Henry Segerman @henryseg@mathstodon.xyz
Mathematician working mostly in three-dimensional geometry and topology, and mathematical artist working mostly in 3D printing and virtual reality.
In the spirit of getting carried away, here is the Making of "The Making of "Peace for Triple Piano"", which describes the making of "The Making of "Peace for Triple Piano"", which describes the making of "Peace for Triple Piano". https://youtu.be/PDkbk4OILSw
A non-spherical, circular version of “Peace for Triple Piano”, an exploration of symmetry through time and space, with @vihartvihart. https://youtu.be/g3X0d5NUjjA
The "Making of" video Vi Hart and I made for our space-time symmetry video, "Peace for Triple Piano". https://www.youtube.com/watch?v=x1zJoU6Luss
New video with Vi Hart: an exploration of symmetries through space and time, involving a spherical camera, the map z->z³, a piano, Dona nobis pacem, three copies of Vi and two copies of me.
https://www.youtube.com/watch?v=HcRW3FMuttY
An optical illusion, made with a spherical ("360") camera. With Alexa Meade and Dan Ariely. https://youtu.be/EahZSQmcs_s https://mathstodon.xyz/media/TJODzd57-J8O7SflWU4
I have been playing at generating snowflakes using cellular automata.
Just in time for Christmas (if they're into this kind of thing), a new kind of expanding mechanism! http://shpws.me/Pi30 . More info: https://youtu.be/bEVHVzrQ_PM
Sneak preview of a mechanism project I’ve been working on for a while.
https://mathstodon.xyz/media/xo09DAkqbXhq_glwZO0
It’s that time of the year again.
https://mathstodon.xyz/media/wXXiuYS5K0f185itiN8
Send/Receive
Stereographic projection of the latitude/longitude grid on the sphere.
Source code: http://community.wolfram.com/groups/-/m/t/1206885 https://mathstodon.xyz/media/6W6BEU7iT8DNDBBxdYc
New @numberphile video up with me talking about - you guessed it - juggling: https://www.youtube.com/watch?v=7dwgusHjA0Y&feature=youtu.be - 45 minutes, over 2k views. Wow!
And finally, the dramatic conclusion to my series on Heesch numbers: does there exist a convex pentagon that can be surrounded, but doesn't tile the plane, and admits a surround that's edge-to-edge? Heesch's original 1968 shape does all of the above except the edge-to-edge part. http://isohedral.ca/heesch-numbers-part-4-edge-to-edge-pentagons/ https://mathstodon.xyz/media/a0bUlDZY_utSfkXzkbs
The story of Heesch numbers continues in two posts. In http://isohedral.ca/heesch-numbers-part-2-polyforms/, I compute Heesch numbers of polyominoes and polyiamonds in search of interesting new examples; in http://isohedral.ca/heesch-numbers-part-3-bamboo-shoots-and-ice-cream-cones/, I present a new family of simple polygons, all with Heesch number 1.
I had to reconstruct this gif by Bill Gosper in GeoGebra to believe it.
Construct the tangent to a given point on a circle without using a compass.
https://ggbm.at/GJAkqvTb https://mathstodon.xyz/media/ekv6ASMGaZHCofkExVo
HyperRogue 10.0 is released! More interesting mirrors, new modes with more resource management or no battle. http://zenorogue.blogspot.com/2017/07/hyperrogue-100-is-released.html https://mastodon.social/media/78a_XNcXctGyDdVSup8
Matt Parker made a video about our Brilliant Geometry exhibition in Edinburgh: https://www.youtube.com/watch?v=LOVzytir7bM
Intertwine
Stereographic projection of 30 congruent spheres centered on equally-spaced points along a trefoil knot in the 3-sphere.
Source code: http://community.wolfram.com/groups/-/m/t/1144941 https://mathstodon.xyz/media/WZXefyrbf7UoGGuoaWk
Topographical topology at the Arches National Park in Utah! https://youtu.be/-1_VYcJGvKU
Time to justify my presence here...
The Heesch number of a shape is the maximum number of layers of copies of that shape by which you can surround it. Heesch's Problem asks which positive integers can be Heesch numbers. I'll show a few fun new results over a series of blog posts; today, I offer a basic introduction to the topic. http://isohedral.ca/heesch-numbers-part-1/
