Geometric Algebra

I recently had a bit of an epiphany around GA the other day (and Dual numbers, and Screw Theory with Twists and Wrenches): I realized that I had it all backwards. I’d seen GA as an alternative formulation for projective geometry and for Maxwell’s equations, Dual Numbers for auto-differentiation, and Screw Theory for rigid-body dynamics; the question that had always bothered me was “how in the hell did they manage to take these engineering problems and derive these crazy linear…

If you enjoy geometric algebra, you might like my Julia language implementation Grassmann.jl (features on bivector.net) https://github.com/chakravala/Grassmann.jl

The community is brand new. It's managed by Steven De Keninck (enkimute), the author of the ganga.js framework (https://github.com/enkimute/ganja.js). Check out some examples https://enkimute.github.io/ganja.js/examples/coffeeshop.html...

This is a very nicely designed site, but I have to grumble a little: bivectors aren't a concept unique to geometric algebra! They've been used elsewhere in physics for ages: well before geometric algebra in its current form was developed. (I first encountered them in the Petrov classification of spacetime structures.) So it's a bit awkward to see "bivector.net" as a label for geometric algebra resources. (And they're not alone: the Wikipedia article on bivectors reads as if geometric algebra…