[HN Gopher] Ask HN: Concepts that clicked only years after you f...
___________________________________________________________________
Ask HN: Concepts that clicked only years after you first
encountered them?
I'm reading Petzold's _Code_ [1], and it dawned on me that I didn
't understand logic gates intuitively until now. I took a Computer
Architecture course back in college, and I understood what logic
gates meant in boolean algebra but not empirically. Petzold
clarified this for me by going from the empirical to the
theoretical using a lightbulb, a battery, wires, and relays (which
he introduces when he talks about the telegraph as a way to amplify
a signal). Another concept is the relationship between current,
voltage, and resistance. For example, I always failed to understand
why longer wires mean more resistance while thicker wires mean less
resistance. [1]: https://www.codehiddenlanguage.com/
Author : luuuzeta
Score : 256 points
Date : 2023-01-01 13:50 UTC (9 hours ago)
| nycdotnet wrote:
| I didn't really understand HTTP until I started using Fiddler
| which was probably 10 years after I had written my first web
| server application. "What do you mean I can't change the headers
| because they've already been sent?"
| ofcrpls wrote:
| Fourier Transform.
|
| I'd been writing DSP code in C and MATLAB during undergrad while
| thinking I knew every possible aspect thanks to the deep study we
| had as part of coursework across all the transforms methods in
| our ECA & Communications coursework in India. Also, dad was a
| self-taught hands-on Analog electronics whiz whose day job was in
| Telecommunications Training, and I had uncles and aunts in the
| Telecom/Electronics/ATC industry, so I had all these resources
| from a very young age to revisit the concepts that were being
| taught to me in school, against practical applications over and
| over.
|
| In week 2 or 3 of ECE490 at UofR, Prof. Heinzelman[1] broke a
| barrier that I did not know existed in my understanding of DSP.
| It was pinned to me realizing that the intuition between Fourier
| and Laplace transforms being the same. It was a moment that I
| haven't experienced since, in that I felt my brain got re-wired
| within that hour. It must help that her father[2] basically wrote
| the textbook on speech processing.
|
| [1] http://www.hajim.rochester.edu/ece/heinzelman/
|
| [2] https://www.ece.rutgers.edu/lawrence-rabiner
| bonzini wrote:
| Interesting, Fourier transform has never been an issue for me
| but Laplace never clicked. I know it's kind of similar
| (convolution, exponential and all that) but I miss the
| connection with the frequency domain that is there for Fourier.
| dannymi wrote:
| The frequency is the imaginary part of the Laplace parameter
| s (and the attenuation is the real part of the Laplace
| parameter s).
|
| Laplace transforms work on systems with attenuation--that's
| the main advantage.
|
| Because the kind of transform was swapped out anyway, people
| used the chance to often only define one-sided Laplace
| transforms that only work for t > 0 (because as an engineer,
| thats the systems you want anyway).
|
| There's a direct correspondence between the (usual) one-sided
| Laplace transform and the (unusual) one-sided Fourier
| transform for that reason.
|
| Since you usually have systems where f(t) = 0 for all t < 0
| anyway, the distinction one-sided or not is not so important
| in practice for understanding.
| ranting-moth wrote:
| Music theory. I'm not claiming I understand it all.
|
| I've had many eureka moments when I suddenly realise what or why
| this thing from years ago is important.
|
| I think teaching music theory with both _what_ and _why_ (with
| examples) is essential.
|
| I still have haven't found a book that does a good job of it and
| keeps it interesting. Any recommendations?
| criddell wrote:
| For me it was Microsoft's COM and how it's all powered by
| interfaces. It took a long time before it clicked for me.
| Fortunately, it didn't really matter because 20+ years later,
| it's still relevant. I've had plenty of time to work it out.
|
| The other Windows-related idea that took an embarrassingly long
| time to work out is device / printer / memory contexts.
| btrettel wrote:
| It took a couple years in college for me to understand entropy.
|
| Entropy in classical thermodynamics is presented in a mysterious
| way that leads to confusion.
|
| Entropy in statistical thermodynamics, however, is logical. Once
| one understands basic statistical thermodynamics, entropy isn't
| mysterious.
|
| The book in my statistical thermodynamics class was _An
| Introduction to Thermal Physics_ by Daniel Schroeder, which is an
| excellent book that I 've referred to many times since.
| luispauloml wrote:
| I had to study entropy twice in college for different courses
| that were 2 years apart from each other, and I still remember
| this one quote I read somewhere: The first time
| you study entropy, you won't understand it. The second time you
| study it, you'll think you understood it until you realize you
| didn't. By the third time you study it, you just don't care
| anymore and just use it.
|
| 10 years after graduating, and I haven't encontered entropy
| again after the second time, so you can guess where I'm at in
| this quote. But thank you, for now I know how to attack it if I
| ever need it again.
| btrettel wrote:
| Entropy is basically a useful quantity. It's no more
| mysterious than enthalpy or Gibbs free energy, both of which
| have also caused me confusion in the past.
|
| To me, the issue with entropy is that it's initially
| presented without clear justification, so people don't know
| _why_ it 's important. Statistical mechanics made it clear to
| me that the state with the most entropy is the most likely to
| occur in equilibrium. (Statements about entropy representing
| "disorder" and whatnot in my opinion are handwavy, often lead
| to confusion, and should be avoided.)
| atemerev wrote:
| I also have chosen entropy for my most memorable grokk! :)
| lambdatronics wrote:
| For me, it was approaching it from the information-theoretic
| perspective. E. T. Jaynes' paper was what made it all click for
| me: https://bayes.wustl.edu/etj/articles/theory.1.pdf
|
| Edit: but that was only after I had grokked Shannon's paper on
| information theory, which I felt was pretty intuitive.
| dplgk wrote:
| Steely Dan
| ilvez wrote:
| (got a smile out of me, both because the band name and original
| meaning) Do you mean whole discography? Because I really like
| their earlier stuff but lost interest at one point. Asking
| since if there was enlightenment with whole discography then I
| have more interest to take new dives.
| ilvez wrote:
| Actually skip the question .. I took their albums not
| linearly and got to Aja, so basically I already got nearly
| everything but have skipped few. Still a smile:)
|
| I thought they did more stuff on 80s..
| dudul wrote:
| A lot of the math I learned in high school didn't make any sense
| until I revisited it in college. The difference between stupidly
| copy/pasting rules and theorems without understanding them and
| having to demonstrate them from the ground up before being able
| to apply them made a humongous difference for me.
| TheAceOfHearts wrote:
| It felt like my understanding of pointers was a bit vague until I
| learned assembly. I think programmers would benefit from starting
| off with a simple virtual machine that runs a tiny set of
| instructions with everything presented cleanly in a visual format
| which can be inspected and stepped through.
|
| The biggest a-ha! moment I've experienced was in my Comptuer
| Architecture course when it finally clicked how you could build
| up a bunch of logic gates into a real modern computer.
| lakeshastina wrote:
| (1) Pointers
|
| (2) Recursion
| jmorenoamor wrote:
| Orbital mechanics. It was after playing KSP that I had that
| "woah! this makes sense!" moment.
| brunooliv wrote:
| The biggest one has to be design patterns in OO design!
|
| I was fortunate to have a great teacher which taught OOP by
| focusing on design patterns, dynamic dispatch, composition over
| inheritance, etc, etc, the really foundational concepts.
|
| I was too young and naive to fully understand all the concepts, I
| just thought writing Java was cool! Ah.
|
| Many years later, I really realized how to apply design patterns
| to solve real problems in a large production codebase and it all
| clicked then and in retrospect that teacher was really amazing, I
| just was too naive to realize it back then...
| ww520 wrote:
| Shader and OpenGL programming. It was many foreign jagons,
| concepts, and computation models. Took me a while and couple
| tries to get a hang of it.
| atentaten wrote:
| What were you trying that allowed you to get the hang of it?
| Also were there any online resources that helped?
| nkrisc wrote:
| Two concepts that I never really understood until I encountered
| them together: functional programming and recursion.
|
| When I first encountered recursive functions when I began
| learning programming I had a really hard time understanding what
| the function would do and how it would play out as it called
| itself. I couldn't think through the recursion and imagine what
| would happen. Nor did I really understand how to usefully apply
| one to a situation. I would either use a loop or a recursive
| function that utilized lots of external state to work.
|
| When I later encountered functional programming, having learned
| programming with OOP languages, it was a real mind-bender. I
| finally started to understand it but when I encountered the need
| for recursion in FP, it really threw me for a loop. How the hell
| was I supposed to do this without external state? So it was that
| restriction that really let me understand how to create a
| recursive function that could return something useful with
| nothing more than the initial input. This new understanding also
| gave me a better appreciation of functional programming and the
| idea of pure functions.
| sokoloff wrote:
| I had a similar experience with tail recursion that I only
| fully grokked much later when I had to implement some stack-
| trickery in C for a computer game. I realized then that tail
| recursion was typically optimized as a jump to code within the
| same stack frame rather than creating a new stack frame.
| abyesilyurt wrote:
| Specification vs Implementation: There could be only one
| specification, but many implementations. There is only one Python
| specification, but it has many implementations, cPython being the
| most popular.
| hydroid7 wrote:
| OOP on Java.
| a_c wrote:
| People never change because of YOU. This applies to work,
| relationship and family.
|
| It made me click about the saying that science advances one
| funeral at a time. It is easier to rally people of similar
| thought than to change people of opposite opinion. Not
| impossible, just more difficult. It explains a lot of thing in my
| opinion.
|
| 1. It is easier to start a start up than to convince your boss to
| take a certain product direction. E.g to not pursue certain
| pursuit, as outlined by John carmack's departure from meta. The
| ultimate judgement will be whether YOUR idea survive rather than
| whether your boss buy your idea. And I prefer bootstrap, at least
| for now, for that reason.
|
| 2. Never attempt to change your spouse. Find the common ground
| instead.
|
| 3. Empathy is mostly about experience sharing. You can't have
| people feel something they never experience before. If you can
| empathize, it means you have experience to draw similarity
| between. Imagine teaching a 18yo to be a father, that's how
| preaching people to be empathetic felt like.
| 99failures wrote:
| "The Innovator's Dilemma". I read the book and I took the class
| in b-school.
|
| At the moment I thought it was OK, fast forward a decade and it's
| one of the pillars of my business thinking.
| ttul wrote:
| When we think about history over any time scale, we tend to think
| about one region, person, group, etc within that period of time.
| In reality, "everything" was going on during that time.
|
| History is far richer than we tend to realize. So much is going
| on all the time; it's impossible to grasp it all.
| 23B1 wrote:
| Simple one: understanding probabilistic vs. deterministic
| thinking = the serenity prayer*
|
| The former is for dealing with any situation where we can't
| control the inputs and outputs. The latter is for when we can.
|
| *"Grant to us the serenity of mind to accept that which cannot be
| changed; courage to change that which can be changed, and wisdom
| to know the one from the other."
| jeffreyrogers wrote:
| Dynamic programming made very little sense to me when I first
| encountered it, then a few years later I read the DP section of
| Algorithms by Dasgupta, Papadimitriou, and Vazirani and it
| somehow clicked for me. Now I enjoy dynamic programming problems
| when I get them in interviews because they are usually pretty
| easy once you understand the trick.
| mesarvagya wrote:
| DP is just overlapping recursion with caching. That's it.
|
| Richard Bellman just wanted to give a fancy name for
| mathematical work he was doing without being suspected of
| it.[1]
|
| [1]https://en.wikipedia.org/wiki/Dynamic_programming#History
| sethammons wrote:
| This one is always interesting to me. People mention "dynamic
| programming" and my gut says "code that writes code" and every
| single time I remind myself it is just caching earlier
| calculations. DP is just caching.
| mumblemumble wrote:
| The monitor model in second language acquisition. Or, more
| accurately, the more contemporary synthesis that it's developed
| into in the decades since it was first proposed.
|
| The model itself is easy enough to grasp. But concretely
| understanding what it implies about how I should be studying took
| much, much longer.
| igammarays wrote:
| Very intriguing! Any links you can share on this theory? A
| quick Google search gave me an overview, but I don't see how
| this is particularly useful for second language acquisition.
| mumblemumble wrote:
| The big take-away is that explicit study of grammar rules,
| and even vocabulary to some extent, is kind of a waste of
| time. They encode information in a format and region of the
| brain that generally isn't accessible to the areas that are
| used in fluent communication.
|
| The way our brains have evolved to build up a functional
| language model is by observing lots and lots (and lots) of
| examples of the language being used for communication. Which
| implies that, even from the very beginning, graded readers,
| level-appropriate dialogues, etc. should be the foundation of
| a language study program and not, as most language
| instruction courses and apps make it, just a little bit of
| icing on top.
|
| The primacy of input is also kind of a big deal, and, at
| least for me, it took a long time before I was willing to let
| go of forced production exercises such as "translate this
| sentence into your target language". Perhaps in part because
| they're so endemic to language learning resources. You can't
| abandon them without also abandoning Duolingo and most formal
| classroom programs. But the problem with these kind of
| practice exercises is, we now know that it's normal for there
| to be a long delay between when someone can comprehend a
| grammatical structure, and when they can use it in a natural
| setting. (Anyone with kids over a certain age should be
| familiar with the phenomenon.) Forced production relies on -
| and reinforces - that aforementioned misplaced encoding, and
| there's a mountain of research demonstrating that skill in
| performing those sorts of exercises simply doesn't correlate
| with the development of communicative fluency.
|
| Tangentially, the transformer architecture that's taken
| natural language processing by storm has some interesting
| similarities to the leading model among SLA researchers for
| how language is represented in the human brain. Which isn't
| the monitor model itself, but might hint at a mechanism for a
| few parts of the model. Acquisition order, for example.
| djmips wrote:
| Given you eureka moment, besides what you didn't do (as you
| outlined), what did you do to increase your second language
| real world examples with feedback? Did you try immersion?
| mumblemumble wrote:
| "Immersion" is a tricky word that I don't feel
| comfortable using without qualification.
|
| What I like to do is spend at least an hour a day
| reading, listening to podcasts and audiobooks, or
| watching videos. A good day for me is a day when 100% of
| my media consumption for entertainment purposes is
| happening in my target language.
|
| And that really is it.
|
| I don't really bother soliciting explicit feedback. I
| suspect that it's potentially harmful because it can
| trigger the affective monitor. I've also encountered some
| SLA researchers saying the research indicates that it's
| not actually helpful. I'm becoming increasingly enamored
| of Bill VanPatten's conceit that, in a language learning
| context, there's no such thing as errors, there are only
| differences between the learner's interlanguage and their
| target language. Which is something that should be
| embraced as a natural and essential part of the process
| rather than a problem that needs explicit correction.
|
| So what I do instead is just pay attention to whether
| successful communication has happened. When getting
| input, that means I'm focused on whether I understood the
| content or not. I want it to be a little bit difficult,
| enough so that I'm not getting bored, but not so
| difficult that I feel I'm really straining to comprehend.
| (There's nothing scientific to that, it's just personal
| taste.) When I'm having a conversation with somebody, I'm
| just interested in whether or not I am having a
| successful interaction. In a sense, what I'm trying to do
| is set up a feedback loop that optimizes for pure
| enjoyment, which, for me, seems to be a very good proxy
| for learning effectiveness.
|
| To that end, I don't really intend to shit on Duolingo
| and practice exercises and whatnot. A lot of people enjoy
| those approaches to language learning, and the single
| most important thing is that you enjoy what you're doing.
| pcurve wrote:
| object oriented programming, with public, private, classes.
| inheritance, parameters... ugh. It took much longer to
| internalize these than I'd care to admit.
| samhuk wrote:
| Computer networks. For years I was dumbfounded how IP addresses,
| VPN, ports, etc, all worked and tied together. Then, when I was
| interning as a software developer a fair while ago, a colleague
| drew the analogy of "IP address" = house on street, "port" =
| something you ask for when you knock on the door of a house.
|
| Then it all just clicked. I still remember that day all these
| years later.
|
| Other notable mentions, in no particular order:
|
| * Perfect is the enemy of good enough. Did n't really appreciate
| this idea until around 2 years into my career.
|
| * How to be professionally displeased at something. Early on my
| career I would get way too angry at incompetent colleagues peeing
| in the pool, e.g. bad code, design, management, etc. I would
| complain quite a bit! It only clicked ~2-3 years later into my
| career when I figured that one's displeasure at a situation
| should be a function of _both_ how bad the situation is _and_ how
| able you are to improve it. When you offer constructive solutions
| to incompetence (suggest alternative algo, management style,
| library, tool, etc) whilst not actually mentioning what is wrong,
| instead of just fruitlessly reminding people of what they did
| wrong, people become far more cooperative and receptive, etc.
|
| My tin-foil-hat pet-theory is that the relatively recent tyranny
| of low expectations and "participation award" society has on
| average made younger people much more sensitive to negative
| comments about their work. The extension of that is that people
| end up robbed of more detailed reasoning about what they did that
| was wrong.
|
| People are interesting!
| wellthisisgreat wrote:
| > Then, when I was interning as a software developer a fair
| while ago, a colleague drew the analogy of "IP address" = house
| on street, "port" = something you ask for when you knock on the
| door of a house.
|
| Hey thanks for sharing! Can you maybe expand on this in any
| form? I'd love to get that kind of analogy. Maybe you have a
| blog post about it? That'd be amazing!
| [deleted]
| ruune wrote:
| This[0] blog post explains the basics of IPs, ports, etc.
| using that analogy
|
| [0] http://www.steves-internet-guide.com/tcpip-ports-sockets/
| ruune wrote:
| I've heard it with a door for every port, but one door where
| you ask for that specific port works too!
| layer8 wrote:
| I think "door" works better because any function can be
| behind any port, and it is a matter of convention, not of
| asking for a specific thing. I.e. when you connect to port 80
| you don't ask for HTTP, you just hope that's what's available
| at that port.
| darawk wrote:
| Tensors. Years ago, I would read the Wikipedia page about them
| every so often, and completely fail to understand what they were.
|
| Then one day I was modeling something in a spreadsheet, and I
| thought to myself "you know, what I really need here, is 3rd axis
| to this spreadsheet". And for a few minutes, I thought I had
| invented a new form of spreadsheet/structure, and was considering
| trying to build a 3d spreadsheet program.
|
| But, of course, suddenly everything I'd read about tensors and
| not understood before snapped into place, and I realized that
| this is exactly what they are (to be precise, this is a special
| case of a tensor, the contemplation of which caused me to
| understand what the general case is, and why e.g. a scalar is a
| rank 0 tensor, a vector is rank 1, a matrix is rank 2 my 3d
| spreadsheet idea is rank 3, etc).
| ninthcat wrote:
| It sounds like you are describing a multidimensional array,
| which can be used to represent a tensor, but is not
| conceptually the same thing. A tensor is an element of a tensor
| product.
| harimau777 wrote:
| Socialism
|
| When I got out of my middle class bubble, made friends with
| people working multiple jobs and struggling to make ends meet,
| and experienced a period of financial instability; I began to
| realize that something wasn't working in our current system.
|
| Then I started struggling with burnout and other issues and found
| that corporations were happy to just replace me. I also found
| that management wanted programmers to be replaceable cogs instead
| of professionals. At that point I started to suspect that the
| idea of a dignified professional lifestyle may not be true.
|
| I observed that technology and products were getting worse over
| time. For example, Google search has become mostly useless and
| it's hard to find products that are made to be repaired. I
| concluded that the invisible hand and/or the price theory of
| value were not true.
|
| Then I saw Republicans gain power and run up the national debt. I
| also observed that when wages actually started increasing the
| economy fell apart and the Fed started taking steps to prevent
| wage increases. I concluded that "free market" rhetoric was a
| lie.
|
| At that point I looked for alternatives and found socialism. In
| particular the "social democracy" strains of socialism as opposed
| to those advocating central planning or anarchist organization.
| rramadass wrote:
| >In particular the "social democracy" strains of socialism as
| opposed to those advocating central planning or anarchist
| organization.
|
| Yes; Most people get hung up on terminology and/or specific
| interpretations but i am convinced this is the natural order of
| things for the Human species. The balance without going to
| extremes is what is important.
| zozbot234 wrote:
| > Most people get hung up on terminology and/or specific
| interpretations
|
| Because terminology matters, and some terms are quite
| misleading. What some people tend to miss about the
| "Socialism with Scandinavian Characteristics" that folks
| claim to like these days is that Scandinavian countries are
| actually near the very top rankings by economic freedom and
| lack of excess regulatory burden. I.e. they're actually some
| of the _most_ free market and capitalist, while applying
| effective redistribution after the fact (leading to
| moderately high tax rates). So I don 't get why people decry
| capitalism and free enterprise while praising Scandinavia as
| "successful" socialism? It makes no sense.
| api wrote:
| I've thought for years that the ideal would be a very free
| market with very little regulation combined with a basic
| income and a strong social safety net.
|
| Let people go wild and try stuff and do whatever but raise
| the floor up to the point where people can recover from
| failure and where the less fortunate are not suffering.
|
| This kind of "social capitalism" could be freer and less
| regulated than what we have now.
| zozbot234 wrote:
| Sure, but the whole issue is how to get from here to
| there given the current regulatory environment. Adding
| even more red tape and wasteful government spending as in
| the orthodox "socialist"/"anti-capitalist" approach is
| unlikely to be helpful.
| xigoi wrote:
| Interesting. Here in Czechia, "socialism" and "social
| democracy" are two very different things -- one is the
| oppressive regime we had decades ago, the other is the current
| system that works reasonably well.
| zozbot234 wrote:
| Czechia is still undergoing catch-up growth, much like
| Germany during the _Wirtschaftswunder_ (that made their
| "social market economy" widely popular) and emerging
| countries today. When people say "social democracy" doesn't
| work all that well compared to leaner approaches, they mean
| countries where that growth process has concluded. With an
| overregulated economy and a high burden of all sorts of
| excess red tape, they tend to get stuck in a middle-income
| trap that leads to widespread unhappiness.
| timnetworks wrote:
| This is not an attack on you, you are free to your opinion and
| to voice any or all of it to whom you choose, largely because
| you don't live on a socialist society.
|
| My opinion, however, is that my parents did the right thing to
| drag me out of such a system and into a capitalistic one. I am
| watching my peers suffer.
| api wrote:
| A big one for me not necessarily for "socialism" but for
| questioning the bog standard capitalist narrative was seeing
| how the quality of content often goes _down_ when creator
| monetization is added on a platform.
|
| That's not supposed to happen. Adding a way for people to make
| income is supposed to incentivize better content and allow
| people to invest in that content. Instead what you get is a
| flood of addictive and sensational / tabloid trash.
|
| ... or another way of looking at it is that you do get "better"
| content but better is not defined in a way that truly benefits
| anyone.
|
| YouTube is the most dramatic example. The quality of the whole
| platform tanked hard when monetization was added.
|
| After seeing this a few times I have started noticing it
| everywhere. The profit motive just doesn't incentivize quality
| the way we are taught that it should. It can when the
| incentives align but they often do not.
|
| Another common example is actual reductions in quality to drive
| more spending like engineered obsolescence or "nerfing"
| software to drive lock in. The incentive is to produce an
| inferior product since that is most profitable.
|
| This doesn't mean I think the answer is a government
| bureaucracy running everything like a single monopoly. That
| leads to a whole other set of perverse incentives and an
| inability to go elsewhere.
| zozbot234 wrote:
| > ... Adding a way for people to make income is supposed to
| incentivize better content and allow people to invest in that
| content. ...
|
| What it does is incentivise _more_ content. More is not
| always better for everyone, and is even less likely to be
| better for those who were early adopters to the platform -
| but what it is usually is more _popular_. It 's just
| democracy in action: the largest numbers decide, and
| sometimes privileged minorities lose out.
| api wrote:
| It's not quantity. It's a change in the nature of the
| content. People start chasing the algorithm and trying to
| amp up the addictiveness of content. You end up with a
| cross between a casino slot machine and a supermarket
| tabloid.
| pintxo wrote:
| Observing the debate in the US from the outside, I believe the
| term "socialism" has to die. It's carrying so much baggage it's
| a major reasons the US cannot have a sensible debate over what
| alternatives there are to full-blown free-market capitalism.
|
| While also somewhat contested in Germany, and not free of
| (some) valid criticism, I would advocate to try and use the
| term "Social market economy" [1].
|
| [1] https://en.wikipedia.org/wiki/Social_market_economy
| mike_hock wrote:
| > full-blown free-market capitalism
|
| Well, full-blown free-market capitalism would be _one_
| alternative to the current US system, albeit probably not the
| best.
| andrewflnr wrote:
| call-with-current-continuation. First ran into it as a teen and
| the concept pretty much completely bounced off my brain. I think
| it took a couple more tries before I started getting it, and
| arguably I'm still working on it.
| catears wrote:
| I have one example and an anti-example. Both are related to
| algorithms and computer science.
|
| A) Packing a binary tree into an array. Anyone that has attended
| an algorithms course has likely created a binary tree with nodes,
| leaf nodes, left and right child etc. Seen the pine-tree like
| sketch with a larger example where each node except the leaf
| nodes have a left and right child. So how do you pack this tree
| into an array and traverse it efficiently?
|
| Well you turn it 90 degrees side-ways, slightly shift all nodes
| on the same level so that none align and put them into an array
| by going from leftmost to rightmost. (or other way depending on
| if you shifted 90 degrees or -90 degrees). Congrats, you've
| packed nodes into an array. How do you traverse it? Our root node
| is at index 1 and if you packed the array correctly then `idx =
| (idx * 2) + 1` will move down one side and `idx = (idx * 2) + 0`
| moves down the other. I don't have a good visual explanation of
| this but you can think of the integer/index as a bit-sequence
| describing when in the tree a left vs. right path was taken (with
| the exception of the root node).
|
| B) Anti-example: Ford Fulkerson algorithm for finding shortest
| paths between all nodes in a graph. The algorithm is basically
| just three for-loops stacked on top of each other, but I still
| can't grasp why it works. Something with dynamic programming and
| incrementally building on prior established intermediate paths.
| The algorithm is truly the product of a beautiful mind.
| arjvik wrote:
| A) I've seen this before but I've never thought of the "index
| as a bit-sequence describing when in the tree a left vs. right
| path was taken" before! This is a very nice intuitive
| explanation that'll really help in describing this to others.
|
| B) Did you mean Floyd-Warshall's?
| Tade0 wrote:
| Singing.
|
| I was part of a choir in high school and early college, but never
| managed to get good at this, even though I knew well how skilled
| singing should sound.
|
| More than a decade later, when I was really exhausted after
| tending to my infant child I let out a sigh of the same type that
| we did as exercise back in the choir("Aaaaaaaah"). To my surprise
| it was almost effortless despite making quite the sound due to it
| being more or less at the resonance frequency of the bones in my
| skull.
|
| And then it dawned on me. It's essentially turning yourself into
| an elaborate fart pillow.
|
| Of course there's much more to that in things like posture and
| the mentioned resonance, but I had that covered from years of
| training. The only piece missing was using the diaphragm
| correctly.
|
| Now I sing daily and while my range is pretty average, I don't
| strain myself any more and can do it for hours. Also the tone is
| just so much better now.
| rolenthedeep wrote:
| It took me an embarrassing amount of time to fully grok what
| object oriented programming really means. It's one thing to have
| someone tell you what an object is, but it's another thing
| entirely to build a fully object oriented system.
|
| I remember what made it click: I was designing an animation
| system, which had a bunch of different interdependent moving
| parts. Once I started treating each part like an object and
| letting it manage its own state it all just clicked. I started
| with this massively complex functional-like system that managed
| four or five different motions, but once it was broken into
| objects most of the code just fell off and it became a nice clean
| system.
|
| I was super proud of it at the time, but it's pretty bad by my
| current standards.
| rileyphone wrote:
| I had a similar shift in perspective recently, that went from
| viewing objects from the outside as things to be manipulated,
| to viewing them from within as independent entities with
| boundaries. What made it click for me was watching Alan Kay
| talks and reading "Object Thinking" by David West. Now, I think
| the idea is due for some sort of renaissance. Though the
| culture of programming has turned against it in favor of FP,
| OOP continues to underlie the most important languages,
| organizations, and products in a way that speaks to its
| ultimate potential: to build evolvable, growable, maintainable
| software systems in service of human flourishing.
| zabzonk wrote:
| I've always found OO programming completely natural. n fact,
| it's the only kind of programming i've ever really done -
| create a structure with data members, and then create functions
| to work on that structure. you can (and should) do this in low-
| level languages such as C and assembler.
|
| Of course, if you want to go the whole polymorphic route, i'd
| suggest using something like c++, but the key ideas are really
| structures, and functions that operate on those structures.
| sureglymop wrote:
| I've always had a hard time because I was thinking.. why
| would I carry the performance hit of instantiating objects
| for a bunch of stuff?
| zabzonk wrote:
| you have to instantiate variables anyway. grouping those
| variables in objects simply makes your code more
| understandable - there is really no extra cost.
| rolenthedeep wrote:
| Why accept the performance hit of copying structs when you
| could use a reference type?
|
| It's a tradeoff. OOP makes sense for certain types of
| problems, and functional programming solves other problems.
| It's very much a case of selecting the right tool for the
| job.
|
| I recently transitioned from C# game programming to C++
| embedded system firmware. Objects don't make much sense for
| what I'm doing now, and I'm coming to see the elegance of
| functional programming.
|
| There is no one answer, just a box of tools. What makes a
| good programmer is understanding each of your tools well
| enough to decide which one will solve your problem in the
| way you want.
| opportune wrote:
| As someone who started programming in BASIC, OO is a really
| good way to think about stuff (it introduces the abstraction
| of "conjoined data" that is typed and has functions) but it
| was not natural. It just feels natural now that I've spent so
| long in school and at work dealing with OO languages. I
| imagine if you had started with BASIC you'd feel the same
| opportune wrote:
| My first job was doing mostly Lego-pieces greenfield
| development. I learned a lot, but also didn't learn as much as
| in my second job where I started having to work with a much
| more complicated, slightly "legacy" system with a big codebase.
|
| At small code sizes, OO does not really have any apparent
| advantages to doing everything imperatively or in a hacky way.
| In fact I'd argue it tends to overly complicate and obfuscate
| things. But there is a point at which you really start wanting
| OO instead because you can no longer reason about the binary as
| a whole, and need to start thinking in terms of interfaces with
| separation of concerns. Even if you did understand the whole
| state, there are too many people working on it to keep up with
| changes to the whole state in a way that lets you reason about
| the thing as a whole.
|
| At my first job (and in college) code never reached such levels
| of complexity so OO always seemed like some dumb fad to make
| things more complicated than necessary. I still that is often
| the case, but now I absolutely see the benefits when they
| present themselves.
| AndyNemmity wrote:
| This one is the same for me. I'm not even sure I still totally
| get it.
|
| It feels like something used an awful lot in ways that don't
| really add any value. But again, it must just be my lack of
| understanding. Maybe one of these days it'll click in.
| rolenthedeep wrote:
| In my animation system, I had a laser beam projecting from a
| fixed point to a movable point in space. There are also
| sprites which travel up and down the beam.
|
| Moving the beam endpoint required an animation to bring the
| width to 0, change the endpoint, then ramp the beam width
| back up. The sprites each have their own animation in
| different conditions, and moving them along the beam is
| another animation.
|
| The real key for me was the sprites. I built a class which
| takes in the start and end points of the beam and an update
| method. Once you start the sprite up, you just have to poke
| it every frame with the time delta and it manages all of its
| own animations.
|
| Likewise, the laser itself was an object that managed its own
| animations and the sprites related to it.
|
| This resulted in a bunch of objects with just a little code
| in them. But because the concerns are separated, it results
| in less code overall than it would take to manage everything
| all at once.
|
| Is this the best, or even a good way to do this? Probably
| not, but it was a very beautiful solution in the moment
| moloch-hai wrote:
| You don't really understand OOP until you recognize it as one
| style among many that you may use in different parts of each
| program. Some parts are naturally OO-y, others DD-y, others
| declarative, often an unholy mix in each place. The problem
| dictates elements of the solution. Shoehorning a solution into
| a particular style makes a bad solution.
|
| Never forget who is in charge. Deferring to a style dodges
| responsibility for your choices.
| ShredKazoo wrote:
| DD?
| bitwize wrote:
| Domain-driven or data-driven (not sure which).
| dopidopHN wrote:
| My guess would be domain driven design.
|
| I remember that being all the rage 10ish years ago? I think
| it works, but I don't see it much anymore
| czx4f4bd wrote:
| I didn't fully grok OOP until I saw how composition and dynamic
| dispatch can be used in real code to create abstractions and
| flexibly swap out different implementations for your
| interfaces.
|
| You could build a chatbot that supports Discord, Slack, and IRC
| dynamically at runtime, or a web app that can use multiple
| different database engines, or a social network with multiple
| types of posts that can all be rendered in a main feed, or a
| bunch of other things. In all of these cases you can also take
| advantage of this kind of dynamic dispatch to inject mock
| objects for testing, as well as theoretically have an easier
| time swapping out a layer if you want to change a dependency.
|
| What really frustrates me is that almost none of the OOP
| instruction I've encountered ever showed these kinds of real,
| practical examples. They always over-emphasize harmful
| inheritance-based approaches and never really explain
| composition. In college we learned about OOP by building a
| little text-based RPG thing with different types of monsters
| implemented as subclasses of an abstract base class, which left
| me feeling like there wasn't much practical use for it outside
| of game development.
|
| It wasn't until my first internship that I saw a real-world use
| of OOP, in the form of a giant Spring Boot monolith with tons
| of dependency injection. Eventually, after staring at that for
| a few months, OOP finally clicked for me, but I still find it
| annoying that nobody ever tried explaining this using
| practical, small-scale examples.
| analog31 wrote:
| I read the earliest articles on OO and SmallTalk in Byte
| Magazine, which IIRC would have been the early 80s. OOP was
| totally and utterly bewildering to me, a BASIC and Pascal
| programmer.
|
| It "clicked" much later, in two stages, using languages that
| were "kind of like" OOP, even if not rigorously so: LabVIEW,
| HyperCard, Visual Basic. I think VB had a decent strategy for
| introducing OO to the rest of us. Out of the box, it was
| "object based," meaning that you could use classes that had
| been created by someone else. For a bit more money you could
| buy the version that let you do full OO, but I never did that.
| But by being a _user_ of objects, it gave you an idea of what
| you 'd want if you could create them for yourself.
|
| Nowadays of course people range from being bullish to bearish
| on OO, and I've had the experience of doing it badly and making
| a mess of things, when a procedural or functional model would
| probably be better.
|
| Kind of a lesser issue is that I finally grasped how to work
| with a modern OS after laying my hands on the first couple
| volumes of the Win32 programmer's manuals, which I think were
| vastly less forbidding than _Inside Macintosh_.
| layer8 wrote:
| > the first couple volumes of the Win32 programmer's manuals
|
| What books exactly are you referring to here?
| gurchik wrote:
| When I was younger I had a lot of trouble with OOP. It probably
| didn't help that my two strongest languages at the time (PHP
| and Python) allow you to use them fully iteratively if you
| want. For some reason I never found an explanation that focused
| on state. A lot of the examples I saw I remember thinking it
| made a lot more sense to just rewrite the functions so they
| aren't part of a class.
|
| I still frequently see code examples online that are written
| using classes that don't need to be. I imagine this is the
| reverse problem: people from languages like Java thinking
| everything has to be in a class.
| kevinmchugh wrote:
| Yes, looking back I was shocked to realize how little my oop
| education and work had talked about state
| narag wrote:
| That Pareto is everywhere and, when applied to knowledge, a
| comprehensive study plan, like courses or a book, for most
| subjects, tend to obscure what's the meat.
|
| Waking call:
|
| https://sive.rs/kimo
|
| Corollary: a place where there's a fat-ass book of "best
| practices" has probably lost its focus.
| bsuvc wrote:
| Unit testing and using dependency injection to write test-able
| code.
|
| I'm not sure if it was years, but it wasn't immediate. I just
| didn't understand why dependency injection was good at first, and
| not just someone's weird personal code style choice.
|
| I thought it was just people being "Enterprisey" which I'd
| encountered many times over the years.
|
| Once I committed to unit testing, I realized how necessary it is.
|
| Unfortunately I still encounter customers who haven't bought into
| it and as a result have untestable code. It's so hard to go back
| and retrofit testing.
| everybodyknows wrote:
| > dependency injection
|
| The term is unfamiliar to me -- is it related to "fault
| injection"?
| gavinray wrote:
| Going to steal a description I wrote for a blogpost several
| years ago, when I had recently understood DI for the first
| time so it was very fresh in my mind:
|
| https://hasura.io/blog/build-fullstack-apps-nestjs-hasura-
| gr...
|
| Dependency Injection solves the problem of when you want to
| create something, but THAT something also needs OTHER
| somethings, and so on.
|
| In this example, think about a car.
|
| A car might have many separate parts it needs:
| class Car { constructor(wheels: Wheels) {} }
| class Wheels { constructor(tires: Tires) {} }
| class Tires { constructor(rims: Rims, treads: Treads)
| } class Rims { constructor() {} }
| class Treads { constructor() {} }
|
| We can manually construct a car, like: const
| car = new Car(new Wheels(new Tires(new Rims(), new
| Treads())))
|
| But this is tedious and fragile, and it makes it hard to be
| modular.
|
| With dependency injection, it allows you to register a sort
| of "automatic" system for constructing an instance of "new
| Foo()", that continues down the chain and fetches each piece.
| class NeedsACar { constructor(@Inject private car:
| Car) {} }
|
| And then "class Car" would have an "@Inject" in it's
| "constructor", and so on down the chain.
|
| When you write tests, you can swap out which instance of the
| "@Injected" class is provided (the "Dependency") much easier.
| sanderjd wrote:
| The first example is also dependency injection. The rest of
| what you described is why a dependency injection
| _framework_ often becomes useful in a system with a large
| dependency tree.
|
| The alternative to dependency injection is for functions to
| instantiate dependencies internally rather than having them
| be passed in from the calling context.
| lamontcg wrote:
| I'd probably reach for a Builder pattern first for that
| rather than go full DI container.
| TillE wrote:
| I know the car is a classic, cliche OOP example, but for
| any semi-experienced programmer, I feel like it's a really
| bad choice of analogy which only serves to obscure how you
| would use a technique like DI in actual real-world code,
| rather than an artificial toy example.
| jacobsimon wrote:
| I think you might have it backwards. The first example _is_
| dependency injection, too, since you are passing the
| required instances into the constructor. The non-DI
| approach would be for the Car class to import and
| instantiate the Wheels class inside its constructor
| function.
| dymk wrote:
| You'd do fault injection by injecting dependencies that
| respond with / throw faults.
| rozap wrote:
| People would have way fewer opinions on it if it was just
| called "passing stuff in"
| itronitron wrote:
| Dependency injection is one of those technical terms that are
| made up to describe something that has been done for decades
| but with a new name because the creators of the new term
| don't have much experience and/or they want to gain notoriety
| for creating a new programming technique.
|
| If you've ever written a constructor for a class that has
| arguments (within the constructor signature) that are used by
| the instance of the class when instantiated then you have
| done dependency injection, or put more simply 'passing stuff
| in' which was eloquently stated in another comment on this
| thread.
| kagakuninja wrote:
| I believe the term Dependency Injection was coined by
| Martin Fowler, as the meaning of the pattern name Inversion
| of Control is less obvious. I'm going to assume that Martin
| Fowler has quite a bit of experience, although you might
| accuse him of wanting to gain notoriety...
|
| In any case, DI is not at all a new trendy term. Inversion
| of Control dates back to the gang of 4 patterns book from
| the '90s. Yes, constructor parameters are one way to
| implement DI, but not the only one. I'm ambivalent on the
| whole pattern movement, but they are a great educational
| tool for novice programmers, and it is good to have some
| standard terminology for core patterns.
|
| To put it another way, constructor based DI is not simply
| the use of constructor parameters, it is understanding the
| OO design principle that side-effecting code should be
| isolated into objects, rather than just dumping a bunch of
| DB queries into your functions, like we did back in the
| stone age.
| la_fayette wrote:
| No it is a design pattern to structure code. It is also known
| as the hollywood principle (don't call us, we call you).
| Meaning that dependencies of a class are provided from the
| outside, the class itself doesn't know how to create
| instances of dependencies, just relys on the dependency
| container (also named inversion of control)...
| okino wrote:
| Good series about the approach from a functional perspective
| https://fsharpforfunandprofit.com/posts/dependencies/
| ngc248 wrote:
| It is a pattern where you inject the dependencies of a class
| into it rather than create the instances of the dependencies
| within the class. for more info -->
| https://en.wikipedia.org/wiki/Dependency_injection
|
| it makes the code cleaner and testable.
| everybodyknows wrote:
| What I find troubling about that page is that it does not
| qualify up front whether the dependencies are:
|
| A. Also depended upon by other, coequal unrelated classes,
| possibly maintained by others, OR
|
| B. Depended upon only by a single class (of higher
| functionality)
|
| Situation A is sometimes called a _portability_ interface;
| B might be called an _internal structuring_ interface.
|
| The difference has crucial implications for social power
| relationships between the human developers and users
| involved.
| azeemba wrote:
| Let's say Class A depends on Class B. A lot of people have
| the instincts to have A construct B so that the callers of A
| don't have to worry about it.
|
| But this makes testing A in isolation difficult. When testing
| A, you want to mock out B with an instance the test can
| manipulate.
|
| So we want A to not create B, instead we want B to be
| "injected" into A. The general strategy of having B passed
| into A is called dependcy injection.
| k__ wrote:
| The idea of DI is that you creat resources indirectly, and
| don't call the named constructor in your code. You then use
| interface types to interact with the resource.
|
| This way, your code isn't bound to a specific implementation.
|
| Some DI frameworks even go so far and define all resources in
| a config file. This way you can switch out the implementation
| without a recompilation.
| [deleted]
| Simon_O_Rourke wrote:
| I think the poster is referring to Guice or something similar
| - that there's a framework which selects which instantiated
| runtime object gets injected as a dependent into another,
| thereby automatically "figuring out" what object needs to get
| instantiated first, and then next etc.
| groundcoffee wrote:
| +1 to this. It doesn't help that some dependency injection
| frameworks' (ahem, looking at you Dagger2) error messages can
| be convoluted and hard to understand.
| rr808 wrote:
| Agreed, this has taken me years. It also is tough because lots
| of people over use it IMHO. When the logic keeps bouncing
| around dozens of classes its too hard to follow, even if its
| easy to test.
| lamontcg wrote:
| I keep looking for a reason to write software using a proper DI
| container framework. In talking to Java devs most of them just
| mention injecting mocks for your database. You don't really
| need a full DI container for that you could use a service
| locator instead or some even lighter DI pattern. If you have
| that particular hammer though and know how to use it, then it
| becomes easy to achieve and use config to inject your backend.
|
| But that's a long way from glorious full DI containers where
| you never call 'new' in your code anywhere and all object
| creation can be dictated by config. I suspect that must be only
| the kind of thing that people who maintain 1,000,000 line
| codebases that are at the center of massive bureaucracies.
| mrfox321 wrote:
| At my bigco, there's no service-level DI (c++)
|
| Just vanilla C++ classes, and virtual interfaces if we need
| to mock things for unit tests.
|
| No automatic wiring of the hierarchy.
| number6 wrote:
| Can you explain the concept? I feel I didn't grok it fully
| ericlewis wrote:
| Not sure about poster above, but I found a large amount of
| value in writing tests when developing API backends. I knew
| the shapes and potential data. Was easier to write tests to
| confirm endpoints looked right than manually hit the api
| endpoints.
| latchkey wrote:
| Always amuses me when I see tests spin up a http server,
| just to call a function.
| pintxo wrote:
| What specifically amuses you?
|
| Todays http servers may have any number of request
| altering/enhancing "middleware" calls between the
| incoming request and the actual business logic/function.
|
| How do you ensure that your api works as designed if you
| only test (pure) business functions? Or do you re-create
| the middleware chain of functions manually for you test?
| ericlewis wrote:
| technically this would be considered an integration test
| I think.
| latchkey wrote:
| /api/foo -> fooApi()
|
| You don't need to test the call to /api/foo, you only
| need to test the call to fooApi(). It doesn't/shouldn't
| require a http server to do that. Just call the function
| directly.
|
| If you want to test that /api/foo exists, that is
| essentially a different test and only requires a mock
| version of fooApi(), because you've already tested
| fooApi() separately above.
|
| The benefit of this approach is that your tests run _a
| lot_ faster (and easier) not having to spin up an entire
| http server, just to test the function.
|
| As for the middleware... that is also tested separately
| from the business logic. You don't want to tie your
| business logic to the middleware, now do you? That
| creates a whole dependency chain that is even harder to
| test.
| ericlewis wrote:
| Sorry, I probably wasn't clear. I wasn't spinning up the
| server itself, just testing the endpoints via their
| functions. Though this likely falls more under
| integration vs unit tests.
|
| As for unit tests... I mostly add them to projects with
| something egregious happens or a very hard bug to spot
| can occur - just to prevent anyone else from foot gunning
| themselves (here be dragons or whatever).
| latchkey wrote:
| You were clear. I was agreeing with you.
| grogenaut wrote:
| It used to be hard. I just spent a day in c# and gql
| figuring out how to do API level tests with a new
| framework. But when you get it working it's ever so much
| faster.
|
| https://github.com/gaffo/CSharpHotChocolateZeroQLIntegrat
| ion...
|
| Still playing around with the right level for this but
| this is currently nice as it gives me compiled type
| checking and refactoring. This is an example/extraction
| from another project which uses react as the client.
| Wasn't big on cross language api level tests yet for
| speed of development, as that's a tradeoff. Redundancy vs
| even more framework.
| niklasd wrote:
| I found this explanation very helpful:
| https://hakibenita.com/python-dependency-injection (if you
| program in Python)
| closeparen wrote:
| Seven years into my career I'm increasingly convinced that the
| emperor has no clothes with respect to unit tests that are just
| transcripts of the code under test with "mock.EXPECT()"
| prepended to everything - 95% by volume of the unit test code
| I've ever read, written, or maintained.
| grogenaut wrote:
| I call those lockdown tests and they're a smell. You don't
| want to dictate the implementation, just the inputs and
| outputs. The former leads to very brittle code, the latter
| describes and validates the contract. It's also important
| where you put the logic of the test in the code base when you
| have multiple layers. This latter part is harder and system
| dependent.
|
| In many cases mocks are now over used where previously they
| were important in say 2008. Especially now with languages
| that support functions as objects, better generics, and other
| features which weren't common a while back. Likewise
| frameworks are and languages are generally way more testable
| now which means you're doing less backflips like static
| injecting wrappers for DateTime.now into libraries to make
| tests work. This further allows more contract and less
| implementation specific testing.
|
| As with most things there is a lot of nuance/art to doing it
| well and smoothly
| bsuvc wrote:
| Yeah, the mere presence of unit tests is not enough. It has
| to actually assert something useful.
|
| When I code review, I try to make sure I call out "fake
| tests".
| lscharen wrote:
| That's a great point. Seeing lots of mocks and assertions
| that certain functions are called is often much ado about
| nothing since no actual code functionality is exercised. I
| do sometimes see the return value functionality of mocks
| used as a stub, just because the dev hasn't internalized
| the distinction and can "make it work" with a mocking
| library.
|
| One of the only legit use cases for mocks that I have
| personally come across is validating things like a sequence
| of API calls to an external service, or queries to a
| database where there is a check that certain efficiencies
| are guaranteed, e.g. verify that an N+1 select problem
| doesn't creep in, or knowing that a app-level caching layer
| will prevent redundant API calls.
| closeparen wrote:
| The useful assertion to be made about gateway/repository
| layer code is that it gets the expected behavior out of the
| dependency. This is not an assertion you can make when
| you've mocked out the dependency. You must make it in an
| integration test, not a unit test. Unit tests in these
| layers just make assertions about "it calls this method on
| the client" or "it sends this string," which tells you
| nothing about whether doing that is actually correct.
|
| It's relatively uncommon for handler/controller code to
| have logic worth testing, most of the time it's just
| maintaining the separation of layers and concerns by
| wrapping gateway/repository calls. All there is to assert
| about it is that "it calls this function in the next
| layer."
|
| Every once in a while there's nontrivial functionality to
| test in the middle, and unit tests can often be a good fit
| for that, but in my experience it's more the exception than
| the rule.
| sanderjd wrote:
| Yep, I think mocks are mostly a smell. The "functional core"
| of a module should be entirely or almost entirely unit
| testable with (possibly fake) dependencies passed in. The
| glue code ("imperative shell") should be tested at a higher
| level - "integration" or "end to end" or whatever you want to
| call it - which looks at the externally observable effects of
| running the code (database changes or API responses or
| whatever) rather than the details of its execution.
| Scubabear68 wrote:
| Amen. I have been frustrated at many jobs where developers
| were so proud of endlessly writing mocks and spending more
| time on their tests than on core functionality.
|
| Over time I have favored very basic unit tests and leaning
| in more on automated integration and regression tests. I
| know the theory of unit tests catching things earlier, I
| just don't think it matters in practice.
| sanderjd wrote:
| I think in practice unit tests are both the most and
| least useful tests. Unit tests of code that just
| generates output as a function of input are the most
| useful, and unit tests of code that just glues together a
| bunch of side effects are the least useful. I like to
| find ways to structure things so that it is mostly
| comprised of the first kind of code, and has so little
| logic in the second kind of code that it's easy to
| justify not unit testing it.
| alpaca128 wrote:
| I once saw type checking presented as kind of an
| alternative to unit tests which doesn't rely on the
| assumption that developers write good tests, and I really
| like that viewpoint. A powerful type system can prevent
| many bugs, doesn't need additional test code and doesn't
| make any assumptions.
|
| Of course it's not necessarily a full replacement, but
| it's definitely better and more time efficient than bad
| tests.
| sanderjd wrote:
| Yes, static analysis of types can eliminate a big class
| of unit tests (basically just checking pre- and post-
| conditions on types), which is a big part of why it's
| great. But _most_ unit tests should be for logic. But
| that 's why they aren't very useful for "glue" methods
| which just thread things through different dependencies -
| they shouldn't have much interesting logic.
| [deleted]
| closeparen wrote:
| This is the way, but it's tough to sell "we're not going to
| unit test this part" in a professional setting where there
| are incentives to look more responsible than thou,
| directors are looking at unit test coverage reports, etc.
| sanderjd wrote:
| Yeah I have no qualms about writing mostly-BS unit tests
| when the existing structure of a project makes it
| infeasible to write good ones. When in Rome! But when I'm
| starting from scratch or have a chance to do refactoring,
| I move toward the "functional core" approach as much as
| possible.
| delecti wrote:
| How are mocks a smell if "unit testable with (possibly
| fake) dependencies" is okay? That's what mocks are.
|
| Or do you mean specifically "expecting" interactions with
| those mocks? Because I agree that's usually not that
| valuable.
| sanderjd wrote:
| Basically what Cyph0n said, fakes and mocks aren't the
| same thing.
|
| But it isn't quite as smelly when I see a mock (or "stub"
| more typically) used as an expedient way to create a fake
| to pass in as a dependency.
|
| Like you said, it is asserting on the interactions with a
| mock that is what primarily smells bad to me. I very
| rarely (honestly I think maybe never) see this done in a
| way that isn't just rewriting the implementation of the
| method as expectations in the test.
| Cyph0n wrote:
| Fakes are not mocks. A fake is an actual implementation
| of the dependency that runs in-process/in-memory. This
| means that, unlike with mocks, your test code does not
| dictate the behavior/outputs of the dependency.
|
| Ideally, service/library owners would write and maintain
| the fake to ensure that it stays in sync as changes are
| made to the actual service.
| Izkata wrote:
| I think my favorite of these was a function that called 4
| other functions and didn't do anything else, its unit test
| mocked out all 4 other functions and asserted that each was
| called.
| closeparen wrote:
| Every damn day. It's the thing that puts me most at risk of
| falling out of love with software engineering.
| the_only_law wrote:
| I had a take home test a year or two ago and I got grilled
| during the interview for not writing crap like that.
| monero-xmr wrote:
| Another solution is to eliminate classes and only use structs
| or similar plain objects. Makes mocking and testing functions
| much easier. At this point I see no reason for OOP whatsoever
| and consider it a big mistake.
| [deleted]
| alpaca128 wrote:
| OOP tends to encourage thinking in more abstract ways than is
| often necessary imho. I feel like learning a language with
| only structs had a positive effect on my coding ability (as
| someone who more or less started with Java).
|
| The few times I had to use Java afterwards I felt the same -
| all OOP features were unnecessary or at least didn't feel
| like the most straightforward approach. Nowadays I never use
| classes in Python, JS etc., it's just not needed - and in the
| case of Python it makes JSON insanely cumbersome.
| sanderjd wrote:
| This seems totally orthogonal to me.
|
| Using a totally non-OOP functional style, you can either
| instantiate state within a function or pass it in from the
| calling context, which is the same trade-off that dependency
| injection targets.
| monero-xmr wrote:
| If you work on a legacy code base with tens of many
| millions of lines of code, the non-OOP will be a better
| code base. My opinion.
| sanderjd wrote:
| I wasn't disagreeing (or agreeing) with that opinion.
| It's just orthogonal to whether or not dependency
| injection is a useful approach.
| optymizer wrote:
| Getting rid of data abstraction and encapsulation is throwing
| the baby with the bath water.
|
| The abstract concept of OOP (messages between complex
| objects, as defined by Alan Kay) is an attempt at mimicking
| biological systems. Most modern languages implement data
| abstraction, but call it OOP, where they encapsulate some
| functionality with the data it operates on. Really helped
| with varying data formats in the AirForce in the 60s,
| apparently. There isn't anything wrong with this abstract
| concept either - it's a way of structuring a solution, with
| trade-offs.
|
| Support for unit testing and mocking has little to do with
| OOP, and everything to do with the underling platform. Both
| C++ and Java, for example, do not have a special runtime mode
| where arbitrary replacement of code or data could occur. This
| is necessary for mocking functionality that is considered
| implementation detail and hidden by design. The hidden part
| is great for production code, not great for testing.
|
| For example, if an object in java has a field like 'private
| final HttpClient client = new CurlBasedHttpClient();' this
| code is essentially untestable because there is no way in
| Java to tell the JVM "during testing, when this class
| instantiates an HttpClient, use my MockHttpClient".
|
| Kotlin fixed some of that with MockK, which can mock the
| constructor of a Kotlin object, and you can return your mock
| implementation when the constructor is invoked.
|
| Clearly, it's a platform issue. There could be a world where
| you could replace any object in the stdlib or any method or
| field with a mock version. JavaScript is much more flexible
| in that regard, which is why unit testing js code is much
| easier.
|
| The root of it all stems from the fact that unit tests need
| to change some implementation details of the world around the
| object, but production code should not be able to, in order
| to get all the benefits of encapsulation.
|
| If you get rid of modern OOP, you are swinging the pendulum
| in the opposite direction, where your tests are easy to write
| on any platform, because everything is open and easily
| accessible, but your code will suffer from issues that creep
| up when structures are open and easily accessible, such as
| increased coupling and reduced cohesion.
| taffer wrote:
| OOP does not have a monopoly on abstraction and
| encapsulation. What OOP does, namely object-level
| encapsulation, is just a very extreme way of structuring
| code around mutable state. IMO the better alternative is to
| avoid mutable state as much as possible and keep data and
| code separate. Code structured as pure functions is easy to
| test and encapsulation can be done at the module level.
| kagakuninja wrote:
| OOP does not require mutable state. OOP has its origins
| in imperative languages, and so in the past OOP often
| involved poor management of mutable state.
|
| I am a Scala programmer, and our code mixes OO and FP.
| Almost all of our classes are completely immutable.
|
| In the end, you will always need to encapsulate data and
| functions in some manner. The FP approach involves module
| systems, but as I understand it, objects in Scala
| actually provide a better module system than found in
| pure FP languages.
| optymizer wrote:
| My point is that improving the state of unit testing has
| little to do with OOP, and everything to do with the
| environment that the code runs in.
| monero-xmr wrote:
| I believe that combining state and functionality - the root
| of OOP - is a mistake. Tons of programming patterns and
| concepts exist to solve this fundamental mistake. When you
| stop using classes all of your code becomes so much
| cleaner, easier to reason about, test, debug, and so on.
| You can never create only pure functions in the real world
| but you get closer to this ideal.
|
| I stand by my statement that OOP is totally unnecessary.
| sirsinsalot wrote:
| Yes but if you represent 2 functions over some state a(s)
| and b(s) then you have the same issue with this as if it
| was:
|
| Class s: fun a(self)... fun b(self)...
|
| The problem is mutability not how state is bound to a
| function.
| JanisErdmanis wrote:
| The idea is to make the functions pure and return the
| state 'a(s_1) -> s_2, value'. Makes so much easier to
| test and write concurrent programs.
|
| Though it's not always practical, like when needing to
| push an element to an array for making updated state. It
| is nevertheless possible to shave of pure parts
| considerably making mutability easier to maintain.
| maphew wrote:
| I don't understand but am intrigued. Can you point to
| some resources that elaborate on and demonstrate what
| you're talking about here?
| optymizer wrote:
| You can believe that the world is flat, announce that
| boldly and stand by your statement. It doesn't mean it's
| true in reality, only that it's true in your mind.
|
| Edit: This is more blunt than I intended it to be. For
| what it's worth, I happen to agree with you in principle,
| but I also think you're taking the roof off the car here
| and boldly claiming that the experience is so much better
| in the summer. What about winter? What about when it
| rains? What are the trade-offs? Not mentioning the
| downsides means that you either haven't found them,
| haven't thought about them or are intentionally omitting
| them from the discussion.
| Olreich wrote:
| Recursion is an obfuscated way to run a loop with a stack.
| At first it seems like magic, and makes things so much
| easier. When trying to replicate it the first time actually
| using a loop and stack it's really hard to get right. But
| by the time you've done it two or three times, it's as easy
| as breathing.
|
| Similar, OOP is an obfuscated way to run a function with a
| context. The first time you separate the data in the
| context from an object, it'll be hard to get it right and
| make it easier than to just use Objects and Methods. But
| once you've done it two or three times, it's as easy as
| breathing.
|
| You can optimize loading the context to be better than
| copying a bunch of unaligned data in lots of ways, but
| polymorphism is a common way to get there.
| adlpz wrote:
| I agree with OOP not being needed at all, but I don't agree
| on this being an alternative to dependency injection.
|
| However you structure it, there will always be "glue code"
| that ties the nice inmutable code with the _outside-
| interacting_ bits, and if you want to unit test those,
| dependency injection (with functions or state, not classes or
| instances) is still the way to go.
| mrloba wrote:
| True, but there might not be a big need for unit testing
| the glue code. By its very name it doesn't contain much
| logic to test. Integration tests are more valuable in this
| case.
| Traubenfuchs wrote:
| I'll add to that: the difference between "offline" unit testing
| and spring integrarion testing with test containers and real
| application contexts + all the related concepts like @SpyBean,
| @Mock, @MockBean...
|
| I always hated testing and I still do, but every time I commit
| to doing it right I catch so many errors before QA.
| rubicon33 wrote:
| Eating fiber.
| em-bee wrote:
| object oriented programming.
|
| i must have encountered it during my computer science classes and
| i certainly did some form of oo programming with LPC in MUDs, but
| only when i was programming modules in Pike for the Roxen
| webserver, it really clicked how oo programming worked.
|
| in Roxen each http request causes a request object to be
| instantiated which lives for the lifetime of the request.
| further, each Roxen module gets instantiated as an object for the
| lifetime of the server process. the request object would call
| module objects to process the request. the modules would make
| changes to the request object which would produce the response to
| the http request, whereas storing data in a module object caused
| it to be persistent.
|
| i have been working on this for a while when one morning i woke
| up with a literal eureka moment as i realized how objects and
| encapsulation worked.
|
| this happened a few decades ago and it was the most clear moment
| of this kind that i can still remember.
| thyrox wrote:
| The power of follow ups (especially in sales)
|
| One thing which held me back for a very long time was not
| following up with people who didn't show much interest initially.
|
| I wasted so many good leads thinking it is impolite to follow up
| with people after contacting them once. My whole life changed
| once I understood the power of follow ups and understanding that
| most people are so busy that it takes at least 6 reminders before
| most people will take any substantial action.
|
| The reverse is also true. People say a lot of things and most of
| the times you never cross the bridge or reach it. Nowadays, I
| rarely argue about anything and don't act on stuff until a person
| reminds me once or twice. This small filter can be like a miracle
| for saving your time and energy.
| satvikpendem wrote:
| Agreed. When I was doing sales, I would follow up with people
| seven times before they replied. I used to feel bad until I
| realized that it worked, then I just automated that part and
| didn't think about it further, the leads once they replied were
| sent to my CRM where I could then set them up on a call or some
| other action.
| aj7 wrote:
| You were not trained well.
|
| The principal element in sales is asking for the order.
| Everything, and I mean everything, follows from that. If you
| had been trained this way, following up would be second nature.
| krosaen wrote:
| The Kalman filter. I felt like I understood it watching some
| videos but it always turned out I didn't really understand it
| well enough to put it to use or explain it to others.
|
| Gaining a better understanding ultimately just took a lot of time
| playing with the equations and understanding how measurement and
| process noise/uncertainty get incorporated into the Kalman gain,
| and how that in turn affects the updated state estimate - e.g if
| you have zero noise in the measurement, you end up fully trusting
| your measurement. This tutorial [1] is the one I ended up
| studying. This is a case where memorizing the equations (with the
| help of Anki) helped me reflect on them and keep everything in my
| head long enough to improve my understanding.
|
| http://www.cs.unc.edu/~welch/media/pdf/kalman_intro.pdf
| passion__desire wrote:
| > This is a case where memorizing the equations (with the help
| of Anki) helped me reflect on them and keep everything in my
| head long enough to improve my understanding.
|
| Dr. Mark Colyvan once preparing for his test couldn't
| understand a proof. So he went ahead and tried to memorize it
| anyway but in the process of memorizing he understood the proof
| so he had no need to memorize it now.
|
| https://www.youtube.com/watch?v=KqYh1h2t8WU
| mustafabisic1 wrote:
| For me it was basic statistics. Statistical significance and
| variability.
|
| Had Statistics in college, but only understood it now that I use
| it to understand data.
| _huayra_ wrote:
| Pretty much anything related to _personal growth_ (however you
| define it) takes time to click, but it took a while to understand
| two things at a deep enough level to begin to make change:
|
| * everyone has a set of habits that served them well during
| childhood, but may be maladaptive as an adult (e.g. getting angry
| is almost universal a sign of this maladaptive childhood habit
| rearing up). Book recommendation [0]
|
| * the _fear of hope_ is a key thing to understand when it comes
| to why people (myself included) hold themselves back. Taking the
| first step can feel terrifying because it demonstrates that one
| is responsible for creating one 's own life. Book recommendation
| [1]
|
| The only way out of this is to deliberately design your days so
| that you get the most out of them, even if it is fumbling at the
| start. Add in some times to relax here and there, but if you have
| a plan, it's much easier than staring at a blank Saturday with
| the vague goal of "I MUST learn JS/Rust/Go/Scala or my career
| will be over!!!" and then getting nothing done.
|
| [0] https://www.goodreads.com/book/show/23129659-adult-
| children-...
|
| [1] https://www.harpercollins.com/products/how-we-change-ross-
| el...
| thesnide wrote:
| Working with others.
|
| Really.
|
| I was super annoyed and insanely annoying to work with for years.
|
| Then I understood that difference is hard to cope with, but more
| often than not, good. As it trades some short term efficiency to
| long term one.
|
| Same with your output. If it is dumbed down to a level everyone
| can understand it, you _really_ learned it.
| mattbaker wrote:
| That's cool, what kinds of things helped you learn this? I bet
| those things would be really valuable to a lot of people if you
| felt like sharing.
| thesnide wrote:
| I'd say _parenting_ is the one that really made a difference.
|
| Not because I had a strike of common sense, but because I
| actually cared very much and started to listen to others. I
| didn't want to be horrible to my kids.
|
| So "starting to listening to others". Every troll has a
| kernel of truth. And sometimes what you consider a troll
| isn't one in the first place.
|
| Which is very apropos those days, where everyone is confined
| in their own echo chambers by all those clever social media
| algorithms that always favor short term bliss.
|
| And yes. Trying to explain things to my kids enables me to
| understand those things _way_ deeper.
| tezza wrote:
| 1/2) Trusting Institutions
|
| Institutions such as Police, Universities, NHS, Scouts, MsF,
| Religions, Churches, YCombinator et alia have a hierarchy of
| internal loyalties in strict precedence:
|
| * The Staff Member
|
| * The Staff Member's Family
|
| * The Friends of the Staff Member
|
| * The Colleagues of the Staff Member
|
| * The Group within the Institution the Staff Member belongs to
|
| * Wider Groups in the Institution
|
| * The actual powerbrokers within the Institution
|
| * The acknowledged Leadership of the Institution (may be
| different to actual powerbrokers)
|
| * The actual goals of the Institution
|
| * The acknowledged goals of the Institution (may be different to
| actual goals)
|
| * Helping YOU in accordance with what the acknowledged goals of
| the Institution are...
|
| Only when all the loyalties in that list are satisfied is there
| the slightest chance you may get anything positive from the
| Institution.
|
| Despite the long list of higher precedence loyalties it is still
| frequently possible to have positive outcomes...
|
| But because it is a long list of loyalties far more important
| than helping YOU, there are often breaks.
|
| And because people and families and relationships are involved
| they can change at any moment.
|
| So trusting Institutions to do the best for you or act honourably
| needs to be carefully weighed against the likelihood that will
| happen
|
| 2/2) Mortgages
|
| How mortgage repayments change over time as you pay off some of
| it (YMMV)
| _huayra_ wrote:
| > How mortgage repayments change over time as you pay off some
| of it (YMMV)
|
| This is a big one people buying houses recently due to FOMO
| don't understand: you're really not building equity the first
| few years because almost all of your monthly payment is going
| to interest. The "irrecoverable cost" of owning a home can
| often be higher than renting in some HCOL areas now, although I
| understand that people buy for more emotional reasons (e.g. not
| wanting to yank their family around to a new place each year to
| avoid being at the mercy of a bad landlord on each lease
| renewal).
| LAC-Tech wrote:
| I'm currently doing a dive into classic distributed systems
| papers, mainly from the 70s (actor model, logical clocks, that
| kind of stuff).
|
| I'd "understood" the concepts before, but now because I am:
|
| - brushing up on my math to understand every equation or proof
| they drop in there
|
| - reading them in combination with applied stuff that uses the
| same concepts, ie the "designing data intensive applications
| book"
|
| - reading over them slowly, I want my fundamentals to be strong
| and etched into my head
|
| Things are clicking in a way they never did before.
|
| TL;DR - studying compsci concepts, slowly, from multiple angles
| (completely mathematical to practical engineering) is just a
| different level of understanding from doing one or assuming your
| mind will bridge the gap.
|
| YMMV.
| Nimitz14 wrote:
| Fourier transform
| nathanmcrae wrote:
| For me it was lambda calculus. I remember in high-school going
| through the motions of beta-reduction but having no idea what it
| meant. Much later I think I finally saw an implementation of
| natural numbers and addition using bare lambda calculus and it
| clicked that you really can represent any computation with just
| variables, abstraction, and application.
| gpsx wrote:
| This is something that clicked after a few hours rather than a
| few years, but it is similar in a way. A long time ago when I was
| a graduate student I was in the library one afternoon studying
| some idea in field theory (physics). It covered maybe three pages
| in a small book, but it wasn't making any sense. Finally, hours
| later it suddenly became clear, and it was so simple. I remember
| saying to myself, "Why didn't they just say that?" I looked back
| at the book and they said exactly what I would have said. I guess
| sometimes words are not enough.
| apienx wrote:
| Bayes theorem really clicked when I saw 3Blue1Brown's visual
| representation. https://youtu.be/HZGCoVF3YvM
| dionidium wrote:
| I was at a Denny's around 2AM once and in an instant became
| totally convinced that I understood the Ontological Argument
| perfectly and that it was 100% correct and undeniable proof of
| the existence of God. But then I lost it.
| 082349872349872 wrote:
| which of the many Ontological Arguments?
|
| (eg Godel's
| https://en.wikipedia.org/wiki/Godel%27s_ontological_proof#Ou...
| is an exercise in order theory, in which one proves that a
| certain axiomatically presented mathematical structure has to
| have a maximum, which then, for the religiously inclined, could
| be identified with God)
| mixmastamyk wrote:
| Not my click exactly, but hearing the "Unicode sandwich"
| described ~15 years after studying Unicode and using it in
| production was the last piece of the puzzle no one ever mentioned
| before. Or perhaps in not so clearly.
| user3939382 wrote:
| f(x) = y etc in linear algebra in school. By the time I was
| learning this in high school I'd already been programming for
| several years and perfectly understood the concept of function
| inputs and outputs. It wasn't until my early twenties that I
| realized this was just an alternate notation for functions and
| was so simple.
|
| Sad that my math education was just focused on "memorize steps"
| for concepts that weren't clearly explained.
| klysm wrote:
| The expression problem. I had vague notions of "horizontal" and
| "vertical" abstraction but they weren't concrete enough to
| discuss or make informed decisions about.
| djmips wrote:
| One of the big aha moments which clicked for me only fairly
| recently was staring at some physics equations my own
| internalized realization that light doesn't experience time and
| then I had to tell everyone haha - but that one eureka moment
| unlocked a whole lot of understanding and certainly a lot more
| questions. This of course was after all the schooling and physics
| where it somehow sailed over my head the whole time.
| [deleted]
| richardw wrote:
| I was going to put this as mine. It's astounding how important
| this is.
|
| I woke up at 2am with the intuition that light was like a
| lightning strike across spacetime, with no time and no distance
| between the emitter and absorber.
|
| Why and how, though. What are the fully-baked implications.
| peterfirefly wrote:
| I remember that we found that entirely obvious (well, most of
| us) in my high-school physics class.
|
| What I still don't understand, though, is how photons can
| "wave" or how "long" a photon is (or how they can have any
| "length" at all).
|
| What I also didn't understand back then was how light can be
| slower when there is matter present -- or how a photon could
| somehow know that it was supposed to cause another, very
| similar, photon to be released in just the right angle when
| it hit something that, if zoomed out enough, looked like a
| mirror. How on Earth could the photon know that the photon it
| was hitting was part of a flat surface and what its
| orientation was? I even started using that mirror question as
| a litmus test of physics students once I started at uni
| (comp.sci.) -- pretty much all of them failed, not by not
| knowing the answer but by not understanding that this was
| even a question that required an answer.
|
| I now know that the photon -- the wave(s) in the
| electromagnetic field -- cause atoms (and in particular their
| electrons) to move about a bit, which in turn cause waves in
| the electromagnetic field. And by adding up all these waves,
| we get the resulting wave which moves slower than c and which
| might seem to have been reflected at an angle. Why my physics
| teacher in high-school didn't tell us that, I don't know.
| 7373737373 wrote:
| I'm not sure how this works out in media which slow down light
|
| https://en.wikipedia.org/wiki/Cherenkov_radiation
|
| There, e.g. gravitational waves will be at c (in a vacuum), but
| wouldn't photons experience time there?
|
| Edit: I suppose the photons are still actually moving at c
| mattsears18 wrote:
| Functions in calculus... I never understood them until I learned
| about functions in programming several years later. They're the
| same damn thing! I really wish I had learned to program before
| learning calculus.
| peterfirefly wrote:
| Hopefully, you learned about functions long before calculus...
|
| When we learned about functions back in something like 5th
| grade, I noticed that my classmates were very confused by the
| concept. I also remembered that I found the explanations in the
| book and the ones from our teacher quite unclear.
|
| My guess back then was that the notation was partly to blame
| for that -- and I still think that's true.
|
| So, my questions to you are:
|
| 1) were you taught the "f(x) = 3x + 2"-style notation? 2) have
| you seen the "x --> 3x+2"-style before? Or the "f: x -->
| 3x+2"-style, where we give the function the name f? 3) did you
| find it confusing that f(x) was sometimes used to refer to the
| function and sometimes to its value when applied to x? The
| notation of question 2 should eliminate that confusion.
|
| I'm guessing that part of the confusion was also that your
| teachers were unclear on what functions could be used for --
| but didn't they ask you to draw graphs for various functions?
| And didn't they also introduce functions like sin/cos/tan?
| hammock wrote:
| >longer wires mean more resistance while thicker wires mean less
| resistance.
|
| Intuitively (perhaps incorrectly) I would assume that it's like
| trying to force a fluid through a skinny long pipe vs a wide pipe
| - the skinny long pipe will have higher pressure inside.
|
| Or, the long thin wire has more distance for the current to
| travel (= more resistance), while the thicker wire has more
| "options" for the current to choose a path of least resistance
| (literally), tending towards a lower overall resistance compared
| to a thinner wire of the same length
| richardw wrote:
| In OO, the interface. It seemed like the most useless construct.
| Zero implementation. Why make something with no implementation?
|
| Later I realised that the benefit isn't the code, it's the
| freedom you gain later in choosing the implementation. You can
| create an interface and add a simple implementation, then later
| swap it out for something more robust. All you're agreeing to now
| is the contract of what needs to be done, without any
| restrictions on how.
| ergonaught wrote:
| Basic music theory.
|
| Almost no one I encountered bothered to actually explain
| anything. They simply regurgitated things and I guess expected me
| to somehow intuitively understand something or other.
| parasti wrote:
| I recently learned what solfege actually is from a simple
| ChatGPT conversation after hearing about it for many years.
| myself248 wrote:
| Oh my god. Music and photography are my two pet peeves. They
| have their own twisted vocabulary for everything that surely
| exists for historical reasons, but might as well be purpose-
| built to obstruct polymaths from connecting their concepts to
| other concepts in other fields.
|
| My single largest goal when I'm teaching, is to find an
| appropriate analogy to a concept that my student already
| grasps, and bridge it to the new concept. Some fields make this
| super easy -- MechE and electronics, for instance, if you
| understand one, you're well on your way to understanding the
| other -- and some make it super hard.
| linuxlizard wrote:
| Sadly, mathematics classes are like that as well. Instructors
| start throwing equations on the board, expecting us to somehow
| connect it all together. The best math textbook (Theory of
| Algebra) I ever read had little sections about the person who
| revealed a particular subject, why they were studying it, and
| how the subject is used.
| luuuzeta wrote:
| Sadly many professors fall victim to the Curse of Knowledge.
| It doesn't help they need to follow a tight schedule and
| intuition isn't something you can develop in a single
| lecture. I suppose self-study and repetition is the most
| likely solution.
|
| >The best math textbook (Theory of Algebra) I ever read had
| little sections about the person who revealed a particular
| subject, why they were studying it, and how the subject is
| used.
|
| I've found the best type of books provide motivation for
| concepts, how they have evolved, etc.
|
| Take Computer Science for example, many of its concepts were
| area of research for decades but from a student's perspective
| it seems these concepts were always here instead of being
| constantly refined until the states they're now in.
| gen_greyface wrote:
| Do you remember what the book was called, or the writers.
| passion__desire wrote:
| I can't find the link. But I saw a minidocumentary about a
| person who trained his ears to listen to harsh noises. Once he
| attuned his ears, he could write music in those new musical
| notes.
| fooblaster wrote:
| Any good resources that do it the right way?
| ShredKazoo wrote:
| This site is nice https://www.musictheory.net/lessons
|
| Music theory is not inherently complex, but the notation adds
| incidental complexity -- it's sort of like the QWERTY
| keyboard; once you're stuck on a suboptimal way of doing
| things it's hard to move off.
| marmetio wrote:
| I've been using Punkademic and I'm very happy with it.
| amelius wrote:
| Looks like I have to pay before I can see what "Tools you
| will need to learn Music Theory quickly and efficiently".
|
| https://www.punkademic.com/course/music-theory-
| comprehensive...
| marmetio wrote:
| That's how a paid course works?
| amelius wrote:
| Yeah, but I'm not going to start a course if I don't know
| what tools and equipment I need for it, upfront.
| Myto wrote:
| Michael New on Youtube.
| sokoloff wrote:
| Systems in equilibrium. A lot of my college engineering courses
| had these (what seemed to me to be) hand-wavy assertions of
| equality and what seemed like just an assumption that the system
| would converge to that point.
|
| I was probably in my late 30s or early 40s before I really
| grokked _why_ that tended to be true. (I could blindly accept and
| grind through the equations to get the answers in college, but it
| was decades later that I developed a feel for _why_.)
| Overtonwindow wrote:
| Staying out of debt. A simple concept that took me until I was 37
| to appreciate and understand.
| djmips wrote:
| Yes, don't rent money unless you have a very good plan.
| vegetablepotpie wrote:
| UML
|
| When I first saw it, I thought it was a _process_ step that was
| unnecessary.
|
| Then I thought it was a way to program visually, but generated
| code only works in narrow domains.
|
| I realize that UML is tool to define your system, and it lays
| bare your assumptions, which is one of the hardest problems in
| computing.
| urthor wrote:
| UML is hard.
|
| Any abstraction can evolve into wasted time not making the
| thing.
| jonsen wrote:
| Recursion. I tried and tried and tried. Only when I untried the
| exact same number of times did it click.
| hospadar wrote:
| Voltage and amperage for me, years after a college electronics
| course and a childhood of soldering kits I finally started to get
| it. I was always tripped up with analogies about how it's like
| water in a pipe or something, which can be useful, but aren't
| quite right.
| clarkdale wrote:
| I would love to hear this in a way other than water in various
| sized pipes.
| marshmellman wrote:
| Can you share what helped it click? I'm in the same boat,
| trying to understand it through analogies.
| carapace wrote:
| These are physical properties that can be experienced
| (although there is some risk) for voltage you can touch a Van
| de Graaff generator, for current you can touch a battery to
| your tongue.
|
| That's the way to understand electricity without analogies.
| :)
|
| Anyway, voltage is always measured _between_ two points (one
| is typically called "ground" but that's not important here.)
| It's a difference. (A difference of what? No one knows.
| That's just the way it is.)
|
| Current is always measured through a single point. It's a
| count of the charge flowing past a point per time unit. (What
| is charge? No one knows. "Charge" is just a name for the
| mysterious something that "voltage" is a difference of...)
|
| When electricity moves it obeys a (very simple) Law called
| (Ohm's Law) e.g.: E = V/R
|
| The current (E) is the Voltage divided by the Resistance.
|
| E.g. is I have a 5 Volt power supply and I put a 100 Ohm
| resistor across it (remember that voltage is always between
| two points) then 5/100 Amperes of current will flow through
| it.
|
| Also, If I take just the resistor and drive 0.05 Amps through
| it, it will develop a voltage of 5 volts, as measured from
| one end of the resistor to the other end.
|
| Now if that doesn't help you, remember the advice of John Von
| Neumann to Felix Smith: "Young man, in mathematics you don't
| understand things. You just get used to them."
| rolisz wrote:
| Differential equations took a couple of years to grok. I first
| encountered them in high school, while preparing for physics
| Olympiad. I could solve basic differential equations by following
| the "rules" (such as for dampened oscilator), but I didn't
| understand what was going on under the hood. When in university I
| did some more math courses, suddenly differential equations
| clicked and made sense (and I could even derive some of the
| rules)
| atonse wrote:
| I failed calculus twice in college.
|
| Then a summer went by before the third time I took it.
|
| When I stepped into class that third time, everything clicked
| and it all felt very obvious to the point where I could
| anticipate where the lecturer's equations were headed.
|
| I stopped attending class and still got an A. I even ended up
| helping classmates in a study group.
|
| I still can't explain what that brain process was that resulted
| in the pieces subconsciously lining up over the summer.
| rramadass wrote:
| Any books you could recommend?
| I_complete_me wrote:
| Two are very pertinent for me at the moment:
|
| 1. The Monty Hall problem
|
| 2. The Wason Selection Task.
|
| I read about the first one eons ago and was impressed that
| Marilyn Von Savant was vindicated. Shoutout to her!
|
| The name Wason was unknown to me but I bought a book called The
| Oxford Companion to The Mind (new in 1987!) and his 'task' was
| featured in it (pg. 639 in my edition). I spent a lot of time
| satisfying myself as to the answer and kind of got there. This
| Christmas I am reading Stephen Pinker's "Rationality" and the
| description of both have allowed the penny to fully drop. I
| hadn't been thinking about these puzzles for ages and then when
| they cropped up "unexpectedly" I grokked them easily. They
| "clicked". There is a certain type of wisdom that comes with
| passed time.
| rubberband wrote:
| Oh thank goodness. Another human not cool enough to "get" the
| Monty Hall problem at first. I thought I was the only one...
| Took me years...
| sdenton4 wrote:
| Lie Groups... I signed up for a grad level course in my second
| year, and had no idea what was going on. Eventually I did my PhD
| on algebraic combinatorics, which works with Lie Groups quite a
| lot, but it took years to internalize all the ideas needed to
| have any intuition at all.
|
| https://en.m.wikipedia.org/wiki/Lie_group
| fooblaster wrote:
| Although I still don't understand liegroups with significant
| mathematical rigor, I do think I finally understand why they
| are used in code for computer vision and state estimation. It
| took me a shockingly long time to understand why.
|
| This paper was the catalyst to me finally grasping some of the
| details: https://arxiv.org/abs/1812.01537
| atemerev wrote:
| The relationship between entropy and states of matter (including
| pressure and temperature). How "degrees of freedom" are
| calculated and compared for gas molecules, if they are infinite.
| All that stuff.
| nmca wrote:
| The meaning of "adaptive" in the sense of evolutionary theory,
| and the capacity of species to evolve to extinction. Reading the
| selfish gene as a youth I missed the point; "an alien god" [0]
| and some Hanson articles got the point across finally.
|
| [0] https://www.readthesequences.com/An-Alien-God
| ruune wrote:
| Long time ago, but mathematical functions.
|
| In hindsight stupid, but it took me embarrassingly long to
| understand that a function just takes a value for x, calculates
| it with the rest of the numbers in the function and that way
| basically assigns a y-value to every x-value. No idea why it took
| me so long, I didn't have any similar problems with high school
| math
| W0lf wrote:
| Discrete mathematics and all sorts of its application in real-
| world (software development) related problems. Also how any given
| solution to a problem in one problem domain can be transferred to
| a problem in another unrelated domain. Think Galois theory but
| waaaay less fancy :-)
| philjohn wrote:
| When I did Mathematics A-Level's, we had to select four
| modules. I chose pure 1, pure 2, stats 1 and, new that year,
| discrete 1.
|
| So many useful groundings in various super important comp sci
| concepts.
| mablopoule wrote:
| "The road to hell is paved with good intentions.", "Perfect is
| the enemy of good", and more generally idioms that sound like
| either paradoxical assertions or obvious platitudes.
|
| It wasn't until late teens/early twenties that lots of those
| piece of wisdom went from "cliche phrases you've heard all your
| life", to (often) deeply impactful aspect of human conditions.
|
| The "road to hell" idiom explicitly didn't click until I had
| enough experience with counter-productive efforts who looks good
| on the outside, but actually fail to take into account a more
| nuanced reality.
|
| It also kinda works with the distinction between "values I
| believe in" and "arguments articulated around shared values".
| Being able to disagree on something even when (especially when)
| it's invoking values I believe in is one of the most important
| thing I've gained as I matured, and yet it needs experience to
| 'click'.
| jrockway wrote:
| I never remember the right "direction" for these platitudes. I
| feel like "good is the enemy of perfect" is just as valid as
| "perfect is the enemy of good". Meanwhile, the road to heaven
| is also paved with good intentions. Good paving material, it
| turns out, but asphalt is cheaper.
| [deleted]
| JanisErdmanis wrote:
| Superconductivity. I did four PhD projects regarding
| superconductivity properties at nanoscale without really getting
| hold on the concept. For instance, how zero resistance is related
| to cooper pair tunnelling and BdG Hamiltonian. Only when I was
| forced to write introduction a month before my thesis submission
| I gave my best last try for the farewell and it clicked. Note the
| title of my thesis "Quantum effects of superconducting phase" ;)
|
| Quantum computers. I was so deceived by all the hype that it took
| me long to see it as SU(N) matrix product accelerator.
|
| Zero knowledge proofs and Shamir transform to non-interactive
| protocol. The tunnel analogy did quite a harm to me, also the
| math was just unbearable (defining set of languages and etc).
| Only a year ago when I got an old paper on "Observational
| wallets" describing how to prove 'log_g A = a' and 'log_g A =
| log_g B' the whole 'proving statement without revealing secret'
| after long frustration and angst made sense to me. If I had
| encountered finding Vodo analogy first, It would have clicked
| much quicker to me.
| peterfirefly wrote:
| Old papers are great. I have often deliberately sought out old
| papers to get a quick and good introduction to a subject. It
| doesn't always work -- sometimes a newer paper with better
| abstractions/examples/terminology wins, of course.
|
| I no longer know when I figured out this trick, but I have been
| using it for at least twenty years. I wish I had known about it
| earlier.
| screye wrote:
| Related : I have a request for the 1 major concept that has never
| clicked for me --> Can someone help me understand 'productive
| value' in an economy ?
|
| I have tried hard, and can't for the love of me understand what
| lies at the bottom of trade, what is the base value of assets /
| activity. It just doesn't click.
|
| Questions like:
|
| - Can a services based economy work if the consumers of the
| services weren't producing some non-services based value ?
|
| - How can there be any economic value in middle-men ?
|
| - Is speculation on artificially limited assets (housing) just a
| pyramid scheme ?
|
| - How is it NOT a zero sum game ?
|
| - Is a Fiat currency just 'vibes based economics' ?
| bbayles wrote:
| Here's something to think about: suppose you buy an assortment
| of candy from the grocery store and distribute a uniform
| collection of pieces to a room full of middle school students.
|
| Some students will like the sour candy; others won't. Some will
| like coconut; others won't. Some will love nuts; others will
| hate them.
|
| Now you let the students talk to each other and trade candy.
| The ones who like sour candy but hate coconut will trade with
| the students with the opposite preference, and so on.
|
| At the end of the trades, everybody is happier with their new
| bundle - why would they have traded otherwise? So value has
| increased. But this is magic - no new candy was produced!
| Through trade we have increased overall value - the exercise
| was positive sum.
|
| With some effort you can see that a middle man might add value
| by expediting trades - connecting people who like coconut with
| people who hate it (suppose there are thousands of students in
| the class who all speak different languages).
|
| And you can see how fiat currency might make things easier.
| Rather than having to come up with the barter value of coconut
| candy and sour candy to nuts, you can convert both to a single
| unit and then trade units.
| db48x wrote:
| I can answer two of those. Middle-men are useful whenever there
| is fan-out or fan-in. A producer wants to sell to consumers, so
| there is a lot of fan-out. The producer could get the consumers
| to come to the factory and to buy good directly, or they could
| go door to door, or they could use middle-men: retail stores.
| The stores buy the goods wholesale and take on the work of
| selling them to individual customers, in exchange for a portion
| of the total profit. Customers visit stores for the same
| reason, to avoid having to visit every factory for every
| producer of the goods they want. With time and effort saved on
| both sides, the stores benefit both the producers and the
| consumers.
|
| The economy is not a zero-sum game because we are summing the
| value, not the prices, of the goods that are traded. If I grew
| wheat and you grew apples, then we can trade between us to
| mutual advantage, because after the trade we can both make
| apple pie (assuming we can find some cinnamon). The total
| amount of wheat and apples hasn't changed, but their value has
| gone up. Every trade involves two parties who must both believe
| that they will gain value by the trade. Of course it is
| possible for either party to be mistaken (or even deliberately
| swindled by the other party), but as long as the majority of
| trades have net positive value then the economy as a whole will
| be a positive-sum game.
| xvedejas wrote:
| I can try some of these
|
| > Is a Fiat currency just 'vibes based economics' ?
|
| I'd think of it more like contract-based/trust-based. If a
| government has promised you can pay your taxes and debts in a
| fiat currency, and you believe them, then you'll value that
| currency. You may need it some day. When the trust erodes, so
| does the value. I don't think this is simply "vibes", it's
| people behaving rationally about what they expect the future to
| hold. And in fact this is just what "value" means for all
| things generally. Someone thinking rationally about how to
| value a gold-backed currency is still asking themselves whether
| they expect gold to be worthwhile in the future.
|
| > How is it NOT a zero sum game ?
|
| A zero-sum game would be one where there's just a fixed amount
| of value to allocate however, and you're stuck to the pareto
| frontier; that is, there is no re-allocation which would leave
| someone better-off and nobody worse-off. But in reality there's
| obvious misallocation all of the time! That's why you would
| ever buy or sell something: because two parties both believe
| they benefit from that exchange. Whether that exchange is
| actually positive or negative for society depends on
| externalities. But it seems pretty clear to me that a lot of
| activity is a negative-sum game (if it cause pollution,
| addiction, etc), and a lot of activity is a positive-sum game
| (most other things), and almost nothing is actually zero-sum.
| How is it NOT NOT a zero sum game?
|
| > Is speculation on artificially limited assets (housing) just
| a pyramid scheme ?
|
| Kinda.
| theptip wrote:
| Domain Driven Design. The book by Eric Evans lays out a bunch of
| concepts and as a developer that had not owned the architecture
| of a big domain, it was hard for me to see exactly where they
| fit. But after reading the book a couple times, and then
| encountering a few tricky domain modeling challenges, I started
| to see where these patterns add value. Also, as I started trying
| to describe the cohesive domain architecture of the system to a
| growing engineering organization, I also clicked on the advantage
| of having a standardized set of terminology for the problem,
| rather than inventing your own. It's nice to be able to link to
| an existing explanation of what a Repository is for, instead of
| having to name and document your own ad-hoc architectural
| patterns (or more likely, end up with you ad-hoc architecture
| being under-documented).
|
| Things like Repositories, Aggregates, Bounded Contexts, and so on
| are going to be a net drag on your system if you only have a few
| 100 kloc of code in a monolith. But they really start to shine as
| you grow beyond that. Bounded Contexts in particular are a gem of
| an idea, so good that Uber re-discovered them in their
| microservices design: https://www.uber.com/blog/microservice-
| architecture/.
|
| (Edited to clarify the book author)
| danielvaughn wrote:
| The terminology really turned me off because I found it
| difficult to comprehend. But I loved the idea of ubiquitous
| language and always meant to return to the book and give it
| another shot.
| theptip wrote:
| Indeed, some of the names are just bad; "Anti Corruption
| Layer" is actually a quite useful concept for explicitly
| translating between concepts in different Bounded Contexts
| (do the translation explicitly at the edge so the mappings
| between BCs are explicit, instead of mixing terminology), but
| man I feel like something more snappy could have been used.
| eckza wrote:
| It's a solid book. I was chugging through it a bit at a time,
| until I discovered Scott Wlaschin's Domain Driven Design Made
| Functional. I've dropped the Evans book (as it's mired in
| mid-00's Enterprise Java patterns) and am enjoying this one
| quite a bit more.
|
| Both books are great. Read whichever one aligns with your
| practice best.
|
| I recommend Wlaschin's book for anyone curious about FP,
| without hesitation. He's great at explaining things from first
| principles, without veering off into "monad tutorial"
| territory.
|
| https://pragprog.com/titles/swdddf/domain-modeling-made-func...
| theptip wrote:
| Thanks, I hadn't seen that book -- will give it a read. I'm
| interested to see how DDD gets applied to the functional
| programming paradigm, as it seems quite deeply ingrained in
| OOP to me.
| cpeterso wrote:
| Evan's book is a bit of an academic slog, but I finally felt
| like I understood how object-oriented design should work.
|
| An easier introduction I recommend is InfoQ's "Domain Driven
| Design Quickly", available in print or a free PDF ebook:
| https://www.infoq.com/minibooks/domain-driven-design-
| quickly...
| shortlived wrote:
| This is the book by Eric Evans?
| theptip wrote:
| That's the one. (I edited in a clarification to my original
| post.)
| feoren wrote:
| I had the exact opposite reaction to this book. It seemed like
| great stuff when I first read it, but over time, I realized
| it's really misguided in a lot of ways:
|
| - Aggregates are too heavy. You need to make the decision about
| what is or is not an aggregate way too early in the design
| process. Boundaries are fuzzy.
|
| - Actual concepts don't exist in nicely packaged bounded
| contexts. Concepts overlap a lot. You need to make the decision
| about which concept fits into which bounded context too early
| in the design process. Boundaries are fuzzy. Things are kinda
| like other things. The definition of "Employee" is not the same
| in the Scheduling context as the HR context as the Payroll
| context, yet they do overlap a lot, and you can't just treat
| them as completely separate things. If you break everything
| down into tiny contexts to deal with this, you just make
| Contexts and Aggregates the same.
|
| - Repositories are not original to DDD and I think are very
| likely to foster absolutely horrific SELECT N+1 or even SELECT
| N^2 or N^3 performance. You simply can't let one bounded
| context do all its expensive operations in a vacuum; not when
| you have lots of contexts and lots of operations. In a complex
| system, most parts need to be _planning_ , not _doing_. The
| results of most operations should be a plan that you can
| compose with other plans, analyze, and possibly even have an
| "optimization pass" if you need one.
|
| - Ubiquitous language is the right idea. If you take nothing
| else from DDD, take this.
| theptip wrote:
| Fair enough; YMMV.
|
| I've not found that Aggregates need to be designed at the
| beginning; I've found it works fine to define an Aggregate
| after you start seeing performance issues with query patterns
| (i.e. define an Aggregate and forbid direct access to sub-
| objects when you see pathological access
| patterns/deadlocking).
|
| Personally I've found Repositories to be a good way of
| enforcing that N+1 queries DO NOT happen. For example, in
| Django you can have the repository run
| select_related/prefetch_related and `django-seal` on the ORM
| query to forbid unexpected queries. This somewhat neuters the
| flexibility of the ORM, which can be a big cost, but lets you
| build much more restrictive queries that are guaranteed to
| perform well. It's a trade-off and I don't think it's a clear
| win for every use-case, but particularly when dealing with
| Aggregates I think having a limited number of ways to query
| is beneficial. (This might mean you're running some sub-
| optimal SQL queries, over-fetching etc., but for most line of
| business applications, that's actually a viable trade in
| exchange for simpler domain interfaces and protection against
| N+1 queries.)
|
| Regarding "planning" vs. "doing", that seems to fit quite
| well with doing most of your work in POJO/POPO domain models,
| then only rendering those into DB writes at the edges. I
| think Repos can help with that. (IME you get N+1 selects when
| you use ORM models that abstract away the SQL queries and
| have application code interacting directly with ORM models;
| if you remove the ORM from your core domain logic and force
| it to live at the edges in Repos, this is not possible.)
| feoren wrote:
| I suspect these different design "paradigms" all look
| somewhat similar when done really well and thoughtfully,
| but tend to have different gotchas and failure modes. Happy
| vs. unhappy families and all that. The worst design
| decisions we've seen are very salient in our minds, and
| these bad decisions are more shaped by the paradigm than
| the good ones are, so they look like the fault of the
| paradigm. Therefore we tend to compare paradigms based on
| how they go wrong, and people see bad design and think "wow
| we need a new paradigm". In that sense: YMMV indeed, and if
| DDD works for you, go for it. It's definitely worth
| learning, even if only so you can disagree with it! There
| are a lot of good smaller points in the DDD book even if
| you disagree with the larger paradigm.
|
| As an example, when I think "Repository", I think a class
| with methods like "GetEmployee(employeeId)" that hit the
| database immediately, and probably call other
| GetSingleThing methods in other repositories, possibly in a
| loop. That's how you get SELECT N^2s and up. That is, of
| course, their worst possible use, and you can have much
| better-thought-out services and still call them
| "repositories".
|
| That all being said, there _are_ some near-universal "good
| ideas" I've learned, but they probably don't make a good
| textbook, and they certainly don't make a singular
| "paradigm" to follow. Things like: make decisions as late
| as possible (but no later). Do less, plan more ("do"
| meaning something with a side effect; planning is side-
| effect free). Work with sets instead of individuals.
| Separate identity from data. Raise the ceiling (empower
| smart people), not the floor (don't design for stupid
| people), but also realize that everyone is both sometimes.
| I use these general rules to evaluate paradigms, and I
| think DDD strongly fails the "make decisions as late as
| possible" rule, and doesn't tend to foster the "do less,
| plan more" rule unless you really reinterpret a lot of its
| directives.
| theptip wrote:
| I strongly agree with the general principles you're
| putting forth, and agree it's hard to build an
| architectural philosophy which bakes in "good sense" as
| well. To some extent these can be orthogonal. (At the
| very least, your architectural philosophy had better not
| be opposing good sense, but I think it's fine for the
| philosophy to not encode every best-practice of good
| sense.)
|
| > all look somewhat similar when done really well and
| thoughtfully, but tend to have different gotchas and
| failure modes.
|
| I do agree with this to an extent, although I also think
| that "what does this theory tell me to do that differs
| from some other theory" is a quite valuable question; I
| do think there are some structural aspects of DDD which
| could be "bad" in other approaches.
|
| Perhaps most obviously, the meta-approach of having well-
| known named concepts in your architectural framework is
| in some sense opposed to the "pragmatic design" or
| "framework-less" approach of just using good taste and
| experience to come up with the right design for each
| situation. The latter perhaps being "better" for
| experienced architects, but harder to teach IMO.
|
| > when I think "Repository", I think a class with methods
| like "GetEmployee(employeeId)"
|
| Not to beat a dead horse, but on this object-level point
| -- in my understanding DDD explicitly contemplates both
| singular fetches like `GetEmployee(employeeId)` and
| plural like `GetEmployees(createdAfter)`. I think the
| book (Evans, 2003) has examples of each (though I could
| be mis-remembering and drawing from some of the other
| practical DDD-by-example books).
|
| But I can see where a team might use a sub-optimal
| combination of existing Repo queries rather than writing
| their own new ones.
| jethkl wrote:
| The axiom of choice, Tychonoff's theorem, and the open mapping
| theorem [0, 1, 2]. Each one took me, in my view, much too long to
| grasp.
|
| [0] https://en.wikipedia.org/wiki/Axiom_of_choice
|
| [1] https://en.wikipedia.org/wiki/Tychonoff%27s_theorem
|
| [2]
| https://en.wikipedia.org/wiki/Open_mapping_theorem_(function...
| kccqzy wrote:
| The axiom of choice is the topic of one whole quarter of set
| theory in my undergraduate years. I still don't think I fully
| understand it. By "fully understand it" I mean achieving the
| level of proficiency of my professor who, upon hearing
| seemingly any theorem encountered in undergraduate study, would
| immediately tell you whether it requires Axiom of Choice,
| merely Dependent Choice, Countable Choice, or doesn't require
| Choice.
| evanpw wrote:
| This is true of almost everything in math. You learn some
| definitions and techniques in one class, and it doesn't all
| become clear what's going on until you've used those to as the
| base layer for solving some other problems in the next class.
| Part of it is just that it's hard to teach you need the first
| concept in order to understand the second, but you need the
| second to understand why you should care about the first, so it's
| all a bit circular.
| recursivedoubts wrote:
| i didn't really understand hypermedia, and, in particular, the
| uniform interface/HATEOAS until a few years after i started
| building intercooler.js (htmx predecessor)
|
| https://intercoolerjs.org/2016/01/18/rescuing-rest.html
|
| much later:
|
| https://htmx.org/essays/hateoas/
| NeutralForest wrote:
| I'm reading the HyperMedia book right now, thanks!
| shrimpx wrote:
| I studied functional programming and I took terms like
| "expression", "evaluation", and "value" for granted until it
| clicked that these terms have intuitive meaning when interpreted
| in colloquial/human terms.
|
| - Expression as in someone expressing themselves, a tentative
| gesture.
|
| - Evaluation as in scrutinizing something to learn what it's
| really about.
|
| - Value as in "valuable".
|
| We don't know if an expression is valuable until we subject it to
| evaluation, or we get an interpreter to interpret it for us.
| dehrmann wrote:
| Have you ever studied compilers? You'll gets a good idea of
| these concepts from a toy compiler for an imperative language.
| olalonde wrote:
| It took me a long time to grasp market economics. I knew it
| worked somehow but I didn't quite understand why. What really
| made it click was Milton Friedman's "Free to Choose" TV
| series[0].
|
| [0]
| https://www.youtube.com/watch?v=dngqR9gcDDw&list=PLXD32Z5YYi...
| sowbug wrote:
| Taking the point of view of others, and learning to view a
| situation from a "perspective-less perspective."
|
| It's easy to think you have people skills because you listen to
| others and repeat their point of view back to them before telling
| them they're wrong. And unfortunately you can get quite far in
| the business world simply by being good at demolishing other
| people's positions.
|
| As a mental exercise, a few years ago in meetings I started
| deleting the names from the running transcript I keep in my head.
| "Joe said X and Jane said Y and then I said Z" was replaced with
| "we said X, then Y, then Z." It was a remarkably effective device
| to rise above the "who's going to win?" attitude and instead
| think about the best way for everyone to proceed as a group. I
| suddenly started to get what people say about meditation and
| removing the "I" perspective from your life. If instead of being
| you, you're a quadcopter hovering near the person you call
| yourself, it's so much easier to get your ego to shut up and
| start listening for once.
| nathias wrote:
| mine is the opposite, you can't get anywhere in life with the
| perspectiveless perspective
| sowbug wrote:
| Maybe it works best as a blend of looking out for yourself
| and looking out for the group.
|
| Or, cynically, maybe it's effective to adopt the group-first
| mentality once you have the personal momentum from years of
| being self-centered.
| hyperthesis wrote:
| observe selflessly, act selfishly
| college_physics wrote:
| Graph theory. For the longest time I thought it is an interesting
| and even beautiful branch of mathematics but somewhat
| "recreational" and disconnected from my various bread-and butter
| workhorses for applied work (from linear algebra and PDE's to
| differential geometry etc). So I never bothered to dig and
| connect the dots.
|
| At some point I realised the connections between the two worlds
| e.g., graph operations as linear algebra [0] or the transition
| from continuous Laplacian to graph Laplacian via a discrete
| Laplace operator [1]
|
| [0] https://graphblas.org/
|
| [1] https://en.wikipedia.org/wiki/Discrete_Laplace_operator
| dqpb wrote:
| Data structures are more interesting than algorithms.
| anacleto wrote:
| Krebs cycle.
| ISL wrote:
| That professors were thinking real hard about which problem sets
| to give us in hopes that we would actually learn something.
|
| I don't think I really understood that completely until I started
| TA-ing.
| luuuzeta wrote:
| Tangentially related but that's something I've come to realize
| too as of recent. Asynchronous programming in JavaScript is new
| to me so as an exercise, I'm writing a document where I explain
| the concepts to myself and once I shifted from "how I
| understand" to "how I would this to someone else", figuring out
| a good enough scenario/problem harder.
|
| Good problem sets that aid studets' intuition aren't easy to
| come by, oftentimes they're either too easy or too hard.
| throwaway81523 wrote:
| The purpose of C++ template generics only made sense to me after
| I started using Haskell.
| rrgok wrote:
| I have to agree. I couldn't understand templates until Haskell
| introduced me to it. But Haskell is expressive enough that the
| intuition comes naturally.
| hawski wrote:
| Parenthood. Now I see how much my mom was right, but couldn't put
| things in proper words.
| CSDude wrote:
| Sadly, React. Was using Angular 1, and Vue made much more sense.
| I'm not a Frontend Developer though, but needed to learn React
| but it happened to late. At least, when I needed to learn,
| components were not classes anymore but functions which made
| learning curve somehow simpler for me although its not much
| difference.
| lebaux wrote:
| theory of reliativity, took me a while, but now I think I got the
| main gist
| 7373737373 wrote:
| I'm not sure if this even possible, but I'd appreciate a
| "relativistic simulation for dummie programmers" handbook
| throwaway98797 wrote:
| blockchains as a single source of truth
|
| always seemed like a shitty expensive database for 7+ years
| pintxo wrote:
| What made you believe that they are not a "shitty expensive
| database" after all?
| throwaway98797 wrote:
| in the ecosystem of a single blockchain, they are the single
| source of truth that is an open api-like thing that no
| company _can_ control
|
| therefore it's safer to build then on twitter, facebook,
| apple, etc.
|
| the entire ecosystem _may_ be a fraud, but if it is not then
| it's incredibly enduring. i have more faith that i can get
| what the balance of an account is in 10 years from ethereum
| than i do from my banks api staying stable or open.
| amorroxic wrote:
| the null concept being referred to as "the billion dollars
| mistake" - until discovering optionals and gradually opening up
| to FP, category theory, etc
| bazoom42 wrote:
| The "billion dollar mistake" was not the null concept itself,
| it was having all reference types be nullable, i.e no
| distinction between nullable and non-nullable in the type
| system.
| pfoof wrote:
| The importance on clean code, architecture and testing. That was
| during my university when we had a serious diploma group project
| on the last semester.
|
| Also importance of reading books even later. My mother told me
| this all the time but school books were not the best choice. In
| high school I started reading fanfics, then occult books and
| finally I landed on self-helps and ones related to my SWE career.
| machina_ex_deus wrote:
| Learning history / literature in school is important.
|
| I was a total STEM math nerd in school. I used to frequently
| complain how I don't get what's the point of it, or how it's a
| waste of time and I'm learning nothing. I still think the
| emphasis of school was off, but I get the point of it now.
|
| Stories are like code for humans. You can't tell someone what it
| means to be good or bad, or to give them a course in philosophy
| and they will become good people. But you can tell them a good
| story, that engages with them emotionally, and it will change
| their perception. And history shows that in fact, those stories
| being told and repeated aren't just interesting minor curiosity,
| but they have shaped the direction of humanity and they are
| driving it. A single person with a single story can change
| history in such a way that it would be completely different
| without it. And some stories about stories need to be told as a
| warning so that people will not fall for those kinds of stories
| again.
| satvikpendem wrote:
| Regarding literature, I'll give an opposite opinion. Being
| forced to read the classics in school led me to not caring
| about them at all because I just couldn't relate at all, I had
| not had the requisite life experience for them to make an
| impact on me. Now, being an adult and having the life
| experience, reading them again makes me think more deeply and I
| can actually relate. So I think in school, we actually
| shouldn't read high literature lest we hate reading them as
| adults, which is really when they should be read, not before.
| josephcsible wrote:
| I agree in general, but for me it wasn't so much just having
| to read them as it was having to do a bunch of silly
| assignments based on them. My high school completely ruined
| The Great Gatsby for me that way.
| thewebcount wrote:
| I was fine with literature, but yeah, history, what a snooze-
| fest. Why do I care who fought what war 1,500 years ago and who
| won? It seemed like it mostly came down to a bunch of pompous
| elites having dick-measuring contests a lot of the time.
|
| Then one day the teacher didn't want to teach and instead
| showed an episode of Connections, and I was blown away.
| Learning about how and why our science and technology became
| what it is was something I could related to and seemed actually
| useful. I still don't care for military history, though.
| 9804 wrote:
| I think people come out of school hating reading because nobody
| likes being forced to read specific books, as everyone's tastes
| are different. It sounds like this might have been what
| happened to you.
| mabbo wrote:
| I completely agree with this. I loathed Shakespeare in
| school. Now I try to get a visit every year to the Stratford
| Festival (in Stratford, Canada) to see at least one or two
| Shakespearean plays.
|
| I also remember reading 1984 on my own time in high school-
| it wasn't in the curriculum the year I might have. It blew me
| away. But if I'd been forced to read it, I probably would
| have been bored.
| Balgair wrote:
| For other HN readers:
|
| I was like this too. I had no interest in ol' Bill. Then I
| read his 'best' works. And then I read them again. It takes
| a bit to get really used to iambic pentameter, to the old
| words, to the places and people he was writing for, to his
| limitations of candlelight and lack of amps, etc.
|
| Reader, _it is totally worth it_.
|
| There are very many very good reasons that he is still
| produced and studied. I encourage you in this new year to
| give him a solid try. Not just a play or two. Read him and
| watch the plays at the same time. There are hundreds of
| productions on YT for every play of his, all free, most
| very good.
| machina_ex_deus wrote:
| I never hated reading, it's just that I didn't get the point
| of it. What are we even doing here and why?
|
| What's the point? Math has clear purpose. I do enjoy some
| books. I just didn't get the point of studying them beyond
| reading. Why are they babbling about ? Is there any use for
| this information or is it just a torture in memorization? Why
| would I ever care about all these abstract literature terms?
|
| Ironically they missed telling the meta story: why would
| anyone care about stories.
|
| If stories are just something you read for fun, why would
| anyone care to teach me how to analyze them?
|
| EDIT: To be clear, these were the questions that weren't
| answered back then.
|
| Only now, years later with life experience the purpose is
| clear.
| [deleted]
| dehrmann wrote:
| My issue was the volume we were expected to read, or at least
| volume on top of books I wasn't interested in reading.
| ahmadnoid wrote:
| That sometimes the extreme needs to manifest in order to pull
| toward the middle
| DylanSp wrote:
| Matrix multiplication. First encountered it in high school, where
| the textbooks presented matrices without any real motivation, and
| matrix multiplication just seemed like a weirdly-defined
| operation. Once I got to linear algebra in college and matrix
| multiplication was presented as the way to compose linear
| transformations, it made a lot more sense.
| Jasper_ wrote:
| The easiest way to describe matrix multiplication is nested
| function composition. f(x) = 2x g(x)
| = x + 5
|
| It should hopefully be obvious that "nesting" the two isn't
| commutative: g(f(x)) = (2x) + 5 = 2x + 5
| f(g(x)) = 2(x + 5) = 2x + 10
|
| One miraculous fact here is that no matter how many functions
| we stack, we only ever have two terms: x and a constant term.
| Thus, we can represent this 'linear system' in terms of its
| coefficients, as long as we agree on an order: e.g. 2x+5 might
| become "2,5" in our system.
|
| You can do "multiplication" on these packs to compose them
| together, and even though the rules feel obtuse in abstract,
| they follow the logic of function composition. A matrix
| represents a similar function transform, only it's in 3
| dimensions, and in order to handle rotation, it needs to swap
| around x/y/z. So an identity matrix is really saying:
| f(x) = 1x + 0y + 0z + 0 f(y) = 0x + 1y + 0z + 0
| f(z) = 0x + 0y + 1z + 0
| [deleted]
| Sharlin wrote:
| Matrices are funny. You can encounter them as a teenager
| reading 3D graphics tutorials on the internet, learn that they
| can compactly represent scalings, rotations, and translations,
| and that several transformations can be conveniently "stacked"
| using this thing called matrix multiplication which looks like
| this... and that's it, now you can use them for a cool
| practical purpose, but the tutorials never derive or attempt to
| justify _why_ mmul looks like that, often because the author
| doesn't know either!
|
| Or you can learn about them in school and be given neither a
| real-world use case nor a rationale or derivation for mmul.
|
| Or you can encounter them in college, and there the experience
| depends on whether it's a good or bad kind of a linalg class.
| But even there - after all the painstaking definitions and
| lemmas and derivations - it's easy to end up not grokking _how_
| mmul does what it does _even_ if you grasp all the building
| blocks - vector spaces, bases, how matrices can represent bases
| _and_ systems of linear equations _and_ linear operations on
| vectors _and_ how they're all kinda equivalent.
| boricj wrote:
| It reminds me of a funny story back when I was a student.
|
| We had a week-long group project in the first year whose
| theme was "a 360deg pong". Our group decided that it meant
| the paddles had to travel in a circle around the playfield
| and I've decided that matrices and stacked 2D transformations
| were the way to go. The other students gave me blank stares,
| I basically said "trust me, you don't need to understand them
| to use them" and off we went coding.
|
| We ended up with the most impressive pong clone out of all
| the groups, as nearly all of them had axis-aligned
| rectangular paddles going around a rectangular path, whereas
| ours had a stretched half-circle paddle going around a circle
| path always facing the center of the playfield, alongside
| extra features like walls and a level editor.
|
| First class the Monday morning after, the math teacher
| announced that the next topic was matrices. We stared at each
| other in the group and grinned manically.
|
| If anyone wants to stare at an old C codebase from 10 years
| ago by a bunch of first year students:
| https://code.google.com/archive/p/pong-norris/
| aj7 wrote:
| And a lot of dynamics is e to a matrix.
| rkp8000 wrote:
| A big one for me was realizing that a matrix times a vector
| returns a weighted sum of the matrix columns, with the vector's
| elements as weights. It's not particularly profound but it has
| definitely clarified my intuition around a number of matrix
| problems.
| enkid wrote:
| It took me taking a class in neural networks in my thirties to
| really understand matrix multiplication
| jliptzin wrote:
| Which class?
| enkid wrote:
| It was Andrew Ng's machine learning class on Coursera
| thamer wrote:
| A sibling comment to your mentioned Andrew Ng's class, and
| I actually had the same experience as them with the same
| class. You can find it by searching for Stanford CS229; the
| lectures are available on YouTube.
| arcturus17 wrote:
| I did a fairly rigorous linear algebra course in school, and
| it went over my head despite passing it.
|
| Saw it explained in a single slide of Andrew Ng's ML course
| and everything clicked perfectly.
|
| Where I lived math was taught like fucking shit, it was all
| algebra and zero context as to why it could be useful in
| real-life scenarios, zero abstraction such as visualization
| or metaphor. Everyone involved in concocting that pedagogic
| aberration should feel terrible about it.
| enkid wrote:
| The Coursera one? That's the exact course I was thinking
| of.
| bgoated01 wrote:
| Linear algebra in general for me was kind of one of these
| concepts. Aced my university linear algebra class with no idea
| what the heck I had learned. It didn't start to click for me
| until I started using it for tangible problems.
| divbzero wrote:
| Matrix multiplication is the first example that came to mind
| for me too. I learned it as compositions of linear
| transformations (the professor "taught" it through a question
| on the take-home final) but it felt abstract to me and took
| years to become intuitive to the point where I could actually
| explain it from scratch.
| leftcenterright wrote:
| Visual thinking! [1]
|
| I had read a bit about different types of thinking but I didn't
| really understand it so well until I saw a kid who had amazing
| visual thinking capability and could visualize years' old
| memories in a very detailed manner. It has also been related to
| photographic memory according to some research.
|
| [1] https://en.wikipedia.org/wiki/Visual_thinking
|
| Nikola Tesla's Creative Thinking Secrets: https://www.sers.si/wp-
| content/uploads/2014/10/angle%C5%A1%C...
| satvikpendem wrote:
| You should read Moonwalking with Einstein and look into memory
| palaces. I have memory palaces I can still walk through and
| remember after a decade.
| zenmacro wrote:
| Central Banking 101 by Joseph Wang does a great of explaining the
| repo and reverse repo markets.
|
| https://books.google.com/books?id=wPs_EAAAQBAJ
| robg wrote:
| The autonomic nervous system and the adrenal cortex. Homeostasis
| is taught as a textbook fact, the body reverting to a baseline
| over time. What's not taught is how much the impacts of daily
| life events drive a continuous stress response. Fight or flight
| is not just a reaction to deadly threats. It's active every
| moment of every day to ensure survival. The adrenal cortex is
| always active, to traffic, your boss and colleagues, relationship
| struggles, and overall health and wellness like sleep and
| nutrition. Yes, the system reverts to a baseline over time but
| how much that baseline varies is obvious in tracking resting
| heart rate.
| rramadass wrote:
| Any books you could recommend?
|
| I presume you already know of this book: _The Body Keeps the
| Score: Brain, Mind, and Body in the Healing of Trauma by Bessel
| van der Kolk._
| robg wrote:
| That's a great one. I've been looking for something that
| links the physiology with knowledge work and life demands,
| but I haven't found it yet.
| sirsinsalot wrote:
| Thank you. Bought and reading.
| rzzzt wrote:
| "Understanding Stresses and Strains" from 1968 presents a good
| depiction of the mechanism with familiar-looking cartoon
| characters:
| https://archive.org/details/understandingstressesandstrains
|
| The caveman pressing the alarm button is something I think of a
| lot.
| jefftime wrote:
| For me it was pointers. I used C throughout college and I never
| really grokked the "address to a value" description, but one day
| it finally just clicked and now I love pointers
| hakanderyal wrote:
| Power of static typing, that it allows one to develop complex
| programs faster and better, not slower.
| klysm wrote:
| I think the develop faster thing is a poor argument for static
| typing. The refactoring piece of the equation is the most
| important to me. Static types provide confidence (and speed)
| while making sweeping changes to code.
| hakanderyal wrote:
| That's what I meant by developing faster. Refactoring is an
| indispensable part of the building process.
| klysm wrote:
| Yeah totally agree that refactoring is part of development
| but I don't think people frequently think about in
| comparison to maintenance.
| rramadass wrote:
| The use of Predicate Calculus in coming up with the Proof along
| with the Program.
|
| Predicate Calculus is used to show that the path followed by a
| Process through a Cartesian Product space (created from all the
| memory variables in a Program) is the one you had in mind w.r.t.
| its Specifications. Suddenly you start to understand basic Set
| Theory, Types, Relations (Functions) and Logic.
| linuxlizard wrote:
| Blue Noise dithering based on a HN post from @todsacerdoti.
| https://news.ycombinator.com/item?id=25633483 At my previous job
| we had an ASIC hardware block to implement blue noise dithering.
| No one, even the people who created it, could explain to me how I
| needed to use it. Years latter, I read their blog post and a
| light bulb went on.
| whacked_new wrote:
| I love this as a research topic. Here are a few examples close to
| me.
|
| 1. The nature of variance in regression methods. The first time I
| heard about "soaking up the variance" in modifying stat models in
| brain imaging I had no idea what was going on. Then I spent a few
| years doing brain imaging and modified models to "soak up the
| variance" differently. Over the few years I came to grok the
| concept. I had a electrical engineering PhD colleague with an
| impressive resume who would argue with me about the effects of
| models. I realized that he knew the textbook stuff (which I
| didn't), but he didn't actually grok the concepts (which I did).
|
| 2. Once in an office was I mystified by hot spots and cold spots
| of wifi signal. One of my colleagues, a brilliant engineer, then
| explained to me what might affect the shape of the hot and cold
| spots, which is why he sits in certain places. I asked him if he
| had an intuition of how RF fields are distributed and he said
| yes, so I asked him how. He said, "I used to do a bit of tensor
| calculus".
| jeffreyrogers wrote:
| I used to work in an office where I only got cell service on
| cloudy days, I assume it had something to do with the clouds
| reflecting the signal.
| tobyhinloopen wrote:
| Shaders.
|
| I tried shader tutorials multiple times for years and they only
| started to click recently.
| baby wrote:
| Any good resource on that? Bonus if it's for Unity
| mmcconnell1618 wrote:
| Ben Cloward - Shader Graph Basics for Unity - https://www.you
| tube.com/watch?v=OX_6_bKpP9g&list=PL78XDi0TS4...
| fortituded0002 wrote:
| 1. Everyone is the main character in their own story.
|
| This manifest in all sorts of ways - from people not being there
| when you need them the most, from friends dying off as soon as
| proximity changes, to how and why get people get promoted in
| jobs. This isn't necessarily bad, but if you don't know how to
| navigate this it can be quite painful and confusing.
|
| 2. Representation matters.
|
| I knew this for a long time, but it didn't fully click until
| years had gone by and I realized I had unconsciously held myself
| back from pursuing a wide range of things because I just didn't
| see anyone like me there.
|
| 3. Rules in life are just constructs that we as humans have
| created.
|
| Starting a business helped the most on this one. That's when I
| started to see that "rules" or "procedure" are all made up and
| exceptions can always be made.
|
| (Edit: typos)
| throwaway1777 wrote:
| #1 is a fallacy called main character syndrome
| jackthetab wrote:
| Any suggested reading for #1 ("learn how to navigate \$THIS.")?
| texuf wrote:
| It's old and perhaps a little controversial, but " NLP: The
| New Technology of Achievement" has good examples and
| abstractions that could help you with #1
| icepat wrote:
| Controversial in that it's generally considered a
| pseudoscience. I'd advise against anyone looking to figure
| out how to navigate this wasting their time with
| pseudosciences.
| carapace wrote:
| > it's generally considered a pseudoscience.
|
| Only by people who have no experience with it.
|
| NLP ("Neurolinguistic Programming", not Natural Language
| Processing) is _pre-scientific_ , yes, but that's not the
| same as being a pseudoscience, and calling it such is a
| disservice.
|
| We have pretty much discovered the operating system of
| the human mind. applying the principles and techniques
| discovered and systematized under the rubric of NLP one
| can do amazing things.
|
| - - - -
|
| It is strange that academic research psychologists seem
| to have trouble with it. But that's their problem, it
| doesn't change the fact that people all over the world
| are learning and using this stuff every day. If academic
| psychologists can't understand it that just makes them
| irrelevant, it doesn't change the facts.
| concordDance wrote:
| > 2. Representation matters.
|
| As a well represented person I can tell you this has nothing to
| do with representation, its just that the vast majority of
| humans in the modern world have close to zero agency and/or
| don't think they can actually change things.
| DrewADesign wrote:
| > _As a well represented person I can tell you this has
| nothing to do with representation, its just that the vast
| majority of humans in the modern world have close to zero
| agency and /or don't think they can actually change things._
|
| As a well-represented person, you're _probably_ making
| assumptions about the effects of representation that are less
| informed than you realize.
| jahnu wrote:
| Regarding #3, the following David Graeber quote always stuck
| with me:
|
| "The ultimate, hidden truth of the world is that it is
| something that we make, and could just as easily make
| differently."
| tootie wrote:
| Sapiens by Harari covers this extensively. So much of human
| development is our ability to ascribe fictive boundaries and
| definitions to things. Rules, authorities, myths, money,
| culture, countries, companies. What are any of them? They're
| all made up. We could just stop believing in all of them
| tomorrow.
| chrisco255 wrote:
| For #2, I would alter this to say: connections matter.
|
| We are more likely to pursue careers or interests if we know
| someone (and are friends with them or related to them) that is
| interested in the same thing or has had experience in the same
| thing.
| vidanay wrote:
| #3 really hits home when you realize _we have rules for killing
| each other_ (war). And we have separate legal trials to
| determine if someone broke those rules while trying to kill
| someone else. The penalty for breaking the rules about killing
| someone often is to be killed.
| quickthrower2 wrote:
| What does representation mean in this context?
| bcrosby95 wrote:
| I've noticed #2 with my 4 year old. She won't do anything
| unless there's a girl doing it. My other kids don't seem to
| care though.
| PartiallyTyped wrote:
| There are some interesting studies about girls and women
| playing chess. When blind, the two sexes perform on average
| about the same, but when they know the gender of their
| opponent, girls and women underperform.
|
| It is hypothesised that the reason behind this is because
| chess is a boys' club, so to speak, and thus there is not a
| lot of representation.
|
| Absence of representation means that it may seem that you are
| the only one doing XYZ, which in and of its own can be
| terrifying because we often feel that the odds are stacked
| against us (which is a self-fulfilling prophecy), or that we
| are held to much higher standards than others.
|
| Personally, I enjoy seeing diverse representation even if I
| am not represented. I want people to not be afraid to pursue
| their dreams and goals, I don't want implicit prejudices due
| to lack of representation either.
| nivethan wrote:
| 2. Hits home for me as I've begun to realize the same thing.
| Not seeing any person of color in an activity makes it's so I
| don't want to be the first.
| akira2501 wrote:
| > makes it's so I don't want to be the first.
|
| This makes me curious. Would you mind answering, from your
| point of view, why do you think that is? Is it a specific
| scenario or type of scenario you wish to avoid or is there a
| generalized concern that comes with it? Is that due to
| uncertainty or past experience?
| [deleted]
| yieldcrv wrote:
| Similarly this gives me pause about Ivy League MBA programs.
|
| Although a small sample size, despite their ambitions the
| BIPOC people I know haven't been able to reap any
| professional benefits from it. Whether from access to
| executive roles, getting taken seriously by venture capital
| firms, or in their attempts to join venture capital firms.
| There is a level of discretion in these team forming
| situations that is not extended to them whether it has
| anything to do with their race or not, its pretty clear the
| upwards mobility is not coming from this credential.
|
| For people with their own capital and leverage, it amplifies
| their ambition if they want. BIPOC don't really have this.
|
| The "average salary" of MBA alumnis is not what is
| interesting about getting one, for me or them.
|
| Some, or more, examples to the contrary would make it seem
| less like a total waste of time.
| crackercrews wrote:
| So even with all the BLM advocacy, there is no pipeline for
| Black people with MBAs from Ivy League schools? That
| doesn't fit with what I've seen in other industries.
| Companies fell all over themselves to hire Black people. Is
| this not happening in MBA-land?
| idiotsecant wrote:
| I am not an ivy league MBA person but my understanding of
| these sorts of things is that it's not the credential
| itself that's useful, but the connections you make in the
| process.
| yieldcrv wrote:
| yes, all participants were aware of this, and yet the
| connections resulted in no improved professional access
| or ability to exchange time for food and shelter.
| threadweaver34 wrote:
| > the BIPOC people I know haven't been able to reap any
| professional benefits from it
|
| Probably because there's almost always an Asian who's more
| qualified or a white with better connections. The problem
| is the key insight you get from a BIPOC is BIPOC tend to
| not have much money (set aside equity and vicious cycles
| for another day), so unless they're your market, you're not
| interested in marketing to people who can't afford your
| products.
| ShredKazoo wrote:
| As a white guy, I'd certainly encourage you not to worry
| about this -- if we're talking about an upper middle class,
| professional-ish activity, you can be fairly sure that all
| those white people feel self-conscious about their group
| being so white and would welcome you to join them.
|
| Anyway, I'd be interested to hear more about the psychology
| of this.
|
| I remember when I was growing up in the 90s and 00s in
| California, people talked about race _way_ less than they do
| today. When ethnic representation became a common topic of
| conversation, I had a hard time believing it at first,
| because it seemed so self-evidently obvious to me that race
| wasn 't a particularly important characteristic of a person.
| I actually had the experience of thinking back to my time in
| jr high/high school and thinking "wow, that friend of mine
| had dark skin, and they weren't from India... I guess they
| were Black, huh".
|
| I'm not trying to claim that I didn't have subconscious
| biases related to race as a kid. I'm sure I did. But I do
| suspect they have become a lot more severe as a result of
| people talking about race so much -- it has become a much
| more salient characteristic. (I'm also more aware of trying
| to mitigate my biases and avoid microaggressions and so on,
| of course.)
|
| So yeah, I'm curious to compare notes with other 90s kids in
| this regard. I'm white, but if I was Black, I _imagine_ that
| I 'd be way more self-conscious about it now than I was when
| I was growing up. (Like, if I'm the only white person in a
| group, I feel self-conscious about it now in a way that I
| didn't feel when I was a kid.)
| human_person wrote:
| I'm not sure > As a white guy, I'd certainly encourage you
| not to worry about this -- if we're talking about an upper
| middle class, professional-ish activity, you can be fairly
| sure that all those white people feel self-conscious about
| their group being so white and would welcome you to join
| them.
|
| Is as helpful as you may have intended. The comment was
| about not wanting to be the first, even if the group is
| welcoming, the commentator will still be the first/only
| person of color in the group and there is a discomfort
| inherent to that even if everyone is trying to be
| welcoming.
|
| Also re "colorblind" policies of the 90a versus the
| explicitness of today, I think it's similar to the current
| reckoning in journalism. We all have biases and pretending
| we don't/acting like we are capable of pure objectivity
| simply hides them and makes them more difficult to combat.
| On the other hand explicitly acknowledging them allows you
| to consider how they might be influencing your decisions.
| ShredKazoo wrote:
| For the colorblindness part, I think my core objection to
| the cultural changes which have occurred since I was a
| kid is not to increased awareness of biases per se, but
| rather this phenomenon: https://ncase.itch.io/wbwwb
|
| My feeling is that the best way to reduce subconscious
| bias is to have good race relations. And the best way to
| have good race relations is to have more positive
| interactions than negative interactions.
|
| A thought experiment: Imagine a non-Mexican person says
| "I love celebrating Cinco de Mayo. It's an excellent
| excuse to drink tequila!"
|
| As a culture, we can decide whether that's a positive
| interaction or a negative interaction.
|
| We can make it a positive interaction by laughing and
| clinking glasses.
|
| We can make it a negative interaction by calling the
| person out for cultural appropriation or trivializing an
| important Mexican holiday.
|
| My intuition is that making it a negative interaction is
| a big mistake, because it worsens subconscious racial
| biases and generally makes the world a less pleasant
| place. I recommend playing this game
| https://ncase.itch.io/wbwwb to better understand my
| intuition here. (Based on what I've read about
| Israel/Palestine, the game is an excellent description of
| why things have been getting so bad there lately.)
| ShredKazoo wrote:
| I certainly didn't mean to invalidate their discomfort --
| as I mentioned at the end, I feel the same way sometimes.
| I apologize if people found it invalidating.
|
| I actually wrote the initial draft of my comment with
| welcomingness as sort of a background assumption in my
| mind, and then I thought "wait a minute, even if I'm
| assuming that people would be welcoming, the person
| reading my comment might not. and given how hostile
| online discussions can get, it seems safer to err on the
| side of emphasizing welcomingness." That still seems
| roughly correct to me -- I think some topics have so much
| hostility associated with them that whatever you're going
| to say about the topic, it probably makes sense to also
| add in a bunch of welcomingness too, just so the
| discussion goes well.
| alphydan wrote:
| The better question to ask yourself (you the white guy), is
| would you join a group [insert som hobby like hiking]
| composed 100% of Cholitas. If yes, are you sure? if not,
| why not?
|
| *Not singling out Cholitas, but it's a group that may feel
| "other" to you.
| faddypaddy34 wrote:
| The better question is would that group let a lone white
| guy join?
| ShredKazoo wrote:
| As I stated, I've had the experience of feeling self-
| conscious in a group where I was the only white person
| (or one of just a few). That never happened when I was a
| kid, but it has happened a few times as an adult.
|
| With regard to the Cholitas thought experiment, I think
| my major source of discomfort is that at least one of
| them would look at me and think to herself "he's a
| patriarchical colonizer" and feel hostility from that.
| I'd feel more comfortable if I had a friend in the group
| who could vouch for me. Otherwise I'd worry the Cholitas
| didn't want me to be there.
|
| I suppose that works in reverse as well -- an ethnic
| person might look at a group of white people and worry
| that one of them was present at Jan 6 or what have you.
|
| What I miss from my childhood was the feeling that we're
| all in this together as human beings and race just isn't
| important. In the time & place I grew up, if someone was
| to start denigrating others on the basis of race,
| everyone would consider them to be an unimportant wacko.
| In that cultural context I wouldn't feel as much
| apprehension joining a group of Cholitas.
| crackercrews wrote:
| If I lived in a majority-Cholita area, I would not give
| it a second thought. If I lived in an area with not many
| Cholitas, I would wonder if there was a reason the group
| had only Cholitas.
| jasonwatkinspdx wrote:
| Growing up this was a big realization for me the other way. I
| was raised by evangelicals in Kansas, including going to a
| mennonite school for most of my education. As a teenager I
| realized how at my school, at my church, at basically
| everything in my family's shared life, there was not a single
| person with brown skin. Not even one. And worse, no one had
| real awareness of this, and would not understand how it could
| be any sort of problem if you brought it up. To them it was
| just the natural order of the universe that their world was
| purely white people.
|
| There's plenty of evangelicals of every race, but overall the
| communities are very segregated. It was clear no matter their
| professed faith, in practice the community I grew up in was
| hostile to PoC.
| rajin444 wrote:
| > 2. Representation matters.
|
| Strange, I had the opposite encounter. I realized the only
| thing keeping me from doing things was myself. There are
| definitely real barriers (hiring quotas, affirmative action,
| etc.) but without artificial constraints the only thing
| stopping you is you. You might feel a little uncomfortable but
| that's something easily overcome - and almost like a superpower
| when you realize you can overcome an external locus of control.
| human_person wrote:
| Since you are referring to affirmative action and hiring
| quotas as "real barriers" I would guess that you haven't
| really been in a situation where you the first/only person of
| your gender or race (etc) to do something. In that case
| (since you haven't lacked representation) I'm not sure how
| well you can speak to its importance. But please correct me
| if im wrong.
| fortituded0002 wrote:
| This is actually how it played out for me once I recognized
| it. I'm of the mindset now that I can jump in and do things.
| And I think you hit on one of the most important lessons that
| came out of it for me - the only thing stopping you is you.
|
| With that said, some form of representation helped me greatly
| with it. It doesn't need to be an exact match, but for me it
| needed to be enough to make me break my assumptions and see
| whatever weird walls I had put up in my thinking.
| [deleted]
| yieldcrv wrote:
| most of us here have our own drive, but I've come to
| appreciate that _other people_ are inspired by seemingly
| superficial things
|
| It clicked for me when I let my publicist go wild and she got
| me on listicles of BIPOC founders, before, we just had lots
| of quotes and interviews. Only people already interested in
| the project on its own merits were following along. After,
| there were lots of people that are interested in the
| representation in that kind of niche who otherwise just
| wouldn't know how to find that representation. Or just
| wouldn't be able to tell by founder names alone.
|
| and of course we got the amplified engagement from people
| arguing about "why does race matter" in the LinkedIn
| comments. so shoutout to the useful idiots, publicists expect
| that to exist and calculate it.
| rajin444 wrote:
| > inspired by seemingly superficial things
|
| This seems similar to adding an addictive drug to food. It
| will certainly appeal to a lot of people, but does it add
| value? Getting more consumers of your product should not be
| the end goal if we want a healthy, high trust society.
| Developing a good product should be.
|
| > Only people already interested in the project on its own
| merits were following along
|
| Isn't this what we want as a society?
| yieldcrv wrote:
| save these goals for your non-profit
|
| the rest of us want revenue. there is no build it and
| they will come, its appealing to people's sentiments, and
| the people have to know its there at all.
| imwillofficial wrote:
| Ah, questioning the morality of exploiting human nature
| is for non profits. Got it.
|
| There is a right way and a wrong way to achieve success.
|
| Profit is not the only thing that matters in life.
| PartiallyTyped wrote:
| That reads like a very condescending and cynical response.
|
| People enjoy representation, imho, because it helps them
| see that they are not alone, that the deck isn't stacked
| against them, and so on. It also helps in removing
| prejudice against certain groups of people.
| enos_feedler wrote:
| I would tread carefully when saying any kind of discomfort is
| "easily overcome". We are human beings after all and it's a
| pretty generalized statement.
|
| Being a white male but simply being unique in coming from a
| poor community in a poor city was enough for me to inflict a
| lot of unnecessary pain on myself through undergrad by seeing
| myself as different from the majority of elites in my
| program.
| crackercrews wrote:
| Interesting interplay between 2 and 3. Why does representation
| matter so much if these are just human-created constructs?
| Genuinely interested to know how the same person had both of
| these epiphanies.
| fortituded0002 wrote:
| Ha, interesting observation. They didn't happen at the same
| time. #2 followed by #3 much later.
| slotrans wrote:
| For me the big one was relational modeling & normalization. I
| took a database class in college and I thought normalization was
| idiotic. It seemed obviously foolish and wasteful and I couldn't
| imagine why anyone would do this to themselves by choice. Then ~2
| years later I got a job working with data, at a company with
| quite a big database that was designed largely by experts. Within
| a few months of starting to work with real data I had
| internalized the Why of normalization and become a believer.
| Ironically I've been doing database work ever since.
|
| Lately I've worked for a number of companies where no one -- like
| seriously, absolutely zero developers on the team -- understand
| normalization. They may perform a shadow of it, because someone
| somewhere told them to, or some article said this is how you
| model data that looks like X, but they don't _get_ it.
| Predictably, their data models are absolute garbage. Teaching
| them is an uphill battle because they don 't care, they're not
| curious, and their web frameworks ( _cough_ Rails _cough_ ) have
| taught them to distance themselves from the database and treat it
| as dumb.
|
| The other one was Rich Hickey's "Simple Made Easy", which I first
| watched in 2013. I enjoyed it even then but I didn't really
| understand what he was getting it. After working with, and
| building, some systems done in a functional style, I feel like I
| figured most of the ideas. That would have been some time in 2017
| so, definitely took a while to soak in.
| dgudkov wrote:
| Data visualization. I had many years of experience with data
| analytics, but only when I read "Now you see it" by Stephen Few I
| started understanding how data visualization is linked to the way
| the human eye and brain work.
| Simon_O_Rourke wrote:
| The concept of decorators in Java and Python - I know what
| they're supposed to do, but each time I find myself grinding my
| teeth when using them, thinking there's a better way of doing the
| same things more simply.
| kozak wrote:
| Entropy. Both in information and in thermodynamics, and how
| brilliantly they are connected. The audiobook "The Big Picture"
| by Sean Carroll has helped a lot.
| spritefs wrote:
| 1. Being able to derive bottom up dynamic programming leetcode
| solutions. The only way I really "figured out" how to do this was
| by reading the dp chapter out of the Cormen algorithms book. It's
| crazy how illuminating (and rare) clear explanations are
|
| 2. The chain rule. I knew the actual rule from a calc class, but
| the intuition behind it didn't make sense to me until I read a
| couple pdfs on backpropagation
|
| 3. Money brings out the worst in people
| ChrisMarshallNY wrote:
| In my case, almost everything has been like that.
|
| 1) I learn rote.
|
| 1.1) Almost no improvement.
|
| 2) I "get it."
|
| 2.1) My development in that area suddenly _explodes_.
|
| This has happened with almost every software concept, from
| calculus, to Structured Programming ("Whatever will I do without
| my precious GOTOs?"), to Object-Oriented Programming, to Design
| Patterns, to Protocols, etc.
|
| It usually only takes weeks or months, but I suspect some have
| taken years.
| progJustMath wrote:
| [dead]
| itsgrimetime wrote:
| programming in general, i tried probably half a dozen different
| times throughout my early teens to understand how to write
| programs in pascal, C, python, java, and it wasn't until I was 18
| when I found Zed Shaw's "Learn Python the Hard Way" that it
| clicked.
| itsmemattchung wrote:
| The power of an outline when writing.
|
| Over the past few years, I've been teaching myself how to write
| better. I'm not talking about elementary syntax or grammar. I'm
| not talking about writing the traditional, American English five
| paragraph essay. I'm talking about writing longer pieces of
| prose, articles or blog posts or short chapters with word counts
| ranging anywhere between 1500-3000 words. On this journey of
| improving the craft, I realized that one of my biggest struggles
| was writing cohesively. Although I've been able to get lots of
| words on (digital) paper, eventually I'd get lost in my own web
| of thoughts, the article itself totally incoherent, no structure,
| no organization.
|
| Constructing outlines and _reverse_ outlines[0] has helped me
| tremendously. It 's not easy ... but the concept itself is
| finally -- years later -- starting to click.
|
| [0] - https://explorationsofstyle.com/2011/02/09/reverse-
| outlines/
| binarymax wrote:
| I also love and need outlines. It's carried forward in not just
| writing, but making great presentations, plans, and decision
| making.
|
| Also, obligatory RiffTrax on outlines:
| https://youtu.be/yfcyVtD8-Dk
| bitwize wrote:
| Using org-mode's powerful outlining functionality has done
| wonders for my writing. I can ramble on and on and on, then use
| headings and subheadings to create conceptual "bins" and move
| chunks of my prose into the bins depending on topic, then
| smooth my words over with more transitional language so the
| thoughts flow more naturally.
| cookie_monsta wrote:
| I love a good outline and can't really imagine writing anything
| above 1000 words without one. Getting the outline into shape
| really feels like breaking the back of any piece - after that
| it's just filling in the gaps.
|
| Something I realised much too late was how delaying the move to
| the keyboard was a useful strategy. Now I mostly start with pen
| and paper, sometimes with a mind map if I really need to
| organise my thoughts, and only hit the PC once I have a pretty
| firm idea of what I'm going to say. I've even done first drafts
| in longhand, which feels like double handling at first, but
| there's something about that added filter of transposing from
| paper to computer that helps you reassess objectively what it
| is that you're writing.
| catears wrote:
| This summer I read "On Writing Well" by William Zissner which
| was an eye opener for me. I'm far from an expert in writing
| clear texts, but I am definitely noticing more text which are
| just... big balls of blurb that don't actually say anything.
| All because of that book.
|
| It sounds dumb, but this year it clicked for me how big of a
| difference a poorly written text compares to a well written
| text.
|
| Hope your training pays off, itsmemattchung!
| grantc wrote:
| This is the first book I recommend to anyone who wants to
| improve their writing. With Minto's Pyramid Principle as a
| follow-on.
|
| My top 3: 1/ Edit ruthlessly. Every single word is reduced to
| its simplest form and pulls its weight--it has a damn good
| reason for being there. 2/ Aspire to write at a third-grade
| reading level. Readers prefer simple writing even when
| reading deeply technical content. 3/ Start your most
| important conclusions up front, not at the end. You're not
| writing The Sixth Sense. Do your reader a favor and tell them
| the big reveal first. You can then follow through and
| persuade the reader why your conclusions are right.
| urthor wrote:
| Bottom Line Up Front and "Anything worth reading is 10% of
| the first draft," are the two hardest procedural skills in
| writing.
|
| It's just so much experience to avoid those mistakes.
| luuuzeta wrote:
| Zinsser's "On Writing Well" is one of my favorite books, I
| like how clear and concise its prose is.
|
| I got Joseph M. William's "Style: Toward Clarity and Grace"
| recommended [1] so you might be interested in it. I read the
| introduction (I'm planning to read it this year) and with the
| few examples the author presents it sells the idea that prose
| doesn't need to be utterly complex to communicate ideas and
| concepts succinctly and clearly.
|
| [1]: https://news.ycombinator.com/item?id=33601492
| buzzert wrote:
| For me, it was the difference between "is" and "ought".
|
| It sounds obvious when you first think about it, but I spent a
| vast majority of my 20's with a view of the world filled with
| "oughts" instead of "is's", especially when it comes to things I
| can't control. I.e., people "ought" to behave a certain way,
| versus the way people actually behave. The way
| companies/governments "ought" to operate, versus the way they
| actually do.
|
| Thinking in terms of "oughts" can really cloud your judgement in
| ways that you might not be totally aware of. I guess this is kind
| of like the "realpolitik" philosophy, but coming to this
| realization in my early 30's actually made me a lot happier and
| less confused about why the world is the way it is.
| satvikpendem wrote:
| Are you familiar with the is-ought problem? Somewhat related.
|
| https://en.wikipedia.org/wiki/Is%E2%80%93ought_problem
| whalesalad wrote:
| We are all just children. As kids we always want to be adults but
| then we become adults and ultimately everyone around us is just a
| child who's been on the earth longer.
| mmcconnell1618 wrote:
| Compound Interest. The idea and the numbers made sense but it is
| only with many more decades of life that I understand how much
| impact time has on compounding. If I had understood this when I
| was younger, I would have made different choices in regards to
| saving more. Small sacrifices when you're younger and can easily
| tolerate them, have massive dividends later in life.
| ryanschneider wrote:
| Calculus, even the basics like derivatives, 2nd derivatives and
| integration didn't really click with me until I did some
| scientific computing/signal processing with SciPy and Pandas a
| couple years ago. Graphing the discrete versions on time series
| data, e.g. graphing the difference between consecutive values and
| seeing the derivative pop out, or a rolling sum for integration,
| etc finally made it all click.
| wiseowise wrote:
| Programming languages don't matter.
| lqdc13 wrote:
| Forward-Backward algorithm before there were all sorts of
| resources and explanations on how it works online.
|
| The wikipedia page for it explains it well.
| parasti wrote:
| One of the biggest realizations recently for me was realizing
| that a nearly all of software development is basically about
| turning a slow, manual process into a faster, automated process.
| Modern CI/CD stems from a bunch of shell commands that somebody
| wrote and manually executed to test an app and upload it to a
| server. Modern automated software testing stems from humans
| writing small test apps and running them to confirm correct
| behavior. Many modern development practices stem from allowing
| small test apps to be written easier and faster. It's all just a
| giant manual process-to-automated process time-saving machine.
| tantalor wrote:
| This is a great way to understand complex, new-fangled
| technologies. Ask "what manual process does this speed up"?
| jstummbillig wrote:
| To add on to this, when you think in term of software
| development, that's already pretty meta because you skipped
| level 1: Formalizing any type of process. Something that is the
| entry level requirement to get, well, anything done via
| programming, is actually only done sporadicly in a lot of not-
| software fields.
| __s wrote:
| In fact a well designed system I work on (database service) is
| built to give people sufficient monitoring & control that
| operators handle anything out of the ordinary until they get
| annoyed enough to automate it
| urthor wrote:
| Save humans time with a workflow.
|
| Save humans time.
|
| Save humans time.
| tails4e wrote:
| The fourier transform. Encountered it first in my undergrad
| engineering degree, it was presented as dry mathematics, with no
| real explanation, just threw complex exponentials at us, and
| pages of derivations. Years later I actually use it in my job,
| and through that and other material can see its beauty, and how
| its actually not that complicated. Some great resources like this
| helped a lot:
|
| [0] https://betterexplained.com/articles/colorized-math-
| equation...
| rramadass wrote:
| In case you didn't already know; _Who Is Fourier?: A
| Mathematical Adventure_ is an excellent illustrated book on
| this.
| sjaak wrote:
| This is what made it click for me, can recommend it:
|
| 3Blue1Brown -- But what is the Fourier Transform? A visual
| introduction.
|
| https://www.youtube.com/watch?v=spUNpyF58BY
| kippinitreal wrote:
| That video did the same for me. I also like the reducible
| video for Fast Fourier Transforms as well as the Veratasium
| piece that shares some fun history.
|
| Reducible - FFTs the most ingenious algorithm ever
| https://youtu.be/h7apO7q16V0 Veritasium - The Most Important
| Algorithm of All Time https://youtu.be/nmgFG7PUHfo
| deepersprout wrote:
| Haskel monads.
| jvans wrote:
| There is a common saying that if you can't explain something to
| someone else then you don't really understand it yourself.
| Monads made me realize that some things need to be experienced
| in order to be understood.
| sampo wrote:
| Eigenvectors
| iddan wrote:
| Someone once told me he derives his self-confidence from the
| dialogue with himself. It took me a few years to understand it:
|
| 1. A clear dialogue with oneself is establishing certainty about
| the inner self
|
| 2. Certainty with the inner self enables one to see the outside
| in a clear way
|
| 3. That clarity contributes to confidence in one's actions.
| skatanski wrote:
| I think I've read about git multiple times before I started using
| it. And even then at first it was with a dash of scepticism. I
| can't put my finger on that moment, the moment of clarity but it
| had to be quite glorious. Before, I was "what else do you need we
| have svn". Sounds horrible now that I think about it.
| rubberband wrote:
| Pfft. I believe that anyone who read about git, and responded
| "yeah, duh, it's so obvious" is a dirty, dirty liar.
|
| An explanation of "interactive rebasing" to me might as well
| been an explanation of quantum entanglement to a learning-
| disabled ant.
|
| Sometimes it still trips me up. I have an embarrassingly large
| number of copies of source folders, despite git's safety net of
| "don't worry, you can always restore it; pinky swear..."
| quickthrower2 wrote:
| I would never rebase at the command line and avoid rebasing
| generally to the chagrin of team mates. A merge retains the
| information to reconstruct the rebase anyway so might as well
| use the simpler option. Unless there are a lot of commits
| such that in aggregate they conflict but individually they
| apply smoothly.
| grogenaut wrote:
| It took me 4 tries over 10 years to get antlr to work/grok.
| colinwilyb wrote:
| Formal logic.
| ojr wrote:
| Objective-C message passing/variable declaration's the syntax is
| so different from C, C++, Java, Javascript, Ruby, Python and
| other popular OOP languages
| furyofantares wrote:
| Gender as a social construct, separate from biological sex.
| ngalaiko wrote:
| for me it was functional programming. and not just fp as is, but
| it's relation to another popular concept - oop.
|
| i was properly introduced only to oop, and grasped a little of fp
| here and there, especially learning go and javascript.
|
| what i consider a 'click' for me is when i realised that all of
| these paradigms are interchangeable. like, an abstract method is
| just a function, or a function signature is the same as in
| interface with a single method.
|
| after that i write code however it feels more appropriate for the
| situation i am in and don't think too much about fancy words and
| patterns. it really feels like programming languages are becoming
| 'native' for me.
| satvikpendem wrote:
| You should learn Haskell, that's what I'm doing now, in order
| to learn functional programming from the ground up. Languages
| like JS which have FP concepts aren't really functional
| programming fully.
| khaledh wrote:
| YAGNI and KISS.
|
| When I was a junior developer I used to overthink and overdesign
| solutions, most of which was never needed. It took many years and
| a lot of battle scars to realize that less abstraction is more.
| Today I see a lot of juniors do the same mistake and I ask them
| to revise their designs to keep it simple.
| [deleted]
| coffeebeqn wrote:
| I use the rule of threes to kill off any premature
| abstractions. ie. Don't think you need to make this generic if
| you have one or two different variants of it. Most often it's
| one- so it's very easy to see that you're just solving
| imaginary problems at this point.
|
| Each abstraction has a mental cost for reading and
| understanding the code so I try to be sparing. Too many code
| bases in my youth were a nightmare to navigate because I could
| never find any actual concrete code.
| fullstackchris wrote:
| Also don't forget that code (including the complexity you
| want to add to it) will probably have only something like an
| aggragate ~1/3 chance of still being used in a production
| scenario 5 years or so away anyway (for any number of reason,
| product change, feature removal, company bought / sold, the
| list goes on and on...) of course these numbers are anedotal
| but the point is it can be detrimental to think your code
| will run as is for the next million years, especially after
| the first draft
| adamnemecek wrote:
| The fact that essentially all concepts in math, programming,
| physics etc. are just applications of fixed points which is
| predicated on the idea of nilpotence. Fixed points go by many
| names like invariance, spectra, diagonalization, embedding,
| braids etc.
|
| By fixed point I mean something like the "Lawvere's fixed point
| theorem".
| https://ncatlab.org/nlab/show/Lawvere%27s+fixed+point+theore...
|
| I have a braindump on this https://github.com/adamnemecek/adjoint
|
| I also have a discord https://discord.gg/mr9TAhpyBW
| lamontcg wrote:
| Big bang didn't happen in a single point in our space-time like a
| firecracker, it happened everywhere and was just a uniformly much
| hotter and denser universe that didn't really explode into
| anything, but space-time just expanded to make the universe less
| dense.
| namrog84 wrote:
| Don't some people prefer to say the slow expansion over using
| the term big bang? Although it hasn't taken off as a term. Or
| something like that?
| antiquark wrote:
| The idea that atheism is a form of religion.
| apienx wrote:
| Or just a personal relationship with reality. :P
| aj7 wrote:
| That the integral I-V relations for an inductor and capacitor are
| the fundamental forms, not the differential relations.
| tevon wrote:
| Anyone who is excels is out of their depth.
|
| By definition if you continue to progress (in career or life),
| you will be doing something you have never done before. This
| means everyone that we look up to who appears to be on a upward
| trajectory is making it up as they go.
| revskill wrote:
| Everything is a monoid to be useful.
|
| Now i understand more about why 1+1=2.
| mejutoco wrote:
| Complex numbers, as a convenient representation for certain
| operations, in the same way as we use negative numbers to
| represent debts.
| klysm wrote:
| The certain operation almost always being rotation in my
| experience
| bob1029 wrote:
| I'd have to say... Linear Algebra & SQL.
|
| SQL is something that is a permanent journey for me. It is a
| domain-specific language, so the nature of its use depends almost
| entirely on how the domain was modeled in the first place. Much
| of my interest has been drawn towards the modeling aspects and
| how we can arrive at schemas that business experts can tolerate.
|
| Linear algebra properly clicked for me when I started getting
| into writing my own 3d rendering software. Systems of linear
| equations are absolutely everywhere. I didn't really tie together
| their use in control theory, DSP and graphics until I was forced
| to learn them "for real" to achieve my project goals.
| pfdietz wrote:
| Something in linear algebra clicked for me when I realized the
| infinite dimensional case is different from the finite
| dimensional case.
| bob1029 wrote:
| What are some applications / examples for the infinite-
| dimensional case?
| pfdietz wrote:
| The continuous Fourier transform, for example, or more
| generally linear operators in functional analysis.
| sampo wrote:
| Quantum mechanics
| andyjohnson0 wrote:
| The attachment theory of adult relationships [1].
|
| Sometimes you just have to go on the journey to understand what
| stopped you getting to your intended destination.
|
| [1] https://en.m.wikipedia.org/wiki/Attachment_in_adults
| erdos4d wrote:
| Frechet differentiation.
| 2devnull wrote:
| The importance of play.
| iancmceachern wrote:
| The simple beauty of the calculus integral.
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