Putting Rigid Bodies to Rest
14 comments
·May 29, 2025Cieric
I don't have enough time to read the paper in full right now. But I'm curious if using this they could possibly find the solution to the 3 sided coin problem. I haven't heard anything about it since I watched the matt parker video about it.
Or I guess if anyone else knows the answer, that would also satisfy my curiosity.
Scaevolus
They should be able to simulate it! Here's another answer: https://news.ycombinator.com/item?id=33776796
hnuser123456
Looks like that post author forgot to loop back to the original question once they found a model that fit their own simulations.
Just visually going off the chart, the answer is a "coin" has a 1/3 chance of landing on its edge when its height is 1.7x its radius, or 0.85x its diameter. (the blog author used half-height and the paper he found uses full height)
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spencerflem
I love this !!
Only kinda related but I love having the opportunity to share this website, cataloging every possible fair die: http://www.aleakybos.ch/Shapes.htm
(ie: not the sort of die in the post, they must have identical faces. this thread gave me a new appreciation for the non equal faced dice tho)
iwontberude
I don’t think it gets much better than this. How exceedingly clever.
90s_dev
Does this mean 2d physics simulators are about to get N times faster? Because that'd be cool if N is big enough.
almostgotcaught
> our key observation is that we can identify dynamically stable configurations of a rigid body, and calculate their associated probabilities
> this model is purely geometric, and does not directly account for momentum
answer: no
pvg
Paper https://hbaktash.github.io/files/rolling_dragons_paper.pdf and more related stuff on the page of one of the authors https://hbaktash.github.io/
spwa4
[flagged]
qoez
There's still way more signal there then really any other social network (even youtube is getting slop-y)
ninkendo
I’d never know, every time I follow a twitter link there’s just a full page login form that blocks me from viewing the link. Twitter should be treated like a paywalled site here, IMO. I have no ability to read links like these unless I make an account, which I will never, ever, ever do.
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https://xcancel.com/keenanisalive/status/1925225500659658999