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Comment by goldcd | Hacker News Reader

No - it's Duplo and designed to be abused. It's not going to suddenly explode into shards of plastic in the middle of the night.

Probably need to define "too much tension". Is a bit of tension that enables you to build the thing you want and couldn't otherwise, a good or a bad thing? (e.g. maybe I want a spiral)

I'd have thought if overly tensioned, once tolerances were overcome, the track would develop a camber. Maybe build on a perfectly flat, frictionless surface and then if your track isn't perfectly level you know there's tension.

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It's a math problem. Read TFA.

It’s an engineering program masquerading as a math problem. Long enough racks can have misalignment without noticeable issues because each segment has some play.

engineering takes into account material properties. the engineering solution is "no, that tension is way inside the design tolerances"

the stack overflow answers are math.

The top rated answer was math, but it ignored the possibility that a section of track would be under tension to avoid intersecting with itself. For a mathematical curve that’s no issue, but physical objects add additional constraints to the problem.

No. It's the other way around. If someone did FEA on the track and showed you a stress map, it would be obvious how uninteresting framing it as an engineering problem is.

The question opens with a question about the material properties of a physical object and many of the replies address that.

As a pure math problem it’s got a few constraints such as the track not physically intersecting with itself which go beyond the stated question.

So yes it’s a toy problem, but one constrained by real world objects.

It's a real world problem, but one constrained by toy objects.

Yeah, that's human interest to get you interested in the problem and how it occurred to the author. Do you think the trolley problem is about trolley cars on rails with switches?

The most upvoted response was objectively wrong due to real world constraints.

The real world is irrelevant in the trolly problem or the 4 color theorem etc.

You may personally be interested in it as a purely mathematical problem, but he’s looking for a real world answer so poor abstractions are useless. On the other hand “I would first check for track flatness. When locked in with extra effort, the loop will warp a little, basically going into 3d instead of flat 2d.” is a useful shortcut.

> he’s looking for a real world answer

Based on his history in StackExchange, it is unlikely Lezzup is looking for a real world answer. The top tags of his posts are: mathematics, sudoku, geometry, logical-deduction, sequence, and enigmatic-puzzle.

https://puzzling.stackexchange.com/users/84683/lezzup

“I am sure this could be calculated mathematically, but I prefer a more quick, practical way.”

As it seems that English is not his first language, and that quote you offered appears to contradict "I know I could just take one piece out, and put it back in to feel it myself, but I am looking for a more logical way, so I am able to reason it", and based on the provenance of his other postings, these appeals to contort the question into some kind of uninteresting material science one are not credible.

There’s no contradiction to “logical methods” including things like noticing the pieces curve into 3D space because they don’t fit together. Saying you don’t want to rely on taking it apart doesn’t invalidate simple inspection.

The fastest solution is going to be a combination of heuristics and multiple forms of mathematical modeling. Something like 1 does it look reasonable, 2 do the internal angles add up correctly, then 3 a more precise assessment based on actual curves and piece lengths. Doing 3 when it already failed 2 is redundant.

I’d argue is a chemistry problem, or maybe material science, as the type of plastic dictates the stress tolerance.

and I quote "I am sure this could be calculated mathematically, but I prefer a more quick, practical way."

"Too much tension" is not a math problem. It's an engineering problem (and a poorly defined one, at that).

Try thinking for a few seconds before posting such a meritless dismissal.

goldcd> It's not going to suddenly explode into shards of plastic in the middle of the night.

That gives you the impression that goldcd fully comprehended the scope of the inquiry?

TFA: "I am sure this could be solved mathematically, but I prefer something quick and practical."

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