new #Segerman #video on morphing #mechanisms: morphing between wireframe cubes and octahedra (or generally any two dual polyhedra) with scissor and geared mechanisms. The geared mechanism uses his extensible racks to lengthen or shorten the edges in sync, driven by the edges’ rotation with respect to 12 immobile gears. Also, a demonstration of some Borromean rings at the Institut Henri Poincaré.
on 02026-04-19new #Segerman #video extending his expanding-racks approach to three-dimensional expanding objects. Lots of #math about three-dimensional symmetry groups and crystal structures.
on 02026-01-06#Segerman #video #toread about a pseudo-scissor linkage #mechanism using gears instead of half of the links
on 02025-10-20#Segerman #video #toread about #circus-arts
on 02025-10-18#Segerman #video about single-degree-of-freedom deployable #mechanisms that fold up into an icosahedron, made with SLS #3D-printing from nylon
on 02025-10-18#Segerman #video on the Cannon–Thurston map and the complementary space of the figure-eight knot. #math #toread
on 02025-10-15#Segerman #video on “wild” knots such as the wild slipknot which cannot be topologically deformed into polygons. Introduction to knot theory. #toread #math
on 02025-10-15#Segerman #video showing Sydler’s π/4 polyhedron from 01965, constructed by Matthias Goerner, in which all dihedral angles are 90° except for one, and talking-heading about the Dehn invariant. #math #geometry
on 02025-10-15#video by #Segerman about expanding racks, an expanding truss made out of telescoping rack-and-pinion #mechanisms. For varying speeds of expansion in different parts of the truss, he can use different numbers of racks, or he can use proportionally different sizes of pinions (making the teeth of the gears larger or smaller).
on 02025-06-11#Segerman #video about Cannon-Thurston maps (“naturally occurring space-filling curves”)
on 02024-09-10#Segerman #video #toread on braiding gears, based on gripping gears. Insanely ingenious #mechanisms.
on 02024-09-10#Segerman #video: a “flórice,” a sort of flower of cyclide-shaped bananas (made by #3D-printing) that slide smoothly between being a sphere and being a disc, propelled by bevel gear #mechanisms. He calls it “slide-glide cyclides”.
on 02024-09-10#video by #Segerman about a maze (“dodecahedral holonomy”) where the “rook” you move around has arms sticking out so that which edges it can traverse depends on its state of rotation, which varies when it travels a closed circuit, providing a 120-vertex graph. Generatively designed with Grasshopper after his Python code spent several hours designing the maze.
on 02024-06-25