|提及的人：||O I︠A︡ Viro; Virginia Ragsdale; Virginia Ragsdale; O I︠A︡ Viro|
Jesús A De Loera; Frederick J Wicklin; University of Minnesota. Geometry Center.
|描述：||1 videocassette (8 min.) : sd., col. ; 1/2 in. + notes (1 sheet)|
|責任：||written and produced by Jesús A. De Loera and Frederick J. Wicklin.|
This animated video explains new developments concerning Hilbert's sixteenth problem, still unsolved, dealing with ways nonsingular level sets of polynomials can be arranged in the projected plane. Mathematician Virginia Ragsdale had conjectured an upper bound on the number of topological circles resulting from algebraic curves of degree 2k. After almost 90 years, Oleg Viro has proposed a new combinatorial method for constructing curves, known as patchworking, which has shown counter-examples to the Ragsdale Conjecture.