it is. I just brought it up because it's an important factor when talking about the need for additional symbols.

Btw, even mathematicians don't mind writing out `sin` or `cos` or `ln` in their formulas. So they are certainly not completely averse to multiple letters.

Re:Is math real? by mindcrime on Tuesday September 26, 2023 @12:22PM (#37661622)
There are simply not enough letters in the latin alphabet to not have common intersection in writing.

Agreed. But yet... some of the approaches taken to deal with that can be wildly annoying. Actually, using the Greek letters is probably the best of the lot, since they are a completely different set of characters with known pronunciations.

OTOH, sometimes you'll see people use both upper-case and lower-case latin letters in the same problem, forcing you to read it in stilted language like "The derivative of Big X with respect to y, plus the integral of Little x ..." Aaarrgggh.[1]

And then you get the "stylized" letters, which are (mostly) just Latin letters, but have no obvious unique pronunciation or verbalization without going through contortions. I mean, what do you say for "𝔑" especially if there is also a "n" on the page? And who's even going to recognize these monstrosities unless you're already a mathematician: 𝔖, π”š, 𝖄? Aaarrggggghhh.

[1]: to be fair, you could have the same problem with mixed case of Greek letters, but I haven't seen that as a common problem. But maybe that's only because I'm not a mathematician. shrug

Re:Is math real? by eigenket on Tuesday September 26, 2023 @06:08AM (#37657012)
Syntax and notation is an incredibly minor "problem". We have much more significant (and interesting) stuff to deal with.

Judging maths on its syntax is like judging a poem or work of literature on its font. It really isn't a central thing.

Re:Is math real? by ahhfgshando6698 on Tuesday September 26, 2023 @03:52AM (#37655905)
This is going to be a classic "computer programmer wants math to be like computers and doesn't get it" kind of take, but In my view the problem of mathematical rigour (or lack thereof) has only become worse over the 20th century and we certainly did not resolve any of the underlying issues in a foundational sense or a practical sense. In a practical sense, it's become much worse and we have many more layers now. In a foundational sense, we succeeded in giving up because we learned that we can in some sense pick and choose whatever is most convenient for our line of research.

That's probably okay if we view mathematics in the way this book (I have not read it, going based on the description here) advocates, as a sort of toy for playing with arguments. And I'm certainly not saying Math should ever be viewed as an empirical discipline nor constrained by that kind of thinking. But I don't think I'm the only one that takes one look at things in the realm of say higher category theory and thinks it's mostly playing word and symbol manipulation games, and lacks any real mathematical content that could not be discovered at a lower and more understandable (and less likely to produce new research) level of abstraction.

I guess I've sort of betrayed that I am pretty firmly a platonist in that respect so make of that what you will.

Like I said, this is not an unusual opinion for a computer person to have and I'm sure it's fairly annoying to any pure mathematician at this point. But I think it's still fair if we want to understand what turns certain people off of pursuing mathematics further.

Re:Is math real? by bananaflag on Tuesday September 26, 2023 @05:49AM (#37656856)
This is a classical example of what happens when people give up on rigour:

https://en.wikipedia.org/wiki/Italian_school_of_algebraic_ge...

TL;DR: They started producing false results.

Note that this was not about capital-F Foundations of Mathematics like (arguably) the foundational crisis of math that had its origins in the 19th century, but rather about lowercase-f foundations of a particular field, in this case algebraic geometry.

Weil's foundations of AG in the eponymous 1946 book were horrible and messy but they solved the issue (even today there are a lot of celebrated results that can only be found as expressed in Weil's language) and later in the 1960s Grothendieck provided the elegant language of schemes in which people generally learn and research AG today, and which helped prove long-standing problems like the Weil conjectures and (to some degree) FLT. Category theory was, in this case, essential to proving theorems about "real mathematical content" like numbers and points.

Re:Is math real? by francasso on Tuesday September 26, 2023 @07:12AM (#37657568)
Is that really the case? I'm not an expert in AG, but I would imagine that any major result published in Weil's framework can either be trivially converted to schemes or it has been ported over by now
Re:Is math real? by jonathanstrange on Tuesday September 26, 2023 @07:30AM (#37657725)
I'm not a mathematician so anyone please correct me if I'm wrong, but isn't the point of category theory to provide abstractions so your proofs are very general and cover a lot at once? Of course, it needs to be very abstract to achieve that.
Re:Is math real? by reacweb on Tuesday September 26, 2023 @08:23AM (#37658234)
IMHO, in order to be able to speak about these subjects, we must either be a mathematician, or have read logicomix (http://www.logicomix.com). It is the easiest book to read. Another usefull one is https://en.wikipedia.org/wiki/G%C3%B6del,_Escher,_Bach
Re:Is math real? by throwoutway on Tuesday September 26, 2023 @08:44AM (#37658467)
IMHO, the book was too loose with the truth (even though it was purporting to write about mathematical truths). It's a work of fiction (beyond just filling the characters' words to each other), but that wasn't revealed until the end which left me sour. It pretending to be history right up until the end

GED isn't really related to this subject although it contains some of the same themes and characters

Re:Is math real? by crabbone on Tuesday September 26, 2023 @09:10AM (#37658760)
This subject actually doesn't belong in mathematics: it's philosophy of mathematics. I.e. no matter how much you study mathematics you will not be able to answer (or even attempt to answer) these questions because no mathematical tools or disciplines are designed for that.

I also believe that the emphasis on "rigor" here is misplaced. The argument isn't about whether mathematical rules are rigorous or not. The argument is about whether mathematics exists independent of mathematicians (and they discover it in a way how an astronomer peers into telescope and discovers new stars) vs mathematics being created by mathematicians' minds (similar to how an architect designs a building: there weren't one before, and now there's a concept of a new building with so many walls, floors, windows etc.)

I believe that mathematics is art, not science. I.e. mathematicians create new rules, they don't discover them. The whole argument to support this point would be too long to write it in a single post, but the general idea is that mathematics is a system that can easily describe counterfactual worlds. We use it to also describe our physical world because, of course, it can do that. But then asking the question about the "surprising effectiveness" is moot: we deliberately made it to be as effective as possible, so how is it so surprising that it is?

Re:Is math real? by AnimalMuppet on Tuesday September 26, 2023 @09:22AM (#37658917)
> The whole argument to support this point would be too long to write it in a single post, but the general idea is that mathematics is a system that can easily describe counterfactual worlds. We use it to also describe our physical world because, of course, it can do that. But then asking the question about the "surprising effectiveness" is moot: we deliberately made it to be as effective as possible, so how is it so surprising that it is?

The "surprising effectiveness" is, I think, one of three things. First, the surprise is that we can create mathematics that describes our physical world.

The second surprise is that, when we find out something new, it often takes the form of existing mathematics that we didn't design to describe the physical world. (Though, from your point of view, I suppose you could say that we created mathematics to describe everything that could be described by mathematics, and so it's not surprising that something was there to describe reality.)

The third surprise (maybe this is just a restatement of the first one) is that mathematics really describes the physical world. It's not that we find some math that describes it, and then we change the situation a little bit and we need to find some new math. The surprise is that the math describes what is going on so well that it applies to situations that we didn't know about when we devised the math that applied. That is, it's predictive, not just descriptive.

Re:Is math real? by crabbone on Tuesday September 26, 2023 @12:08PM (#37661419)
Well, the last one is a kind of surprise like... if you believe in real numbers, then there are some nonrepeating real numbers (pi is believed to be one of them) that embed all other real numbers. I mean, to someone unfamiliar with the concept it sound amazing and improbable that some number embeds all other numbers (all of which are infinite). But this is because we aren't used to dealing with infinite things.

Similarly, if mathematics is so powerful as to be able to describe any physical reality, it shouldn't be surprising that it can describe ours, no matter how complex and detailed.

Re:Is math real? by snarfy on Tuesday September 26, 2023 @10:41AM (#37660117)
All ideas are discoveries, not creations. The fact that anybody else can come up with the same idea lends credence to this. That's how ideas work - they are transcendental.
Re:Is math real? by crabbone on Tuesday September 26, 2023 @01:15PM (#37662555)
Your argument is similar in spirit to the claim that all, even infinite sets can have single element selected from to form a new set (so called "axiom of choice"). I.e. you equate the mere possibility of existence with a proof of existence (it's not a slur, there are a lot of mathematicians who do just that).

I don't see the reason to think that coincidentally arrived at ideas mean that ideas are discovered. We use the same framework, with the same rules. It's not unlikely that we'll create same ideas, because we use all the same rules, but the framework is so vast... it has so many rule combinations it's mind-boggling how would you think all ideas already exist in this framework.

More practically, we call an action a "discovery" when we (unbeknownst to us) faced the consequences of the phenomenon being discovered, but didn't know why we were facing them. An astronomer who finds a "new" star was ever so slightly influenced by that star's light, gravity etc. A marine biologist who discovers a new deep-water fish was ever so slightly affected by that fish through a complicated chain linking many different species through biosphere.

An artist drawing a new painting isn't discovering it in the same sense. She isn't interested in how an existing painting was connected to the consequences of her life or the lives of the whole human species. By selecting of all possible ways the paint can be laid down on canvas her particular way of doing that she creates something genuinely new, or as new as it can possibly be. It's counterproductive to label this activity "discovery" because then we lose an important distinction between the nature of the work of an astronomer and that of a painter (or a mathematician).

There are sculptors who'd jokingly say that they "discover" the statue in a stone slab. But they do so in a sarcastic kind of way, really (well, artists are weird and will make a lot of nonsense claims just to trigger non-artistic audience). But, deep down, nobody believes that they are searching and finding good images, melodies or novels. I cannot really imagine a mechanism through which I'd discover the answer writing to you. It's a lot easier to explain what i wrote by saying that I meant to write it.

Re:Is math real? by snarfy on Saturday September 30, 2023 @12:48AM (#37712833)
It's not my argument. It's actually a very old argument.

https://en.wikipedia.org/wiki/Theory_of_forms