Wednesday, September 23, 2009

Cool Airship Video

The Lockheed P-791.

Gravity Insulators??

I noticed this stone a long time ago on the Tufts campus. A couple of older ladies with pronounced Irish accents read it and pronounced it "a lovely idea", haha.
I wondered at the time how such an outlandish monument ended up at a reputable university. Well Wikipedia Knows All: Gravity Research Foundation

Supersymmetry and Division Algebras

There's a surprising connection between supersymmetry , a hot topic in theoretical physics, and division algebras: the real, complex, quaternion and octonion number systems. Supersymmetry only works in 3,4,6 and 10 space time dimensions. That's because there's a cute little trick which allows us to represent an n+2 dimensional spacetime vector using one number from a division algebra and two additional real numbers. There are only four division algebras - which just happen to have 1,2,4 and 8 dimensions. John Baez Explains It All To You here.