Talk:Oloid

Latest comment: 6 years ago by 2602:306:3B1A:C6D0:42D:52B5:344E:90EB in topic Incorrect model in "related shapes" section

Erroneous statement

edit

The second sentence of the section Kinetics reads as follows:

"While rolling, it develops its entire surface: every point of the oloid touches the plane on which it is rolling, at some point during the rolling movement."

This is simply not true. This statement is footnoted as reference [1] (Dirnböck, Hans; Stachel, Hellmuth (1997), "The development of the oloid" (PDF), Journal for Geometry and Graphics 1 (2): 105–118, MR 1622664), but I cannot find any such statement in this paper.

It is completely clear in any case that points of the oloid lying near the centers of the two generating circles can never touch the plane on which it rolls.

Rather, only its points lying on the boundary of its convex hull can touch the plane.Daqu (talk) 19:04, 15 November 2015 (UTC)Reply

Fixed. Thanks. Next time please do it yourself. - üser:Altenmann >t 19:20, 15 November 2015 (UTC)Reply

Incorrect model in "related shapes" section

edit

The graphic with the rotatable oloid and sphericon contains an incorrect model of the oloid. It's not a convex figure. — Preceding unsigned comment added by 2602:306:3B1A:C6D0:42D:52B5:344E:90EB (talk) 10:25, 11 February 2018 (UTC)Reply