The Self-righting Tetrahedron

[Will Gilmore]

I came across this article and thought it would be appreciated here.
A New Pyramid-Like Shape Always Lands the Same Side Up | Quanta Magazine https://www.quantamagazine.org/a-new-pyramid-like-shape-always-lands-the-same-side-up-20250625/

And here is a paper desk l describing it.
Building a monostable tetrahedron https://arxiv.org/html/2506.19244v1

The Gömböc, another shape that is monostable.

-Will

 

[mc_rash]

Interesting, a behavior we desire to achieve when building a boat..

I like the simplicity of the tetrahedon, but I find the Gömböc more fascinating because of it's "unpredictable" shape from which one cannot see immediatly the self righting behavior.

 

[messabout]

Gombocs and Tortoises are fascinating studies.

 

[jehardiman]

While the shapes and weight distributions are intersiting on land, they really have no place at sea where the water surface is rarely flat or perpendicular to gravity. We have enough trouble keeping isodense cubes upright (see this thread initial stability of a ship https://www.boatdesign.net/threads/initial-stability-of-a-ship.47718/page-3#post-645031 ) so building something that constantly rolls over in certian seaways is a useless curosity.

 

[Silvertooth]

Mayu Phillips is looking for a skiff for this sort of thing