Since the beginning of version control, people have been using VCSs to manage websites. It works pretty well, because the process of web development is similar to the process of programming. Heck, with the advent of dynamic websites these days, often half of web development is programming. But web developers have one peculiar requirement that most...

I just realized that in my last post I sort of neglected to address the main question. So what is an einbein? Turns out the answer is on the next page of the Green, Schwartz, and Witten textbook: the einbein is the induced metric, normally written , where and range over the coordinates in the parametrization of the worldline/worldsheet/whatever. A...

You know that feeling you get when you're reading a textbook and the authors start pulling equations out of thin air on the second page of the second chapter? No? Well then, my congratulations on having a life.

But seriously, I came across a gem of this sort in Superstring Theory volume 1 by Green,...

I just ran into a funny problem where I was unable to run GUI apps as root, although I had no trouble using KDE and its applications as my normal non-root user. I'd get various sorts of error messages, like "unable to open display :0" or "cannot...

I've just been doing something that probably should never be done in Python (again), and I figured it might be useful to record this little snippet for posterity. Many Python programmers are probably familiar with decorators, which modify functions by wrapping them with other functions. For example, if you want to print 'entering' and 'exiting' to...