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A new pyramid-like shape always lands the same side up

(www.quantamagazine.org)
594 points robinhouston | 8 comments | 25 Jun 25 20:01 UTC | HN request time: 0.801s | source | bottom
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ChuckMcM ◴[25 Jun 25 21:09 UTC] No.44381861[source]▶
Worst D-4 ever! But more seriously, I wonder how closely you could get to an non-uniform mass polyhedra which had 'knife edge' type balance. Which is to say;

1) Construct a polyhedra with uneven weight distribution which is stable on exactly two faces.

2) Make one of those faces much more stable than the other, so if it is on the limited stability face and disturbed, it will switch to the high stability face.

A structure like that would be useful as a tamper detector.

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1. schiffern ◴[26 Jun 25 05:59 UTC] No.44384580[source]▶

  >useful as a tamper detector
If anyone's actually looking for this, check out tilt and shock indicators made for fragile packages.

https://www.uline.com/Cls_10/Damage-Indicators

https://www.youtube.com/watch?v=M9hHHt-S9kY

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2. p0w3n3d ◴[26 Jun 25 07:18 UTC] No.44385003[source]▶
These shock watches and tilt watchers are quite expensive. I wonder how much must be the package worth to be feasible to use this kind of protection
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3. bigDinosaur ◴[26 Jun 25 07:35 UTC] No.44385100[source]▶
It may not just be monetary value. Shipping something that could be ruined by being thrown around (e.g. IIRC there were issues with covid-19 vaccine suspensions and sudden shocks ruining it) that just won't work may need this indicator even if the actual monetary value is otherwise low.
4. Someone ◴[26 Jun 25 07:47 UTC] No.44385158[source]▶
Did you notice the column indicating number of items per box/carton?

Shockwatch is $170 for 50 items, for example, and the label $75 for 200.

Not dirt cheap, but I guess that’s because of the size of the market.

5. donw ◴[26 Jun 25 15:05 UTC] No.44388146[source]▶
Fun fact: MythBusters used shock watches extensively when testing anything involving impact, because they were massively more reliable than any of their digital instrument.
6. nvalis ◴[26 Jun 25 17:43 UTC] No.44389580[source]▶
If it's about intrusion detection of packaged goods lentils, beans or rice are very useful [0]. Cheap but great tamper detection.

[0]: https://dys2p.com/en/2021-12-tamper-evident-protection.html

7. eastbound ◴[26 Jun 25 19:43 UTC] No.44390601[source]▶
Problem is when transporting tilt watchers, you can’t tilt the package either.
8. numb7rs ◴[26 Jun 25 19:55 UTC] No.44390679[source]▶
These are pretty normal when shipping scientific equipment.