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Reality has a surprising amount of detail (2017)

johnsalvatier.org

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Re: Reality has a surprising amount of detail (2017)

#101

Post by taneq »

monochromatic wrote: post #83
tome wrote: post #80

Earlier quoted context omitted.

Have you actually tried turning a bicycle without countersteering? I have, the last time the topic was discussed on HN. I found I was able to turn without any perceptible countersteer. It's technically possible that I do have to countersteer for a small number of miliseconds over a small number of milimeters, but my experience leads me to doubt it.

A moped (and I assume a motorcycle) is a lot harder to turn without countersteering. I’m not sure if that’s because it’s more massive or what. Anyway, learning to ride a moped was when I first consciously discovered countersteering. It made things a lot easier after that point.

The geometry is set up to be stable at a higher speed. Even then some sports bikes require a steering dampener to prevent "speed wobbles" (which, yes, are an actual thing and are much worse at 260kph than at 30kph on your BMX when you're a kid.)

Re: Reality has a surprising amount of detail (2017)

#102

Post by hornbaker »

foxhop wrote: post #71

This is an incredible read, very thought invoking. I've never replaced stairs but I have learned enough of the "details" by repairing them (or being aware of them) to know it's a really hard to get right. A single 1/4 inch difference between two steps can feel wrong; a 1/2 inch difference and people will likely stumble or tumble down them on their first approach. Our intuition and pattern recognition impacts how we s…

A gif of what happens when one step is just slightly too high:

https://imgur.com/hl3YWJD

Re: Reality has a surprising amount of detail (2017)

#103

Post by hornbaker »

CurtMonash wrote: post #8

There's something of a connection here to Zen and the Art of Motorcycle Maintenance. Two examples come to mind: 1. The narrator thinks it's important to have in your toolset hammers of multiple hardness, because your hammer should be softer than whatever material you're hammering on at the time. At least, that's how I remember it; I might well be wrong about -- well, about the DETAILS of that example. Please correct…

For fans of extreme detail, I'd recommend The Mezzanine by Nicholson Baker[0]. Iirc, he devoted several pages to the feeling of the curls of a brown paper bag carried in his hand.

0: https://www.amazon.com/Mezzanine-Nicholson-Baker/dp/08021449...

Re: Reality has a surprising amount of detail (2017)

#104

Post by dingo_bat »

littlestymaar wrote: post #76
jasode wrote: post #53

>Do you remember the insights that were crucial in learning to ride a bike or drive? The author mentioned bicycles and inadvertently missed an opportunity to show another "unknown reality" that beautifully illustrates his point. Consider typical adults (not physicists) with 20+ years of bicycle riding. If you ask them, "how does a bicycle turn?" , they'd respond that "you just lean into the direction of the turn and…

> If one human is teaching another human, you can leave the "countersteering" detail out and it won't matter. The 200 years of people learning how to ride bicycles is evidence of that. This is actually a well-known fact about motorcycle, and it's taught in driving schools. It's just that their is no bicycle driving school and people just figure it by themselves. I'm pretty sure it takes more time though.

I don't think regular driving schools teach you to countersteer when you turn.

Re: Reality has a surprising amount of detail (2017)

#105

Post by unavoidable »

cricalix wrote: post #34
tempestn wrote: post #14

Having never done any carpentry nor googled the answer, the first thing that's coming to mind is to place the board at the angle you want, then use a straight edge (like a level) extended out from the floor of the upper story to trace a line on the board. Cut the board, then flip it over so that cut side is on the bottom, and then repeat the process to cut the top. Edit: I guess my first line will read as a disclaime…

I think you've got a slight problem with this approach, that a diagram should illustrate if you draw the board as a rectangle and not a line. Thought experiment time: Let us assume that you rest the board in such a manner that the angle between the edge of the board and the vertical wall is 45 degrees. The edge of the board is tangential to the corner of the wall and the upper floor, and you scribe the horizontal lin…

Another problem with reality: most wall-floor angles are not exactly 90 degrees! Anyone who has tried to build custom cabinetry and shelving can attest to this.

Re: Reality has a surprising amount of detail (2017)

#106

Post by CurtMonash »

dsr_ wrote: post #35
CurtMonash wrote: post #8

There's something of a connection here to Zen and the Art of Motorcycle Maintenance. Two examples come to mind: 1. The narrator thinks it's important to have in your toolset hammers of multiple hardness, because your hammer should be softer than whatever material you're hammering on at the time. At least, that's how I remember it; I might well be wrong about -- well, about the DETAILS of that example. Please correct…

He’d been innovating extensively. He’d been having trouble with students who had nothing to say. At first he thought it was laziness but later it became apparent that it wasn’t. They just couldn’t think of anything to say. One of them, a girl with strong-lensed glasses, wanted to write a five-hundred-word essay about the United States. He was used to the sinking feeling that comes from statements like this, and sugge…

Thanks for finding that!

Re: Reality has a surprising amount of detail (2017)

#107

Post by taneq »

CurtMonash wrote: post #8

There's something of a connection here to Zen and the Art of Motorcycle Maintenance. Two examples come to mind: 1. The narrator thinks it's important to have in your toolset hammers of multiple hardness, because your hammer should be softer than whatever material you're hammering on at the time. At least, that's how I remember it; I might well be wrong about -- well, about the DETAILS of that example. Please correct…

Thanks for reminding me, I really need to re-read that book.

Re: Reality has a surprising amount of detail (2017)

#108

Post by gglitch »

codingdave wrote: post #39
DanielBMarkham wrote: post #10

Something I've noticed now that we're all communicating online in written form: a lack of people saying "I don't know" It seems that everybody knows everything. Whatever the issue, a little bit of Googling and suddenly you know all there is to know. Even more wondrous, no matter what position you take on anything, some more search engine Kung Fu and you can find a hundred people willing to support you with arguments,…

Why would I jump into a thread, on any site, just to say I don't know? There are thousands of threads just on HN that I just let scroll by without participating because I don't know enough to add to the discussion. Explicitly calling out my lack of knowledge on every thread would serve no purpose to anybody. Online written communications will never follow the same patterns as direct communication, and that is a good…

I doubt gp is encouraging people to jump into threads to say they don't know something. I imagine the insight is that online communication lends itself too well to an unfavorable s/n, one that militates against reasoned discussion.

Re: Reality has a surprising amount of detail (2017)

#109

Post by TremendousJudge »

serpix wrote: post #2

This here is why estimation of tasks (in software) is IMHO futile hand waving. There is always unknown unknowns, snags and hangups which may surprise everyone. Everybody who actually creates or makes something can agree that that stuff is hard, really hard but oh so rewarding!

the point of good estimation is not the estimation itself (which is not very reliable), but actually thinking about what the details of the task are. I think the estimation should be seen as an excuse to partake in this exercise

Re: Reality has a surprising amount of detail (2017)

#110

Post by dingo_bat »

hwillis wrote: post #100
goatlover wrote: post #95

And this is the reason I'm somewhat skeptical of predictions of future superhuman AI. The world is complicated and full of all kinds of details we overlook. Creating a general purpose AI that's able to bootstrap itself to being better than all humans at everything seems like ignoring all the difficulties it will run into. It's easy to imagine when not taking everything into account, but extremely hard to realize. And…

If anything it should make you feel the opposite. The brain is an extremely effective optimizer that solves these problems in a way that is opaque to us. We find it very difficult to solve them. An AI is an "unlocked" brain. It can see all the things that it does and then see how it does them. If it learns to ride a bike -and if it's a humanlike AI, it will be able to- it'll be able to see exactly what it does and bu…

Except looking inside a neural network is almost impossible. For example, google photos still turns mum if you search "gorilla". They could not figure out wtf was wrong with the recognition networks and had to just blacklist the keywords.

https://www.wired.com/story/when-it-comes-to-gorillas-google...

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