Swings and Roundabouts

Odd.

On Monday evening, I could not draw a thing correctly. Seriously, if you had put a cylinder in front of me square on, I’d have not been able to draw a recognizable representation of it.

This morning, on the bus, I noticed this interesting face inviting me to draw it (the gentleman currently in possession of it was dozing for some of the trip), and in a short time this sketch (click to enlarge) popped out from under my pencil. Funny old world…

-cvj Click to continue reading this post

Spin

This week marks a landmark in the class (Introduction to Quantum Field Theory) since it focuses on the seminal work of one my heroes, Paul Dirac, who quietly went about his business of puzzling over the issue of how to find an equation that describes the properties of electrons (particles of spin one-half), and in finding what is now called the Dirac equation (see snapshot from my notes on right), uncovered a hugely rich and bright cornerstone of fundamental physics. It is famously described as a sort of square root of the relativistic wave equation known at the time – the Klein-Gordon equation – and in that way of thinking you quickly arrive at the idea of anti-particles (as did Dirac), since taking a square root leads to two solutions (both +2 and -2 square to give you 4). One solution turned out to be the electron, and the other leads (by an appropriate path of reasoning) to its anti-particle, the positron*.

Besides leading inevitably to anti-particles, the equation (which Dirac pursued in […] Click to continue reading this post