# Talk:Alternating knot

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Field:  Topology

• Who invented the concept? Who first proved something non-trivial about alternation? Who first proved a knot to be non-alternating?
• How does one prove a knot is non-alternating? I suspect the polynomial invariants identify non-alternating knots, but I don't know.
• What's the simplest non-alternating link? Pictures?
• Are there any theorems that have "alternating" as a hypothesis?

--Dbenbenn 03:53, 3 Dec 2004 (UTC)

Some of the questions are answered by now. Some stuff to be added: explanation of how to show a knot is non-alternating (Alexander polynomial can be used). Alternating knots go back to Tait, and even before him to celtic knots and artwork. --C S (Talk) 13:42, 9 January 2006 (UTC)

According to 01:11 point of this video: https://www.youtube.com/watch?v=PODjlS_hAvk

Ralph Fox asked "What is an alternating knot?" in circa 1961. A quick search reveals that Ralph Fox wrote two articles in 1961 on knot theory:

Some problems in knot theory, Topology of 3-manifolds and related topics

A quick trip through knot theory, Topology of 3-manifolds and related topics

So I guess that's where that quote came from? Cosmia Nebula (talk) 08:10, 30 December 2015 (UTC)

## Does the picture shown actually depict a nonalternating knot?

It seems to me the picture is of an alternating knot, just with a nonalternating drawing. By contrast the knot 8_19 on Knot Atlas (http://katlas.org/w/images/c/c9/8crossing-symmetrical-nonalternating.png) does seem to be nonalternating. Should we use this picture instead? — Preceding unsigned comment added by 2601:644:402:440:CD6E:FA45:389B:2496 (talk) 08:11, 15 March 2017 (UTC)