This is a unknot described by Morwen Thistlethwaite.
Traced by <a href="//commons.wikimedia.org/wiki/User:Stannered" title="User:Stannered">User:Stannered</a>
2007-03-25
<a href="https://en.wikipedia.org/wiki/Image:Thistlethwaite_unknot.png" class="extiw" title="en:Image:Thistlethwaite unknot.png">en:Image:Thistlethwaite unknot.png</a>