340 likes | 588 Views
G4G9. Carlo H. Séquin. The Beauty of Knots. EECS Computer Science Division University of California, Berkeley. Classical Knot Tables. Flat (2.5D), uninspiring, lack of symmetry …. Trefoil Knot. Figure-8 Knot Bronze, Dec. 2007 Carlo S é quin. 2 nd Prize, AMS Exhibit 2009.
E N D
G4G9 Carlo H. Séquin The Beauty of Knots EECS Computer Science Division University of California, Berkeley
Classical Knot Tables • Flat (2.5D), uninspiring, lack of symmetry …
Figure-8 KnotBronze, Dec. 2007Carlo Séquin 2nd Prize, AMS Exhibit 2009
“The Beauty of Knots” • Make aesthetically pleasing artifacts! Undergraduate research group in 2009 • What is the most symmetrical configuration? • What is the most 3-dimensional configuration?
Some Results Emphasizing Symmetry Knot 77 Knot 74
Knot Transformations Bring out special, desirable qualities: • A graceful “evenly-spaced” curve:Minimize electrostatic repulsion potential on a flexible wire. • Tightest configuration:Pull tight a rope of fixed diameter without self-intersections. • The least “wiggly” curve:Minimize the arc-length integral of curvature squared. • The most 3D-filling configuration:Wrap knot around a sphere or a cylinder;Turn configuration inside out (point inversion);Play with wires, alu-foil, pipe cleaners!
“Signature Knot” for G4G9 • Has to be a 9-crossing knot … -- but which one ?
the same Knot ! It has 3-fold symmetry! “Signature Knot” for G4G9 … a 9-crossing knot: Knot 940
Knot 940: “Chinese Button Knot” • It has interesting 3D properties !
ChineseButton Knot(Knot 940)Bronze, Dec. 2007Carlo Séquincast & patina bySteve Reinmuth
Knot 940 in Ribbon Form • Will be the subject of some hands-on “constructivist activities” on Fri./Sat. pm.
From Simple Knots to Complicated Knots • “Hilbert Cube 512” – looks complicated … but it is not; -- just a simple, unknotted loop!
Generating Complicated Knots Is there a procedure to make knots of arbitrary complexity…? • Perhaps by fusing simple knots together… • Perhaps by applying recursive techniques… • Start with: 2.5D - Celtic Knots
Another Approach: Knot-Fusion • Combine 3 trefoils into a 12-crossing knot
Another Approach: Mesh-Infilling ... • Robert Fathauer, Bridges Conference, 2007 Map “the whole thing” into all meshes of similar shape
2.5D Recursive (Fractal) Knot • Robert Fathauer: “Recursive Trefoil Knot” Trefoil Recursion 3 views step
Result after 2 more recursion steps Mark crossings over/under, form alternating knot Recursive Figure-8 Knot (4 crossings) Recursion step
Recursive Figure-8 Knot • Scale the stroke-width proportional to recursive reduction
From 2D Drawings to 3D Sculpture • Too flat ! Switch plane orientations
Recursive Figure-8 Knot 3D • Maquette emerging from FDM machine
Recursive Figure-8 Knot • 9 loop iterations
Is It Math ?Is It Art ? • it is:“KNOT-ART”