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What is it like to understand advanced mathematics?

252 points| maverick_iceman | 9 years ago |quora.com

92 comments

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[+] Smaug123|9 years ago|reply
One curious thing I've noticed after completing my master's degree in maths is that the jargon of maths sometimes lets mathematicians communicate with far fewer words than non-mathematicians. Irritatingly, I can't remember any off the top of my head, though I know I've experienced this a few times. Here are some contrived and ineffective examples, where I put context in [square brackets]:

- "To first order, [the intervention turned out badly]" - "Modulo [this error, everything is going fine]" - "[The situation is] symmetric on interchanging [me and you]" - "[They are in] the same class under the equiv. rel. of…"

[+] SatvikBeri|9 years ago|reply
I think this extends to jargon from scientific fields in general–e.g. "on the margin" from economics, "failure mode" from engineering, "significant" vs "substantial" (statistics), "system 1/system 2" (psychology), etc.
[+] tnecniv|9 years ago|reply
This phenomenon is just a facet of having a robust, shared vocabulary. Words can be shorthand for complex ideas. Knowing more words allows you to express intricate matters with ease. This fact is why in 1984 the regime is trying to shrink the dictionary and simplify the language.
[+] craftkiller|9 years ago|reply
The same is true of programming. I also can't remember specific exchanges off the top of my head but I know I've used "it's a FIFO" and "do a binary search" to refer to non-programming related tasks.
[+] bdastous|9 years ago|reply
Similar to your third example: "Without loss of generality, [ our argument can proceed with the following assumption... ]
[+] bhewes|9 years ago|reply
Same goes for the field I know well, Poetry.
[+] jessriedel|9 years ago|reply
Equivalence classes aren't just jargon, they really are an important nonobvious concept.
[+] unabst|9 years ago|reply
Bullet point #6 is worth emphasizing.

>biggest misconception that non-mathematicians have about how mathematicians work is that there is some mysterious mental faculty

Popular perception would have you believe that advanced math is like weight lifting, where you need the brain muscle to process it. This weight is measured in IQ, and above a certain measure you are a genius. Einstein is the champion, and so if "you're no Einstein" then you have a perfect excuse to be ignorant and incapable of any advanced topics in math.

Of course, the reality as it should be perceived is that any advanced scientific topic is more like a journey, and that it never truly gets more difficult. It just becomes more specific and hence technical. We just go deeper and deeper into the rabbit hole of our choosing. Unfortunately, with this view, there are no excuses in being bad at anything. It's more dedication and obsession.

And Einstein himself has rejected any notion of genius being quoted often as saying, "It's not that I'm so smart, it's just that I stay with problems longer."

Except, didn't work, because the former group has written the quote off the words of a genius.

[+] cdevs|9 years ago|reply
I like your answer because there is something strange about generalizing a group of people who have dug deep enough down that rabbit hole. Are there signs of a newbie "person A" to a field that they would have more potential to always take on a problem in a better way than "person b". What if einsteins work never involved mathematics and he wrote mysteries about a detective and from his books we could tell this person understands taking on problems and how to learn from failing etc,etc..
[+] chestervonwinch|9 years ago|reply
Neat answer; although, the bullet points come off a bit like mathematical horoscopes (perhaps because of the use of the second-person, "you"). I often wonder if mathematics would be more popular if the beauty of works by it's masters were more accessibly appreciable by those without the mastery, as it is, e.g., in the arts or music. Anyone can look at a painting, see a movie, or listen to Bach, and at least have an opinion - not true for any random person flipping through, say, a functional analysis book.
[+] erdevs|9 years ago|reply
We must remember the frame of reference for these works. The audience.

Most art, and certainly most paintings, movies, and most of Bach's work, is written for a general audience. Works of advanced, pure math however are written for a very specialized audience, purposefully.

This does not mean, though, that math cannot be written for a general audience and be understandable or even "beautiful". As an example, Cantor's diagnolization is understandable by a 10 year old. The profoundness of the question it asks is also understandable, as is its initially seemingly mind-bending inscrutability. What's more the solution and the logic of the proof are perfectly understandable and some of the easiest to understand explanations literally use a child's method of counting (mapping fingers to numbers). This is a beautiful work of math. And much math could be written for broader consumption. It's not done frequently only because that isn't the task most mathematicians set themselves to.

Moreover, even outside the actual proof, many math results can be described in understandable and even beautiful ways. And the derivative results of mathematical discoveries are often easy to describe, understand, and appreciate as impactful and beautiful.

So, I think this is a function of choice and focus. Perhaps math could indeed more popular if greater efforts were made here, but mathematicians as a group on the whole haven't set out to popularize it.

Now, no matter how much effort is applied, math will probably never quite be as enjoyable to most people as music or movies. But with such efforts math may be more appreciable to a wider audience, as say paintings or poetry are.

[+] chongli|9 years ago|reply
You are right that a lot of math is pretty inaccessible to the mainstream, but so is a lot of music. Sure, an average person can nod their head at the beauty of a Bach piece just as they might marvel at an (to them) unintelligible equation, but just as they do not understand the higher math they may also lack an understanding of counterpoint, canon in inversion, fugue, etc.

Likewise for avant garde cinema, modern art, poetry, and more!

[+] jordigh|9 years ago|reply
> A theoretical physicist friend likes to say, only partly in jest, that there should be books titled "______ for Mathematicians", where _____ is something generally believed to be difficult (quantum chemistry, general relativity, securities pricing, formal epistemology)

At least one of these does exist:

https://www.amazon.com/General-Relativity-Mathematicians-Gra...

Given how the author seems to be most familiar with geometry by the kind of examples that she or he gives, I'm surrpised that they're not already familiarw with this book.

[+] Koshkin|9 years ago|reply
It would be interesting to know what a book on advanced theoretical physics would look like if the author assumed that the intended reader already knows everything there is to know about the mathematics involved. In other words, what does theoretical physics minus math look like?
[+] freyr|9 years ago|reply
To some extent, this reminds me of Feynman's Lectures on Physics. The lectures were originally given to undergraduates at Caltech (so not "advanced theoretical physics"), but they rely more heavily on intuitive explanations than mathematical derivations compared to a conventional physics textbook. The books were highly regarded by physics experts, but were essentially a failure at their intended purpose of teaching undergrads and preparing them for future work.
[+] ivansavz|9 years ago|reply
Yeah, that would be amazing. I have a friend of mine who has a PhD in math, but has never learned any physics. Nevertheless, he was able to pick up some pretty advanced physics topics in a few weeks, to everyone's amazement.

On the other hand, perhaps the "math for physics" needs a different emphasis than general math-for-the-sake-of-math. E.g. perhaps for mathematicians certain topics are covered without much detail as they are relatively uninteresting, but a math-for-physics course would put extra emphasis on them because of some applications. Don't know enough to give concrete examples.

[+] myle|9 years ago|reply
Still quite interesting. Physics is a way of giving an interpretation to a physical system. Only based on an interpretation we can answer questions about internal and external consistency as well as completeness.

Trivial example:

a @ b

b @ c

c @ a

Makes "sense" if @ is = but not if @ is <.

[+] quantum_state|9 years ago|reply
As a theoretical physicist by training, I would say what remains would be the immutable facts about the physical world ... after all, math is only a language .. though very convenient n powerful one ...
[+] graycat|9 years ago|reply
> What is it like to understand advanced mathematics?

It's really nice! Get to understand a lot of stuff.

Some of the advanced math is really powerful for applications.

And, can look back at the math saw in physics where wondered if the physics profs really understood the math and conclude, right, they didn't or at least not very well.

E.g., recently I saw a physics lecture where they explained more than once that a quantum mechanics wave function was differentiable and "also continuous" as if there was some question, doubt, choice, or chance otherwise. Of COURSE it is continuous! Every differentiable function is continuous!

There's a lot more on why it's nice to understand the advanced math!

[+] smaddox|9 years ago|reply
> Every differentiable function is continuous!

Under who's definition? The Heaviside step function is discontinuous, but it's derivative is usually considered to be the Kronecker delta function. Both of these are used extensively in physics and engineering.

[+] Klockan3|9 years ago|reply
They most likely said "The wave function is differentiable and its derivative is continuous", which isn't obvious. If you think that it sounded strange you should have asked during the lecture and they would have explained. Now instead you just assumed that you knew better and made a fool of yourself...

Also this isn't advanced mathematics, this is something most who are interested learns in high-school and I can assure you that most physics professors are aware of this fact.

[+] ccvannorman|9 years ago|reply
Wow - This article made me think I identify with and act as a mathematician much more than I would've thought. I only started programming six years ago, but the way the author talks about breaking down problems, building frameworks and tool, and using multiple methods of attacks from an arsenal of knowledge that builds up over time, and how specific problems are not as interesting as insights into the general case -- these are all exactly the directions I find myself moving in as a programmer that just feel 'natural'.
[+] evincarofautumn|9 years ago|reply
Programming is undoubtedly the largest branch of applied mathematics—although for some reason we as a field don’t usually think of it as such.
[+] j-pb|9 years ago|reply
> your brain can quickly decide if a question is answerable by one of a few powerful general purpose "machines" (e.g., continuity arguments, the correspondences between geometric and algebraic objects, linear algebra, ways to reduce the infinite to the finite through various forms of compactness)

To me these tricks all feel like the same trick. "Can I find a program* that gives a finite representation of a generator or a transformation, from something I know, to my problem."

* Not as in php but as in lambda calculus.

[+] auggierose|9 years ago|reply
That's like saying each book ever written is based on the same trick, generating a finite number of words. True, but trivial.
[+] weinerk|9 years ago|reply
Thanks. Great read. Among other things this particularly resonated: You are easily annoyed by imprecision in talking about the quantitative or logical. This is mostly because you are trained to quickly think about counterexamples that make an imprecise claim seem obviously false. On the other hand, you are very comfortable with intentional imprecision or "hand-waving" in areas you know, because you know how to fill in the details.
[+] erdevs|9 years ago|reply
This is a great answer. It brings into relief many of the thought processes and experiences which change in tackling questions after studying advanced mathematics deeply.

However, the answer seems mostly to cover what it feels like to study tractable problems. Things like reading and understanding others' research or work, or studying new questions which seem "within reach, or nearly so." This is representative because this kind of work forms the majority for most mathematicians, and nearly all of the work for non-professional mathematicians who have studied math deeply and keep abreast of their fields, but don't research full-time.

One aspect of the experience of understanding advanced mathematics which doesn't seem to be covered thoroughly here is what it feels like to study truly intractable questions, let alone those questions which you fear may actually be inscrutable. The simultaneous awe, respect and consternation one feels when confronting truly difficult questions which you intuitively feel you just don't have the tools for. The problems which you think you'll need to discover new tools to even begin breaking down. This answer generally projects confidence and fluidity in tackling problems. And that's fair, in that this is the biggest change one undergoes when tackling mathematical questions after studying advanced mathematics deeply.

For deeper questions-- those which you feel you are very far from being able to answer-- the experience isn't quite opposite of what is described here, but it is different. When you feel that all of your fluid mappings and transformations, all of the most powerful tools at the ready in your toolbox, and all of your simpler analogues are not only not going to solve the problem, but are unlikely even to lead to a truly deeper understanding of it... when you're not even sure whether breaking the problem down in a particular way will be productive or counterproductive... when you've wrestled with a problem for days, weeks, and months and you're still not sure if the "foundations and frameworks" you've built are even of the right type or in the right vicinity to solve the problem... then the sense of confidence projected in this answer falls away. The sense of assured solution-- even assured understanding-- and fluidity of movement in problem solving is no more. You're still confident in your mathematical knowledge and ability, and certainly you feel differently than you did as a beginner. But it is a humbling experience.

The process of tackling these questions is not quite so structured as the impression that might be given by reading this answer. In these situations, Wiles' analogy of stumbling in the dark through a great mansion for months and years (which the author also quotes) is closer than the analogy given by the author of building a house. What even Wiles' analogy doesn't quite capture, at least in the section quoted here, is the uncertainty of the process of stumbling through that mansion. At various points you ask, "does this room even have a light switch? At least one that I can reach?" There is tremendous backtracking as well, rather than the sense of steady progression in discovering and understanding room after room. Imagine stumbling through the dark for weeks or months, finally discovering the lightswitch in a room... moving to the next room and doing the same... then on again to the next room to do the same again for yet more weeks and months... then only to discover, based on what you've seen in these rooms, that you must in fact be in the wrong hallway. Or the wrong wing. Or even the wrong mansion entirely.

In any case, I think this is a wonderfully insightful answer overall and its author deserves great credit for being so thorough, so accurate regarding the great majority of work, and so descriptive and relatable. I just wanted to enhance the picture painted here, or expand one little corner of it, as it relates to other types of experiences one is almost sure to have in understanding advanced mathematics and trying to apply that understanding to work in the field.

[+] ScottBurson|9 years ago|reply
Not a mathematician, but I have tilted at the P vs. NP windmill enough to have a sense of what you're talking about. It is indeed an awe-inspiring experience. I think I learned something by trying it (beyond the obvious lesson in humility, heh), but I'd be very hard put to say what that was.
[+] curiousgal|9 years ago|reply
>When trying to understand a new thing, you automatically focus on very simple examples that are easy to think about, and then you leverage intuition about the examples into more impressive insights.

Sounds like something Feynman would say.

[+] haruspex|9 years ago|reply
You get to explain the rules of the game set in one line:

"Pick 3 cards, such that for none of the properties exactly two are the same."

Not very advanced though.

[+] Smaug123|9 years ago|reply
Thank you for posting this example! I've used something like this myself to describe Set, but it didn't occur to me when I wrote my comment on the OP. The notion that one can quantify over properties (not just concrete objects) is one that is not necessarily obvious to someone without mathematical training.
[+] Chinjut|9 years ago|reply
Just as well, "Pick 3 points comprising a line (in the four dimensional space over the three element field)"
[+] cookiengineer|9 years ago|reply
Disclaimer: Contrary opinion that might not be yours

I'm building AIs and intelligent botnets for over 13 years now. One thing I learned is that I now think humans can't understand mathematics.

No matter how good you think you are, a simple AI algorithm will proof you wrong. From physics, to algorithms, to simulations, to automation, to analysis - and in evolutionary AIs also the solution generation for a problem.

Every single scientific mathematical model that occured in my life was in an "imperfect" state where humans think that our current "model of things" in form of mathematics is correct while it's totally incomplete and a few days of AI simulation figured out a better way to do it.

I somehow see mathematics not as a knowledge pool; more like a serialization format for transferring knowledge. And I think that serialization format often is too complicated for other humans to be understood and therefore has bias in interpretation and resulting conclusion errors.

And I personally think that this is a bad thing and a problem that needs to be fixed desperately.

[+] tgb|9 years ago|reply
> Every single scientific mathematical model that occured in my life was in an "imperfect" state where humans think that our current "model of things" in form of mathematics is correct while it's totally incomplete and a few days of AI simulation figured out a better way to do it.

I don't think I understand your claim and I'm rather skeptical of what you seem to be saying, so can you give three examples?

[+] jamez1|9 years ago|reply
An algorithm has limits that humans don't, as Godel's incompleteness theorems prove.

The study of mathematics is communicating some deep logic, but it doesn't end there as you trivialize. It's not just some poetry that we memorize, but it's a new insight to the nature of everything.

[+] DarkContinent|9 years ago|reply
This is a rather populist answer, but still pretty cool :)
[+] auvrw|9 years ago|reply
first, i recoil at "advanced" and would prefer "pure". that aside,

> You move easily among ... different ways of representing a problem

is like 3 answers in one. representation has specific meaning.

for me, however, it's not an ideal phrasing: i prefer not to think in terms of "problems". it can be productive to do so but also messy.

(as if i knew a/b math :p)

[+] tunesmith|9 years ago|reply
I don't know anything about architecture, but I know I dislike houses where it seems like the architect had just recently discovered the "extrude" tool and was picking all sorts of random things to pull out an extra three feet.