orientable

There's a theorem in knot theory that given any 'tame' knot, there is an orientable surface whose boundary is this knot.

Archive 2010-01-01 Jhadur 2010

It has the mathematical property of being non-orientable.

Totally One-sided 2008

These are the finest closed, non-orientable, boundary-free manifolds sold anywhere in our three spatial dimensions.

hughstimson.org » Blog Archive » Monetizing the Klein Bottle 2008

If it had an odd number of "lobes" then it would be a Klein bottle, but as it has 6, and each lobe flips one side of the surface for the other, one can colour the two sides with different shades consistently, so it has to be orientable.

AM Radio and Miki Gymnast collaborate - Two distinct art languages converse Bettina Tizzy 2008

It has the mathematical property of being non-orientable.

Yisrael Medad can’t take a joke, Wonkette misses the high-road | Jewschool 2007

The ones with even number of twists are orientable with two circular edges with varying linking number, and the odd-numbered twists are non-orientable with a single circular edge that links (knots) itself a varying number of times.

Boing Boing: July 25, 2004 - July 31, 2004 Archives 2004

It has two twists, not one, which means it's an orientable surface (having two unique sides), topologically equivalent to an ordinary circular strip.

Boing Boing: July 25, 2004 - July 31, 2004 Archives 2004

Acme Klein Bottle - Nice site for "the finest closed, non-orientable, boundary-free manifolds sold anywhere in oõr three spatial dimensions."

Pattern, mathematics & games Ray Girvan 2002

Acme Klein Bottle - Nice site for "the finest closed, non-orientable, boundary-free manifolds sold anywhere in oõr three spatial dimensions."

Archive 2002-04-01 Ray Girvan 2002

The Pn, that is the real projective spaces, have a remarkable property: for even dimensions n they are nonorientable, but for odd dimensions orientable.

INFINITY SALOMON BOCHNER 1968