Abstract. I will define "meta-groups" and explain how one specific meta-group, which in itself is a "meta-bicrossed-product", gives rise to an "ultimate Alexander invariant" of tangles, that contains the Alexander polynomial (multivariable, if you wish), has extremely good composition properties, is evaluated in a topologically meaningful way, and is least-wasteful in a computational sense. If you believe in categorification, that's a wonderful playground.
All the terms used in the above paragraph will be defined during my talk.
Handout: beta.html, beta.pdf, beta.png. Sources: beta.zip. Pensieve: 2012-08.