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Lessons I wish I had learned before teaching differential equations [pdf] (1997)

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Re: Lessons I wish I had learned before teaching differential equations [pdf] (1997)

#51
post #16
post #14

If when I started learning about calculus at 14/15 someone had explained why we were doing this it would have made it so much less confusing. Explaining in terms of speed/distance/acceleration seems to make complete sense now (one of several potential examples). However discussing a function and talking about splitting in into small (infinitesimal) strips of delta quantities and a list of equations / proofs made it c…

Physics doing the work of actually teaching math is a universal embarrassment to math departments. Or, well, it should be.

It's worse than that. I remember that when I was doing physics aged 14/15/16, they weren't allowed to assume that we were taking the maths course that included calculus, so while you could see these repeating patterns crop up (half-thing-squared, you say? How peculiar) they were effectively prevented from taking the time to explain it properly. It would have made things so much simpler.

Re: Lessons I wish I had learned before teaching differential equations [pdf] (1997)

#52

“Why is it that no one has undertaken the task of cleaning the Augean stables of elementary differential equations? I will hazard an answer: for the same reason why we see so little change anywhere today, whether in society, in politics, or in science“ I see a lot of parallels with the Physics department and I think the reason is much more depressing. Both fields embrace a sort of masochism and active desire to keep…

> Both fields embrace a sort of masochism and active desire to keep knowledge impenetrable b/c it acts as a mechanism to feed out the dummies. The system acts an an informal IQ test - that maintains the prestige of the departments. If you're pigheaded and clever enough to get through the masochistic torture is that their undergrad textbooks then you're probably pretty clever and so the prestige of the degrees is maintained.

I have been a on the mathematics faculty, including at some decent places, for almost 20 years. I have never met a single university mathematics teacher who thought this way. To the contrary, we are delighted when someone shows even a spark of interest or aptitude (hopefully both). Granted there are high bars for reaching professional competence, but that's intrinsic to the subject—and there is a welcoming place, in math probably more than in any physical science, for amateurs as well as professionals.

> As he observed, other departments will step in an do much better. The best linear algebra class I had was a graduate course in the electrical engineering department

It's worth noting that this isn't necessarily because EEs are better teachers—although of course in any particular case they might be—but because they can give you a course more focused on your interests. Math departments wind up teaching many courses populated largely, if not entirely, by non-math majors, and we cannot be discipline experts in every field of application in which students might be interested—nor, even if we were, could we simultaneously teach one course in a way that appealed simultaneously and particularly to the diverse applications needed by every student.

Re: Lessons I wish I had learned before teaching differential equations [pdf] (1997)

#53
Nearly every educator I've ever learned from has unconsciously insisted that learning material remain sterile, and never become as funny and opinionated as this essay. For most students, "learning" is outrageously boring until you get out of college (or into graduate school) and suddenly learn through essays and memoirs that what was presented to you for 12-16 years in a bone-dry format as established gospel truth was actually the life's work of sometimes dozens if not thousands of people, each of whom fought through their own careers, formed their own views on society, joked, married, divorced, died, squabbled, sniped, and felt immense passion for the subjects they ended up distilling into textbooks for us. Much of the information we learn as students was at the time of its discovery controversial in the extreme.

A few years ago I experienced a perfect example of this phenomenon in a glassblowing museum in Sandwich, Massachusetts. The museum takes visitors through the history of glassblowing in New England, mostly by static exhibits but also with live glassblowing demonstrations. At one point in the tour I read a placard that said something like "in 17XX, John Newenglishman invented a stamped glass method that allowed for much higher production rates of glass. The already-employed glassblowers resisted this development as it meant infringement on their industry." Then I looked up at the wall and read a quote from John Newenglishman that said something like "after demonstrating my stamped glass method, I hid in my room for weeks... gangs of blower-men hunted for me, no doubt to inform me by force their displeasure with my invention." I am paraphrasing in the extreme, but I was struck by how sanitized the placard was compared to the actual words of J.N. It reminded me of the history textbooks I used to read, which removed all of the flair and human-ness from the teaching of history.

If I could change one thing about modern education, I would somehow disabuse students of the notion that the development and archival of information has ever been "regimented" or "unbiased", and take great pains to expose them fully to the tremendous wit and wisdom of the past authors whose work they pore over. Anyway, great essay, saved.

(As a somewhat related point, I have also consistently found mathematicians and engineers to be much funnier than artists and authors, with the exception of artists and authors devoted to comedy. Somehow the tragic hilarity of writing math textbooks or working in a late stage engineering company never made its way into the material I was reading about math and engineering until I was out of my aerospace engineering degree by about three years.)

Re: Lessons I wish I had learned before teaching differential equations [pdf] (1997)

#54

“Why is it that no one has undertaken the task of cleaning the Augean stables of elementary differential equations? I will hazard an answer: for the same reason why we see so little change anywhere today, whether in society, in politics, or in science“ I see a lot of parallels with the Physics department and I think the reason is much more depressing. Both fields embrace a sort of masochism and active desire to keep…

There is nuance to this.

It's not so much a habit of being deliberately arcane as, in my opinion at least, badly attempting to keep the sense of the sublime that engineering departments often lose touch with.

I went to a pretty shit physics department, but there were glimpses of beauty. The engineering department was more professional, better run, definitely more fun if you like the thrill of actually making something, but as engineers theory is just a means to an end, so I would've been bored on some fundamental level.

Aside:

As a (I suspect) dyslexia diagnosis in-waiting I am a sucker for really good, crisp typesetting. Old books often struggle with that (e.g. particularly curly non-latin characters are almost unreadable for me), but reasoning is timeless.

Landau & Lifshitz is old, ugly, a bit terrifying, and yet timelessly brilliant. Difficult, but in a physically challenging way rather than the more modern, Grecian-thinking, rigour-by-nomenclature style found in modernity.

Re: Lessons I wish I had learned before teaching differential equations [pdf] (1997)

#55

Earlier quoted context omitted.

I quite strongly disagree with this. Mathematicians aren't rigourous just for the hell of it. We have examples where a lack of rigour caused a bunch of people to waste a bunch of time working of stuff that ultimately didn't work at all. For example the Italian school of algebraic geometry caused the waste of legitimately decades of work by many people because the foundations weren't right: https://en.wikipedia.org/wi…

On the other hand, if you want full and complete rigor that means formalizing things in a computer-based proof checker. Now, that can often reveal ways to refactor the argument into a cleaner, more elegant, more intuitive proof, which is why full formalizations are often regarded as publishable work - but the other side of it is that dotting all the i's and crossing all the t's does take a whole lot of effort since s…

I agree that some published proofs are not as clear as they're supposed to be, but I disagree that formalizing things in computer-based proof checkers is the way forward there. Computer proof checking is cool, but its an augment to what we already do and not not a substitute for it.

The purpose of a published paper is to explain things to other humans, while that of a computer formalization is to explain things to computers. Just as it is generally not easy for a computer to understand a published proof, it is usually not easy for other mathematicians to understand the code you feed to Lean or whatever.

The stuff you need to focus on to get a computer to accept your proof is usually quite different to the stuff you want to focus on when explaining things to colleagues. Roughly speaking we care about why you're doing things, while the computer cares about the intricacies of what you're doing.

Re: Lessons I wish I had learned before teaching differential equations [pdf] (1997)

#56

“Why is it that no one has undertaken the task of cleaning the Augean stables of elementary differential equations? I will hazard an answer: for the same reason why we see so little change anywhere today, whether in society, in politics, or in science“ I see a lot of parallels with the Physics department and I think the reason is much more depressing. Both fields embrace a sort of masochism and active desire to keep…

Just out of curiosity, what was that classical mechanics textbook?

Pretty sure it was An Introduction to Mechanics Kleppner, Kolenkow

The book was probably okay-ish, the point is that surely someone could have made some improvements in the past few decades

Re: Lessons I wish I had learned before teaching differential equations [pdf] (1997)

#57
post #52

“Why is it that no one has undertaken the task of cleaning the Augean stables of elementary differential equations? I will hazard an answer: for the same reason why we see so little change anywhere today, whether in society, in politics, or in science“ I see a lot of parallels with the Physics department and I think the reason is much more depressing. Both fields embrace a sort of masochism and active desire to keep…

> Both fields embrace a sort of masochism and active desire to keep knowledge impenetrable b/c it acts as a mechanism to feed out the dummies. The system acts an an informal IQ test - that maintains the prestige of the departments. If you're pigheaded and clever enough to get through the masochistic torture is that their undergrad textbooks then you're probably pretty clever and so the prestige of the degrees is main…

I don't think the line of thinking is directly "lets make this painful on purpose" but there is a sense of - everyone has to go through the same gauntlet and some people are just not cut out of math/physics/etc. It's just the way of the world. There is not direct desire to make the experience better/smoother/easier than it was your generation.

I don't know how it is in the Math department, but in Physics there is almost a sort of hazing that goes on, where some subjects are just known for how grueling they are and how you just have to go through it

"To the contrary, we are delighted when someone shows even a spark of interest or aptitude" Not to read too much into it, but this kinda hints at the problem. You're delighted at the students that have passed your IQ test. There is generally very little care given to the 70%+ of students that aren't making the cut. The true horror is how many students are in the class and not getting it. And the teachers are not freaking out

From my university experience (which was a while ago) it was abundantly clear that most students hate their math/physics classes, were bored out of their skulls and the teachers are only interested in the engaged students that are getting it.

What you should be "delighted" by is when you find a new way to explain something that resonates with most of the class

Re: Lessons I wish I had learned before teaching differential equations [pdf] (1997)

#58

Earlier quoted context omitted.

You have to have a pretty helpless attitude to blame someone else (teachers) on your inability to learn from a good textbook. How are you ever going to learn anything truly novel in the world if you always delegate teaching to a teacher?

I shouldn't need to read a 500page textbook to understand a class that a teacher has been 'teaching' for 20 years. He's there to give me an understanding of the subject. I have at least 5 classes each semester which are very technical and difficult, it's impossible for me to read a textbook on each while also reading a 20-30 page lab instruction each night, all written in a technical language which I barely understan…

"Technical and difficult": there are both important concepts and broad strokes that your teacher should be good at explaining, and important details that should be explored in a textbook because they need good pictures, data, editing etc. more than good explanations.

Taking a longer time than normal to learn a topic and prepare university exams might be a good alternative to burnout; or maybe your lifestyle and/or intellect are incompatible with studying.

Re: Lessons I wish I had learned before teaching differential equations [pdf] (1997)

#60

“Why is it that no one has undertaken the task of cleaning the Augean stables of elementary differential equations? I will hazard an answer: for the same reason why we see so little change anywhere today, whether in society, in politics, or in science“ I see a lot of parallels with the Physics department and I think the reason is much more depressing. Both fields embrace a sort of masochism and active desire to keep…

given the current political environment i think we should protect and promote old textbooks as much as possible. they’re lean, devoid of ceremony, makes no assumptions about race/gender/political orientation/socioeconomic status of the students as they work their way through the foundations of the subject. for a modern example of mumble jumble junk, with so much presuppositions about your intelligence, see the rust book[0]. it’s a tough book to study because it wastes so many words saying nothing at all. many people have used it yet rust lifetimes and borrow checker semantics is as arcane and elusive as the holy grail.

[0]: https://doc.rust-lang.org/stable/book/

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