Supposedly, during the Middle Ages, while undergraduates struggled with learning to multiply and divide Roman numberals, the graduate students learned the more "advanced" Arabic numerals.

It was only by great struggle that Hamilton finally invented quaternions (essentially, vectors).

Could twistors be to vectors, what arabic numbers are to roman numerals? Perhaps!

If you link to Andrew Hodges's page, you can see what Ed Witten is currently doing with twistors.

So what ARE twistors? A primer is provided by Fedja Hadrovich, but I find the jpg equations hard to read.

So, I have created a pdf version of Fedja's twistor primer, which you can download, print, and study.

Only one problem: since I'm not on top of twistors yet myself, I've probably misread some of the equations, particularly superscripts and subscripts. Egregious example: I have NO IDEA what the superscript is really supposed to be at the start of the final equation!

I will be grateful if Fedja (or anyone else) gives me corrections so I can post a corrected verion.