[HN Gopher] Reality has a surprising amount of detail (2017)
___________________________________________________________________
Reality has a surprising amount of detail (2017)
Author : tosh
Score : 366 points
Date : 2023-11-24 20:25 UTC (1 days ago)
(HTM) web link (johnsalvatier.org)
(TXT) w3m dump (johnsalvatier.org)
| k__ wrote:
| Let's build an API.
|
| I need a CI/CD pipeline to deploy it.
|
| I should use a static code analysis tool.
|
| I need an observability tool!
|
| Let's to security code reviews.
|
| Do I have a SBOM?
|
| Which MFA should I use?
|
| Should I put it inside a container or go serverless?
|
| Better generate a OpenAPI spec!
|
| Do I have enough tests?
|
| Oh, I need blue/green deployments!
|
| Should I deploy to the edge?
| pschuegr wrote:
| I'm personally convinced that a lot of arguments in modern life
| boil down to not going to a sufficient level of detail. Mostly I
| find that both parties in an disagreement have valid points and
| simply haven't defined their terms precisely enough or been clear
| that they are talking about a p95 vs a p5 situation.
| emmelaich wrote:
| I agree, most of the time you need to refine and quantify the
| question.
|
| People are resistant to that though. If I'm being generous I
| think they think it's just saving time, because they 'know' the
| right answer. But the melancholy cynic in me wonders if it is
| just ego.
| pschuegr wrote:
| I don't think it's cynicism to realize that people are
| imperfect creatures subject to the whims of insecurity and
| ego, not being well slept, yadda yada. To me that's just
| realism.
| tsiike wrote:
| it can be hard for me to admit that my entrenched beliefs may
| be flawed but enhanced with an updated worldview...now me
| thinks this is my ego...actually i am now sure of it...a
| detail i had not previously flushed out...
| bwestergard wrote:
| This basic idea was the foundation of the logical atomist
| philosophy of Bertrand Russell and the early Wittgenstein.
| Slow_Hand wrote:
| Agreed. A lot of the past conflict in my life boils down to
| this as well.
|
| Conversely, I'm now in the habit of asking big "obvious" or
| "dumb" questions; questions that will highlight assumptions
| being made by each party. I'll often go slow at first to
| establish that these large unspoken thoughts are aligned and
| then work my way down to lower levels of detail until we hit an
| actual disagreement, rather than a mere misunderstanding.
|
| It drives me crazy to spend 30 minutes arguing with someone
| only to find that "Wait, you're talking about THAT? I thought
| we were talking about THIS."
|
| It's too common for people to find themselves arguing in the
| direction of the same general concept, but differences in their
| understanding/interpretation will diverge more and more the
| farther you get into the discussion. It's so helpful to lay out
| terms at the start when possible.
| scubbo wrote:
| Agreed - and this is why I find it _so_ frustrating when I try
| to take a step back (or down, or whichever direction seems most
| intuitive to you) and actually define terms, only to get met
| with a "you're just nitpicking about terminology, I'm trying to
| communicate ideas!"
|
| If we aren't using the same terminology, we can't possibly
| communicate ideas.
| tuatoru wrote:
| Absolutely. I summarise it as "abstraction is the curse of the
| age".
|
| My wife works in governance, and when a proposed new policy is
| being discussed, she is always the one to say "so, how would
| the policy work in this situation, with these people involved?
| [Outlines a situation.] Tell me the steps."
|
| And, of course, the elegant, abstract policy is shown to be
| unworkable or lead to manifestly unfair or absurd outcomes.
|
| I admire my wife's patience greatly.
| TeMPOraL wrote:
| I usually phrase it as arguing parties discussing a high-
| dimensional idea by projecting it down to a much lower
| dimensional space, and if they can't seem to agree, it means
| they're projecting to widely different bases - considering
| different aspects.
|
| Visual analogy: take a cylinder floating in the middle of the
| room, and a single light source you move around. As you move
| the light around, it'll cast shadows of very different shapes.
| This is merely projecting a 3D object to 2D, but if all anyone
| in the argument has is a single snapshot of a shadow, you could
| see how a person seeing a circle might have trouble agreeing
| with a person seeing a rectangle - and yet they're still
| talking about the same thing.
|
| (The biggest hurdle is to get people to realize their view on a
| topic is a low-dimensional projection of a high-dimensional
| thing, and not just _the thing_ - and that to do something
| productive with it, one must be willing to "walk around" a
| bit, project to different bases.)
| kristianp wrote:
| Previous threads with 100+ comments:
|
| https://news.ycombinator.com/item?id=29429385
|
| https://news.ycombinator.com/item?id=22020495
|
| https://news.ycombinator.com/item?id=16184255
| dang wrote:
| Thanks! Macroexpanded:
|
| _Reality has a surprising amount of detail (2017)_ -
| https://news.ycombinator.com/item?id=38304840 - Nov 2023 (1
| comment)
|
| _Reality has a surprising amount of detail_ -
| https://news.ycombinator.com/item?id=36309597 - June 2023 (1
| comment)
|
| _Reality has a surprising amount of detail (2017)_ -
| https://news.ycombinator.com/item?id=29429385 - Dec 2021 (118
| comments)
|
| _Reality has a surprising amount of detail (2017)_ -
| https://news.ycombinator.com/item?id=28006256 - July 2021 (1
| comment)
|
| _Reality has a surprising amount of detail (2017)_ -
| https://news.ycombinator.com/item?id=22020495 - Jan 2020 (115
| comments)
|
| _Reality has a surprising amount of detail (2017)_ -
| https://news.ycombinator.com/item?id=16184255 - Jan 2018 (294
| comments)
| kristianp wrote:
| This was a beautiful read until I got to the part about
| disagreements. I think it may distract from the main message
| about the complexity of tasks and the value of experience.
| huijzer wrote:
| Also related to the ending, I've come to realise more and more
| that most people reason out of belief first and arguments second
| on a lot of things (maybe most things?) Climate change deniers
| are an obvious example. But also more nuanced views such as "the
| software I make makes the world a better place" (I belief this
| myself), "me being a healthcare worker is a great thing for
| humanity", or "I need to game at least once a week to relax." And
| it makes sense. Many things are extremely complex and so picking
| one side and going for that will make sense in many cases. It's
| often necessary to be able to make decisions. However, the risk
| is getting too stuck in certain ideas. It's easier to accept a
| long held belief and reject opposing information than to re-
| evaluate.
| TheOtherHobbes wrote:
| Professional deniers are propagandists, not good-faith
| debaters. Lack of nuance is one problem, but there's a far
| bigger problem with groups of people knowingly trying to poison
| and undermine anything that resembles reality-based consensus.
| switchbak wrote:
| Absolutely - PR firms, lobbyists, astroturfers, troll farms -
| I'm in full agreement, and there's a lot of them around.
|
| Also a problem are those who label the undecided or free
| thinking among us as not being good faith actors. And
| unfortunately it's a tough position to be in, as you get
| attacked from all sides for not choosing a side.
| mistermann wrote:
| "reality-based" and "consensus" is an interesting combo, in
| general but particularly if one considers the history of
| consensus of "reality".
| Pearse wrote:
| For some reason this really speaks to me.
|
| I think it's because we create a story about every part of us
| and our life. Every thing we do (sometimes we even do it after
| the fact).
|
| I feel like those beliefs are what's keeping us grounded in the
| sense of understanding the world, of being in control. so it
| makes sense that we would start with them even if we are not
| aware of it.
|
| And it makes sense that it's hard to let them go because
| without them you get a sense that you are just floating away
| and don't have any to "hang" your assumptions on.
|
| You can reason a lot but there comes a point when things get
| bigger than you and you have to trust some other authority or
| just trust your gut.
|
| There's not many people that could comfortably reason from
| first principles and be satisfied with where they end up. (I
| don't think I could do that)
| jldugger wrote:
| > belief first and arguments second on a lot of things
|
| "support rather than illumination"
| wyager wrote:
| > I've come to realise more and more that most people reason
| out of belief first and arguments second on a lot of things
| (maybe most things?) Climate change deniers are an obvious
| example
|
| Do you think most climate change believers reasoned themselves
| into that position? I think for >95% of people, belief in
| climate change is a purely social phenomenon. The overwhelming
| majority of people don't understand enough about physical
| phenomena like blackbody radiation to have any intelligent
| opinion about climate change one way or the other.
| wingineer wrote:
| I do not think that. This similarly applies to both sides of
| some other contentious scientific/medical topics which can
| easily get someone labeled an "antivaxxer" as an ad-hominem
| directed without solid reasoning. One imagines what labels
| were given to those who did not support widespread leech
| therapy at its peak...
| galaxyLogic wrote:
| The untrue explanations are often the simpler ones. They are
| easier for people to "understand" even if they are wrong. And
| people don't like to be perceived as dumb, therefore they keep
| on arguing that they are right.
|
| Example: Flat Earth. The horizon looks flat, therefore the
| Earth must be flat.
| memling wrote:
| > Also related to the ending, I've come to realise more and
| more that most people reason out of belief first and arguments
| second on a lot of things (maybe most things?)
|
| This is the thesis to the introduction to Jonathan Haidt's _The
| Righteous Mind_. Boiling it down, he argues that self-
| justification is the most fundamental human reaction. We reason
| after, not before, and our reasoning flows to align with our
| own justification.
|
| (Luther would be proud.)
| layer8 wrote:
| Lossy compression.
| zubairq wrote:
| I agree that looking at the details really helps when reasoning
| about things. But that is hard as it is always easier to look at
| things from 10,000 feet
| incompatible wrote:
| The interesting thing is that we somehow manage to cope with all
| this complexity, both as individuals, and as a society, and
| survive. When you look at all the details, and all the things
| that can go wrong, it looks like maybe it wouldn't be possible.
|
| Also at a natural (non-man made) level, the complexity of
| biochemistry and the need to get 30 trillion or so cells working
| together as a single animal, in the presence of another 30
| trillion or so single-celled organisms of random species, doesn't
| really seem like something that's going to succeed.
| ClumsyPilot wrote:
| > cope with all this complexity, both as individuals, and as a
| society, and survive.
|
| Surviving is not thriving. Like roman construction, we just
| have very big error margings and margin of safety. Things do
| not have to work perfectly to finction
| akira2501 wrote:
| > to get 30 trillion or so cells working together as a single
| animal
|
| It's no coincidence then that your brain has a circuit to
| create backwards explanations for behavior that you didn't
| initiate, it helps create the illusion that you are a single
| animal, when in practice, you mostly aren't.
| hyperthesis wrote:
| > In retrospect, I think I saw the fundamental difficulty in what
| we were doing and I don't think he appreciated it (look at the
| stairs picture and see if you can figure it out)
|
| What was it?
| two_handfuls wrote:
| You can't rest the ladder against the wall and trace where to
| cut. Because the wall will stop the ladder.
| andrewflnr wrote:
| The biggest problem I see is that the part of the board you
| need to cut off intersects the ground. If you're leaning the
| board on the ground, you need to somehow trace a line parallel
| to the ground several inches above it. Hopefully you can solve
| that by using a spare chunk of 2x6 and tracing along that.
| Similar story for the vertical joint.
|
| I don't know if that's what the author meant, though.
| CamperBob2 wrote:
| atan2() to the rescue.
|
| Interestingly, as crude as the diagram is, you can feed it to
| ChatGPT's data analysis plugin and it will not only recognize
| what's depicted, but offer to calculate the cut angles for the
| 2x12s given the rise and run. I was pretty impressed that it
| recognized the problem without any prompting other than the
| image itself.
| andrewflnr wrote:
| Trig was already mentioned. It's definitely not the answer to
| the question GP is asking.
| hyperthesis wrote:
| Adding to the previous discussions on counter-steering bicycles:
| you can see it in tyre tracks. e.g. ride through a puddle; or,
| ride from rain to under cover.
|
| Consider: how do you steer riding no-hands? Shifting your body
| weight makes the front wheel turn (because of the "rake"), but
| now your bodyweight is on the outer side of the turn! Hold it for
| a (brief!) moment, then lean the bicycle the other way and you
| have a nice turn in the opposite direction - which is what you
| wanted all along.
| rpmisms wrote:
| This is a critical skill on motorcycles, and most people learn
| it subconsciously, but real masters can throw the bike into
| turns in ways that make no sense unless you take
| countersteering into account. I'd love to be good enough
| someday to make physics seem confusing...
| hyperthesis wrote:
| Motorcycle licence tests cover counter-steering, as an
| obstacle avoidance technique.
|
| I think gyroscopic effects are also in play, and more
| pronounced on a motorcycle, with its wheels having greater
| mass and angular velocity.
| rpmisms wrote:
| Not in the US, or at least not in Tennessee. It's taught,
| but not tested on.
|
| Absolutely. They're very unique vehicles, and I find them
| to be a fun mechanical exercise.
| hyperthesis wrote:
| No matter how closely you look, there is always more to it.
| However you think things are, good or bad, you are "wrong". But
| you may have sufficient precision to make some specific technique
| operate. (The technique is predicated on an implicit theory
| simplifying how things are. Both the technique and theory are
| "wrong".)
|
| In finding correlations between two things, a tricky bit is
| finding _which_ two things (a thing can be an arbitrary
| composites of other things). When we do find a correlation, that
| becomes how we see it, and we think in terms of this particular
| simplifying theory of reality.
|
| i.e. there are two issues: (1) reality is complex. (2) we
| simplify it.
| mistermann wrote:
| > However you think things are, good or bad, you are "wrong".
|
| Does this principle apply to this sentence? ;)
| hyperthesis wrote:
| Stolen from previous discussion
| https://wikipedia.org/wiki/Coastline_paradox
|
| The gif of Great Britain looks like it freezes at the end, but
| zoom in... it's just adding in finer detail.
| hnfong wrote:
| I thought about fractals while reading the article too.
|
| And I'm starting to worry that maybe fractal-like concepts not
| only apply to geometry (as in, "how long is the coastline", or
| "what direction is the coastline at point (x,y)?"), but to
| truths in general.
|
| Just like the article describes, "rough" facts like "water
| boils at 100C" can have tonnes of nuance, and when you drill
| down into the details, you might discover that the truth is so
| much more complicated that the notion of truth and falsity is
| lost among the vast sea of complex details. (eg.
| https://en.wikipedia.org/wiki/Phase_diagram#/media/File:Phas...
| ... who'd have thought something taught in elementary school
| would be so complicated :-/ )
|
| So is it possible that most "truths" in which we have absolute
| conviction are actually just rough understandings, and if we
| dig deep enough we'd find that we're actually mostly wrong? It
| seems insane to think that way, but I have a strong intuition
| that this might actually be the case.
| genman wrote:
| I think the main message is this here: "If you're a programmer,
| you might think that the fiddliness of programming is a special
| feature of programming, but really it's that everything is
| fiddly, but you only notice the fiddliness when you're new, and
| in programming you do new things more often.".
|
| I've done programming and construction and more than often
| construction is like programming, especially when you are
| renovating.
| anonymouskimmer wrote:
| This is non-intuitive to me because programming languages
| (above the level of assembly, probably) are made by humans to
| represent human concepts, while construction is based on
| physics.
|
| While writing that sentence I realized that programming does
| have a lot to do with logic, which is a construct of reality,
| and not humanity. So I guess it does makes sense that
| programming would be fiddly.
|
| I am not a programmer.
| anamexis wrote:
| Also, construction designs, materials, and tools are made by
| humans.
| anonymouskimmer wrote:
| Programming languages can theoretically abstract things
| away to the extent a properly formulated phrase will get
| working code from an LLM. Construction designs and
| materials are still concretely limited by what physics will
| allow.
| anamexis wrote:
| Well, programming languages are limited by what logic
| will allow, and computers (and by extension programming
| languages and LLMs) are also limited by what physics will
| allow.
| anonymouskimmer wrote:
| Yes, but the compiler or LLM can theoretically handle
| that. In the construction case the humans are a large
| part of the compiler.
| anamexis wrote:
| Humans are a large part of the compiler and LLM in
| programming too.
| anonymouskimmer wrote:
| Human choices are, yeah. My comments on this thread
| ultimately derive from an intro to programming with Java
| course 10+ years ago that I got a B- in because I never
| submitted the final project worth 20% of the grade. I bit
| off way more than I could chew in the design of the
| project, but ultimately gave up because of a human design
| choice called "type erasure" that my limited programming
| skills couldn't work around.
|
| I've always kind of seen programming above the level of
| electrical engineering as working in a social system
| designed with decisions that seemed like a good idea to a
| person who isn't me. This point was driven home a year
| ago when taking an R course and reading the literature
| discussing the grammar of R.
|
| But yeah, in addition there are physical limits for
| programming as well. That's what just came as a mild
| insight for me here. I theoretically had been aware of
| it, but as an end-user / non-programmer just hadn't
| really put it together and thought about it before.
|
| Details. :)
| panxyh wrote:
| You keep using _programming languages_ instead of
| _programming_ as an analogy. Is that thought through or
| do you just throw these two concepts in the same basket?
| anonymouskimmer wrote:
| It's thought through:
| https://news.ycombinator.com/item?id=38410024
|
| But it's thought through as a person who is an amateur at
| best. I've taken literal introductory courses to
| programming in Fortran, Java, and R, have hacked together
| two or three VBscript programs, had a very slight one-day
| introduction to assembler in the Java course, and as a
| child was briefly in a summer program that had us
| "programming" a very simple robot (telling it to go
| certain lengths in certain directions). A former roommate
| said my pseudocode (when taking the Fortran course)
| looked like Pascal, and I used to watch him do some Forth
| programming.
|
| So in terms of programming philosophy I am really, really
| clueless. But in terms of programming languages what I do
| have is a basic understanding of how incredibly diverse
| the languages are. And that a huge amount of this
| diversity is based on human preferences.
|
| As an analogy to construction. Yes, there are a diverse
| number of techniques that can be used in constructions
| (yurts, hay-bail housing, etcetera). One could also draw
| an analogy to pre-fab construction as modular programming
| and libraries as kits (or whatever). But for the most
| part, outside of scale, it seems that most construction
| effectively standardized on a few "languages", if not a
| single language.
| hashworks wrote:
| It's not just logic. Storage is in practice never infinite,
| everything has a speed limit. Those are real things, not some
| human concept.
| anonymouskimmer wrote:
| I was thinking about the human-facing end. Not whatever
| constraints the compiler is under to translate the human-
| facing end to machine-operable code.
| contravariant wrote:
| Well, programming is a lot easier if you don't have to deal
| with reality.
|
| That tends to not happen so often.
| actuallyalys wrote:
| One thing your initial reasoning left out is that human
| concepts are not simple, either. Money may seem simple until
| you start to consider currencies, rounding, taxes, fees, etc.
| Text may seem simple until you consider punctuation,
| different alphabets, math symbols, emoji, and other special
| symbols, glyphs, or characters. Names may seem simple until
| you consider suffixes, names that consist of multiple words,
| middle names, cultures that place the family name first,
| nicknames, name changes, various accents and other "special"
| characters (that probably are perfectly normal to the person
| with the name), etc. As a programmer you often have to deal
| with other programmers' solutions to handle all this
| complexity, which may be flawed or simply different.
|
| I mention all this not to pick holes in your logic but
| because it sounded like you were trying to look more closely
| at your intuition.
| anonymouskimmer wrote:
| > As a programmer you often have to deal with other
| programmers' solutions to handle all this complexity
|
| That's entirely my point. Human concepts can be incredibly
| complicated, or just as bad based on ideas that are foreign
| to others. Some people like figuring out human complexity,
| but no one likes figuring out everyone's personal
| complexity.
|
| Many disciplines are still more constrained by our limited
| understanding of, and ability to manipulate, physical
| constraints. The more abstract programming languages
| become, the more personally complex they become. Like money
| and verbal languages.
| pjc50 wrote:
| I think this distinction is artificial. Programming is made
| of and constrained by physics: the electric field in the
| transistors is a real physical phenomenon. While
| constructions are made of concepts; just ask an architect
| about "negative space".
| anonymouskimmer wrote:
| And yet the humans doing the construction still have to
| measure angles in non-obvious manners regardless of the
| kind of staircase they are installing.
| taneq wrote:
| > in programming you do new things more often
|
| Only if you don't do new things often outside of programming.
| Everything certainly is fiddly and anything new you do is going
| be technical if you care about doing it well. I spent half a
| day last week learning to paint-fill engraving to make
| labeling. Conceptually it was trivial (coat with paint, wipe
| off excess, sand back when dry) but there was still plenty of
| nuance.
| ipython wrote:
| I enjoyed the stair story here quite a bit - I find that I always
| have a newfound appreciation for the "real" jobs when I find a
| fine craftsman at work.
|
| We had a curved staircase fabricated for our house and it was
| absolutely fascinating to watch the planning and execution go
| into this task. The original measurements were plugged into a cad
| drawing where we could adjust the number of treads and the
| position of the top and bottom steps based on our preference.
| Then they fabricated the entire assembly offsite and brought it
| in via crane in one piece. Even building the handrail was
| fascinating as there was a jig built in place to bend the wood to
| the curve required.
|
| The physical constraints and fractal complexity is fascinating
| for someone like me who is used to deterministic machines moving
| bits on a daily basis.
| ulizzle wrote:
| Except when it comes to driverless cars & so-called AI. That's
| easier done than said, supposedly
| nappy-doo wrote:
| Aside: Building stairs that way is a really bad idea. Don't use
| angle brackets - you cut stringers. And besides the first and
| last step, stringers are pretty straightforward to layout with a
| carpenter's square with some stair guides (two little posts that
| screw to the square). And, generally you just layout 8" rise, 12"
| deep stairs, so you really don't lay out anything at all.
|
| But, really, don't build stairs like OP suggested.
| jcims wrote:
| Somehow as easy as it is conceptually, I still find cutting 3
| stringers that line up well to be surprisingly difficult. In
| part because I've only has to do it a handful of times in my
| life.
| jacquesm wrote:
| Either you use jigs or you tie them together temporarily and
| cut the stack.
| dylan604 wrote:
| pretty amazing how the simplest of solutions seems to be so
| elusive. i've been guilty on more than one occassion of
| making something seemingly simple as difficult as wrangling
| cats.
| jacquesm wrote:
| It's just experience. Everything you've done before or
| that you've seen done by people that knew what they were
| doing is trivial, everything you haven't done before is
| difficult.
| lelanthran wrote:
| Yup. If you're doing almost anything in wood, a set of
| clamps is more useful than you'd think.
|
| I made a table. The legs are all exactly the same length,
| but don't ask me what that exact length is - I eyeballed
| the height I wanted and then clamped all the legs together
| before cutting them.
|
| Another tip for building things with legs - a 3-legged
| object is stable on any uneven surface while a 4-legged
| objects will wobble on uneven surfaces.
|
| This is because 3 points make a plane, adding a 4th point
| that is not on that plane introduces a wobble.
| jacquesm wrote:
| Easiest way to avoid that wobble: get the legs to within
| 1 mm, add felt pad to the bottom of the legs. The
| pressure of the table will compress the felt and all four
| legs now contact the ground.
| lelanthran wrote:
| > Easiest way to avoid that wobble: get the legs to
| within 1 mm, add felt pad to the bottom of the legs. The
| pressure of the table will compress the felt and all four
| legs now contact the ground.
|
| On a level floor, sure. But for something that will be on
| uneven surfaces, like outside, 3 legs are stable, even if
| the legs are all different sizes[1].
|
| [1] Three points make a plane, the plane itself may not
| be level, but because all points of contact are on the
| same plane there is no wobble. When there are more than 3
| legs, some points may not be on the same plane, producing
| a wobble.
| devnonymous wrote:
| Yep. That's the whole principle behind stablity
| mechanisms such as tripods and easels
| nappy-doo wrote:
| A sister comment to mine gives you one strategy, but you can
| also use the first stringer as a template to the rest.
| alright2565 wrote:
| You can create a template online, print it out, and use it to
| get perfect results:
|
| https://www.blocklayer.com/stairs/straighteng, click "Show
| Notching Template", then "Diagrams to PDF"
| numpad0 wrote:
| I also don't like that fixtures at top and bottom are SPOF. Why
| not add pillars to the top and ~3rd from bottom steps, then tie
| with another beam, like an H overlapping a ladder?
|
| That way, there will be far less chances that bolts
| spontaneously rip off and stairs go down, nor the lengths of
| pillars to have to be critical dimensions. The pillars can
| optionally be cut to precise lengths to be screwed through both
| steps and slopes for maximum Apple-ness, or, can be lazily cut
| to long-enough lengths, nailed through to steps from the
| "outside", and used as base for handrails as if it had been the
| plan.
|
| (dc: not an engineering advise. consult a real engineer for
| safety. Also add cross beams in width-height plane, they help
| tremendously)
| tesdinger wrote:
| The author should just have learnt how to build stairs in a
| craft school instead of wasting time on unprofessional trial
| and error.
| deely3 wrote:
| I'm not sure that author in that times was able to afford
| craft school..
| moffkalast wrote:
| Yeah, having the steps only connected by some small screw
| brackets is borderline redneck engineering, someone's gonna get
| killed when two screws come loose.
|
| What OP was really making were misused ladders.
| contravariant wrote:
| I blame this phenomenon for why people feel mathematics is not
| useful. It is, it's just that reality is more complex than high
| school mathematics can properly prepare you for. To _understand_
| the mathematical solution, should you encounter it, does however
| require some foundational knowledge so if you don 't know any
| then you can't even begin to understand it (possibly even failing
| to identify it is mathematical).
|
| I mean take something practical like a mortgage. It's fairly easy
| to calculate the annuities using a geometric series, but that
| places it beyond most people's mathematical skills. Sure you
| could use a special calculator, or if you're adventurous look up
| the formula (beware though, Wikipedia is bound to lead to errors
| by defining the monthly rate as yearly rate / 12), and then it
| probably may not like doing mathematics at all but neither do you
| really understand what's happening.
| dieselgate wrote:
| "If people do not believe that mathematics is simple, it is
| only because they do not realize how complicated life is" -
| John von Neumann [1]
|
| Saw this quote on an art blog showing SEMs of diatoms [2]
|
| [1] https://butdoesitfloat.com/Diatoms [2]
| https://en.wikipedia.org/wiki/Diatom
|
| edit link
| hyperthesis wrote:
| Yay John von Neumann, genius of geniuses, also said _Young
| man, in mathematics you don 't understand things. You just
| get used to them._
| nlitened wrote:
| Yep, 10x _that_ for real life.
| jiggawatts wrote:
| Then you can start layering on the complexity by estimating
| repayments based on the expected variability of future interest
| rates, convert to Real Dollars based on inflation and expected
| wage growth, then compare with alternative options such as
| renting + investing, etc...
| mcmoor wrote:
| It's astounding how some of math's first practical applications
| is to calculate movement of the stars. Absence of frictions and
| close bodies make physics much easier to approximate than
| anything on earth. Maybe to have students appreciate math, we
| should have them predict eclipse one again. God create
| astronomy to teach humans mathematics.
| hyperthesis wrote:
| The oldest writing is numbers... for accounting. I'm pretty
| sure Pythagoras' theorem was for property boundaries.
| contravariant wrote:
| Although the oldest mathematical work I'm aware of on
| accounting is early medieval (al khwarizmi).
| nocoiner wrote:
| I dunno. It seems to me like high school math is a pretty
| decent foundation for understanding many important aspects of
| the world (derivatives, integrals, etc.).
|
| And I think that one can clearly and substantively "get" and
| intuitively understand and intelligently work with an
| amortizing loan without needing to understand whatever level of
| math is required to comprehend why pressing (g) (12i) on an HP
| 12c is not an atomically precise representation of of the
| answer out to the 12th decimal place.
| quelltext wrote:
| > beware though, Wikipedia is bound to lead to errors by
| defining the monthly rate as yearly rate / 12
|
| Looks like all the calculators do that as well. What's the
| right way?
| alex_young wrote:
| My mortgage company seems to use the same formula.
| sophiebits wrote:
| I assume to take compounding into account, you want the 12th
| root. Instead of 12% - 1%, 1.12^(1/12) gives around 0.95%.
| jskherman wrote:
| The effective interest rate should be calculated and then
| converted to the monthly rate:
|
| $$ \left( 1 + \frac{i_a}{n_a} \right)^{n_a} = \left( 1 +
| \frac{i_b}{n_b} \right)^{n_b} = \left( 1 +
| \frac{i_{\text{annual}} }{1} \right)^{1} $$
|
| https://www.investopedia.com/terms/e/effectiveinterest.asp
| neilkk wrote:
| My mortgage company charges interest based on the number of
| days in the month divided by 365. I have replicated their
| calculation like this. I'm not sure what they do in leap
| years - there are at least 3 distinct approaches.
| contravariant wrote:
| It could be correct, it just depends. Also according to the
| comments banks do all kinds of weird things.
| beefield wrote:
| This is a bit of a rabbit hole. The right way is whatever is
| agreed, and there are many ways to agree it.
|
| https://en.m.wikipedia.org/wiki/Day_count_convention
| BiteCode_dev wrote:
| Yet you will find that mortage interests charged by the bank
| don't match your series, because they use an accrual schedule
| with a special way to measure years fractions, then calculate
| an equivalent notional for those dates, and remap that to your
| payment calendar.
|
| Turns out there is a surprinsing amount of details here as
| well. And you don't have all parameters for the calculation,
| like often in life.
| kgwgk wrote:
| > (beware though, Wikipedia is bound to lead to errors by
| defining the monthly rate as yearly rate / 12)
|
| Lead to errors relative to what? The mathematical idealisation
| or the actual practice?
|
| Are you referring to this page?
|
| https://en.wikipedia.org/wiki/Mortgage_calculator
|
| "Since the quoted yearly percentage rate is not a compounded
| rate, the monthly percentage rate is simply the yearly
| percentage rate divided by 12."
|
| Do you think that the explanation above is wrong?
|
| In practice interest payments are calculated in many "wrong"
| ways, but that's what it is:
|
| https://en.wikipedia.org/wiki/Day_count_convention
| incongruity wrote:
| _"All models are wrong, but some are useful"_
|
| https://en.m.wikipedia.org/wiki/All_models_are_wrong
| contravariant wrote:
| I was looking at: https://en.wikipedia.org/wiki/Mortgage#Prin
| cipal_and_interes...
|
| It's not necessarily wrong, but it's missing any disclaimer
| about which interest rates they're talking about so if you
| don't know what you're doing it will lead to mistakes.
| kgwgk wrote:
| Ok, so defining the monthly rate as yearly rate / 12 will
| lead to mistakes if the yearly rate is not twelve times the
| monthly rate.
|
| (Of course any other definition of monthly rate will also
| lead to mistakes when it's inconsistent with the definition
| of yearly rate.)
| Obscurity4340 wrote:
| Cant you just use 365 instead of using something less accurate
| like 12 months (months are unevenly distributed)
| jquast wrote:
| You are correct about the mortgage payments, I had a 1-2 cent
| error every few months, after a days struggle, I simply added a
| "Penny" column to add or subtract as necessary so that they
| would match!
| maxglute wrote:
| There's a reason a huge part of technical architecture drawings
| is referred to as "detailing".
| gerdesj wrote:
| "The first problem you'll encounter is that cutting your 2x12s to
| the right angle is a bit complicated because there's no obvious
| way to trace the correct angles."
|
| Rubbish or as we say here: bollocks. Chippies have been doing
| first fit for centuries.
|
| Its lovely that someone is discovering how wood and homes work.
| All power to you. Tomorrow - bricks?
| quantum_state wrote:
| Feel all depends how one looks at things. For example, the
| vacuum, supposedly there should be nothing there. However,
| uncertainty principle allows fluctuations of all kinds which are
| not physically directly observable. If one looks at things at the
| level of principle, it is simple. However, if one tries to look
| into the actual fluctuations, there is infinite and unknown
| amount of complexity.
| jmugan wrote:
| To me, it's not so much that reality has a surprising amount of
| detail, it's that our brains make us feel like whatever model we
| have is complete. Same thing, of course, but focusing on the
| brain gets us closer to the cause.
| bonyt wrote:
| I have this comic on my wall at my desk.[1] It's about how much
| work goes into every detail of the everyday things we take for
| granted. I practice law, mostly patent litigation, and often my
| job entails untangling one of these stories.
|
| [1]: https://xkcd.com/1741/
| narag wrote:
| Seeing this here again, I was wondering if it's related to
| current events. I hope it isn't too soon, sorry to bother you in
| that case.
|
| Can't you see? Let me explain.
|
| The point of the post is that when you try to translate ideas to
| the physical world, there are plenty of quirks and you quickly
| find out what's the difference between theory and practice.
| That's why many people think that the chatting performance of an
| AI isn't a good measure of its ability to conquest the world.
|
| And that's why some are so fed up with the doom prophecies, they
| seem disconnected from reality. But I believe the general opinion
| has swung too much in the other direction and maybe, just maybe,
| it's not wise to completely stop thinking about safety.
| somewhereoutth wrote:
| If this comment is the best LLMs can do then really we have
| nothing to worry about
| omneity wrote:
| This was a brilliant read for me back in the day (still is!) and
| gave me the inspiration to write a post[0] about detail
| abstraction, market forces and why you can't fit big cups in
| coffee machines.
|
| [0]: https://omarkama.li/blog/the-market-decides-your-project-
| sco...
| akoboldfrying wrote:
| >Frames are made out of the details that seem important to you.
|
| Beautiful, and explains so much.
| ashu1461 wrote:
| This reminds of Dunning Kruger Effect
| https://www.youtube.com/watch?v=4FGnb2lgPBA
|
| people often tend to over estimate their capabilities and then
| only later once they start working on a project after some time
| realise that things are not that straightforward.
| mcmoor wrote:
| > If you're trying to do impossible things, this effect should
| chill you to your bones. It means you could be intellectually
| stuck right at this very moment, with the evidence right in front
| of your face and you just can't see it.
|
| It has always chilled me to my bones. Whenever I tried to do a
| slightly non trivial things, I am afraid I miss the super obvious
| easy solution and get stuck for years before getting it. And it
| already happened several times too! Really, the only solution I
| can come up with is "experience"... and a lot of asking from
| different perspective.
| gregfjohnson wrote:
| After much initial resistance, I've become a fan of pair
| programming. When things are clicking, ideas spark back and
| forth. Frames collide and interfere, bits of partial insight are
| exchanged, and you and your partner arrive at a solution that
| would have been impossible for either of you to get to working
| individually.
|
| There is the famous psychological notion of flow. The thing is,
| this can happen among multiple people. Think of a lovely choir or
| orchestra. Or a basketball team where every team member just
| seems to be reading other team members' minds. The book (and
| presumably the upcoming movie) "The Boys in the Boat" really
| emphasizes this and crystallizes this.
|
| As the linked article mentions, the author and his father butted
| heads for three hours because they were not listening to each
| other and pairing very effectively! Really good pairing does take
| work and practice. But when it starts to work there can be
| moments when it feels like magic. It is a great way to grapple
| with the myriad of unforeseen "details" that are actually life-
| or-death critical issues to project success.
| ulizzle wrote:
| I actually think it's far better to pair program with ChatGPT
| instead of another human.
| ozfive wrote:
| Yes, because... Physics and you know, Math.
| clumsyninza wrote:
| The link doesn't seem to work.
| clumsyninza wrote:
| The link doesn't seem to work
| RagnarD wrote:
| This is an unusually rare, worthwhile piece. It's rare for
| somebody to be both very grounded, with a personal history of
| hands-on practical competence, yet simultaneously abstracting his
| experience to a high philosophic level.
| RagnarD wrote:
| A nitpick is this statement: "The massive difference in weight
| between a rocket full of fuel and an empty one means that a
| reusable rocket can't hover if it can't throttle down to a very
| small fraction of its original thrust, which in turn means it
| must plan its trajectory very precisely to achieve 0 velocity
| at exactly the moment it reaches the ground."
|
| I don't think this is how SpaceX does it. When you have closed
| loop feedback control using velocity and distance measurements
| from radar and vectoring thrusters, it's no longer an
| impossibly difficult ballistic problem. I suppose that
| highlights the necessity of not making assumptions about
| solution methods.
| pjc50 wrote:
| The original statement is correct: the rocket cannot throttle
| down to a small fraction, to an equivalent thrust to the mass
| of the rocket. SpaceX rockets indeed do not "hover" for any
| significant length of time. The trajectory is planned to
| achieve 0 velocity at just above ground level. The feedback
| control comes in because it's impossible to know the exact
| performance and atmospheric characteristics, so if you tried
| to do it by dead reckoning it would be off vertically by tens
| of meters, so the trajectory is continuously adjusted.
| keithalewis wrote:
| Another surprising detail is parents are exempt from child labor
| laws. /s
| dvas wrote:
| That's the thing with details; sometimes you don't know the
| extent or context in which they will occur.
|
| Your perceptiveness at a particular moment could determine a good
| or not-so-good outcome. However, you may not have the expertise
| or familiarity in a domain to spot micro, mini, or normal
| details.
|
| My personal takeaway is to be mindful when you are on autopilot
| to avoid missing details and to avoid keeping your blinders on.
| xg15 wrote:
| > _The first problem you'll encounter is that cutting your 2x12s
| to the right angle is a bit complicated because there's no
| obvious way to trace the correct angles. You can either get
| creative (there is a way to trace it), or you can bust out your
| trig book and figure out how to calculate the angle and position
| of the cuts._
|
| My first thought would be using a string: Fix a string to the
| floor at one end and to the wall with the other end, at the
| places where you want the upper edge of the 2x12 to meet the
| floor and wall (the exact locations are "input parameters" that
| depend on your design, i.e. on how steep you want the stairs to
| be - you can't trace or calculate them)
|
| Then pull the string taut and now you can measure the exact
| length that is suspended in the air (which will be the length of
| the 2x12's upper edge) as well as the inner angles it has with
| the ground and wall (which will be the cutting angles from the
| upper edge towards the lower edge).
|
| Of course even this is easier said than done. I'd assume that
| keeping the string taut and not hanging through might be a
| problem (catenary curve etc).
| matheusmoreira wrote:
| > If you're trying to do impossible things, this effect should
| _chill you to your bones_.
|
| > It means you could be intellectually stuck right at this very
| moment, with the evidence right in front of your face and you
| just can't see it.
|
| This speaks to me. It's terrifying knowing deep in your soul that
| something is possible but getting stuck trying to make it happen.
| When you try to talk to people, you seem a bit unhinged. Like
| some crazy person who's creating his own problems by avoiding the
| easy established solutions. People will straight up tell you it
| can't be done, they will ask you why you can't do it in the
| normal way. It's tempting to take their word for it and just give
| up. However, if you persevere a little and ask the right
| questions, they might just see that it is possible to do things
| differently. If you persevere a lot, you might figure out all the
| details and end up proving that it was possible after all.
|
| I achieved a small victory just like this a few days ago and I'm
| really proud of it, I'm actually preparing to Show HN.
| Misdicorl wrote:
| Every time this is posted I want to rebut the water boiling
| portion. It's finally time.
|
| The author gets the details of boiling water wrong. He commits a
| fairly common error: using his experience of a practical and
| common phenomena to make/guess a technical definition. The
| technical definition of boiling water is simply the temperature
| beyond which liquid water will not go (let's ignore super
| heating- too much detail!). The rest of the exposition is
| unnecessary and wrong given the true definition (although could
| probably be reworked from a cooking perspective)
| pinusc wrote:
| That's fair to point out. However, I don't think it detracts
| from the point: the definition is in some sense a detail,
| because there is a connection between "bubbles forming" and
| "the temperature water will not rise beyond", but it's subtle
| and assuming that one equals the other leads to error. The very
| reason we have that definition is that it's more precise,
| because in the real world there's details that escape narrow
| definitions as seen in school or in the kitchen.
|
| As an aside: I love the bubbling patterns of water as it heats,
| and it's actually a useful skill in the world of tea-making
| (especially in the gongfu tradition) to estimate the
| temperature of water based on the amount and size of bubbles.
| Nowadays I use a temperature-controlled kettle, but in the past
| I would get by with a clear borosilicate glass kettle and
| paying attention to the details, which is fun and rewarding in
| itself--if far less precise.
| wrs wrote:
| The way I read it, that's why you're supposed to imagine it's
| the 1800s. All you have is the simple-sounding concept of
| "boiling", and you're trying to codify it by finding the
| temperature beyond which water will not go. At which point you
| start really paying attention and find the phenomenon is way
| more complex than your initial model of "water is either
| boiling or it isn't".
| Misdicorl wrote:
| But it rather isn't. The temperature keeps going up as you
| add more fire. And then it stops going up even if you add
| more fire. That point is the temperature of interest and was
| from the very start. It isn't hard to find. It isn't hard to
| understand. It's just a bad example for this essay
| dsjoerg wrote:
| > The technical definition of boiling water
|
| is just the start. He starts with "water boils at 100 degC,
| right?" which I expect you'd agree with.
|
| He then _continues_ to work out that, despite the simple
| definition, the everyday-life _experience_ of boiling water is
| nowhere near as simple. Why is it not so simple? Because,
| details.
|
| Which is the point of the whole essay.
|
| > gets the details of boiling water wrong
|
| Can you give an example of a detail he got wrong?
|
| > The rest of the exposition is unnecessary and wrong given the
| true definition
|
| His _goal_ is to explore the details of the everyday-life
| experience of "boiling water" in the everyday sense of
| "boiling" and show how it's more complicated than what the
| simple (technical) definition would lead you to believe.
|
| Part of the trouble is that the word "boiling" means two
| distinct but related things:
|
| 1. Heating liquid so much that all of it transitions to gas
| (your technical definition, restated to be a verb form --
| "boiling water", a gerund phrase, cannot be a temperature, as
| you proposed to define it)
|
| 2. Heating liquid so that _some_ of it is transitioning to gas,
| while the rest of the liquid can be used for cooking
|
| The second sense is what people actually mean when they say
| "I'm going to boil some water" or "Is the water boiling yet?"
| Misdicorl wrote:
| If the discussion was about boiling pasta water I'd be on
| board (e.g. a discussion of the every day). But it's wearing
| the clothing of science and so falls flat (for me). None of
| the details turn out to matter for the real technical
| definition. Amusingly the one detail that does matter- air
| pressure and by proxy elevation- is omitted.
| Xcelerate wrote:
| I'm a data scientist, and it always surprises me how much work
| goes into fields that do not require a degree -- easily just as
| much (or more) thought is required to solve "daily" work tasks.
|
| I needed to redo a closet in my house where the original
| wireframe shelves were not installed correctly and fell out as
| soon as any weight was put on them. First you've got to patch the
| holes. But spackle will show flashing. Ok, so I'll use joint
| compound instead. But there's 27 brands and types, all for
| slightly different purposes. And there might still be flashing if
| you don't use the right type of PVA primer. And you need the
| right sanding tools and, oh, it turns out I suck at applying
| joint compound so I have to call someone anyway to make it look
| like years of expertise went into that.
|
| On to the new shelves. Well I don't want the closet to look like
| I did it myself, so I'll get some floating shelves to make it
| look nice and modern. Wait, $1,200 for a piece of wood?? Can't I
| just find a tree in the backyard and cut that myself? Oh... I
| need specialized equipment to make that look nice too. Whatever
| I'll just order the shelves.
|
| Have the shelves, but now it turns out the tolerances on the
| walls in the closet weren't that tight when it was built. It
| seems like the width of the closet varies quite a bit as you move
| away from the wall. So now there's a gap. And the floating shelf
| metal bracket misses the nearest wall stud by 1/8th of an inch,
| which would halve its load capacity. I'll just drill another hole
| in it. Oh, it's stainless steel and that requires specialized
| equipment and fluid to prevent overheating and...
|
| So yeah, I totally agree with this article in every way. It's
| amazing anything works at all in society.
| dymk wrote:
| The stairs in the article are probably not code compliant, even
| with all that work. The uppermost tread is cut short. Most
| locations require all treads to be the same depth, so his half-
| tread probably won't pass inspection.
|
| The stringers either need to land a little further away from the
| wall, or the stairs the need to be at a slightly steeper angle
| (but check local building code for the max permitted angle!).
|
| I built stairs with a friend years ago, and there are a _lot_ of
| constraints to solve for if you want to build code-compliant
| stairs. A good parametric CAD system was very helpful. We could
| specify overall dimensions: stair rise /run, number of treads,
| thickness and width of the stock. It'd solve for the critical
| dimensions to verify, like tread rise, stair angle, tread depth,
| and the angles to cut the stringer ends to.
| solardev wrote:
| What software could a DIYer use for that?
| dymk wrote:
| I used (and still use, often) Fusion 360
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